Quagga is an advanced routing software packagethat provides a suite of TCP/IP based routing protocols. This is the Manualfor Quagga 1.2.0. Quagga is a fork of GNU Zebra.

Permission is granted to make and distribute verbatim copies of thismanual provided the copyright notice and this permission notice arepreserved on all copies.

Permission is granted to copy and distribute modified versions of thismanual under the conditions for verbatim copying, provided that theentire resulting derived work is distributed under the terms of apermission notice identical to this one.

Permission is granted to copy and distribute translations of this manualinto another language, under the above conditions for modified versions,except that this permission notice may be stated in a translationapproved by Kunihiro Ishiguro.

1 Overview

Quagga is a routing software package thatprovides TCP/IP based routing services with routing protocols support suchas RIPv1, RIPv2, RIPng, OSPFv2, OSPFv3, IS-IS, BGP-4, and BGP-4+ (see Supported RFCs). Quagga also supports special BGP Route Reflector and Route Serverbehavior. In addition to traditional IPv4 routing protocols, Quagga alsosupports IPv6 routing protocols. With SNMP daemon which supports SMUX and AgentXprotocol, Quagga provides routing protocol MIBs (see SNMP Support).

Quagga uses an advanced software architecture to provide you with a highquality, multi server routing engine. Quagga has an interactive userinterface for each routing protocol and supports common client commands. Due to this design, you can add new protocol daemons to Quagga easily. Youcan use Quagga library as your program’s client user interface.

Quagga is distributed under the GNU General Public License.

1.1 About Quagga

Today, TCP/IP networks are covering all of the world. The Internet hasbeen deployed in many countries, companies, and to the home. When youconnect to the Internet your packet will pass many routers which have TCP/IProuting functionality.

A system with Quagga installed acts as a dedicated router. With Quagga,your machine exchanges routing information with other routers using routingprotocols. Quagga uses this information to update the kernel routing tableso that the right data goes to the right place. You can dynamically changethe configuration and you may view routing table information from the Quaggaterminal interface.

Adding to routing protocol support, Quagga can setup interface’s flags,interface’s address, static routes and so on. If you have a small network,or a stub network, or xDSL connection, configuring the Quagga routingsoftware is very easy. The only thing you have to do is to set up theinterfaces and put a few commands about static routes and/or default routes. If the network is rather large, or if the network structure changesfrequently, you will want to take advantage of Quagga’s dynamic routingprotocol support for protocols such as RIP, OSPF, IS-IS or BGP.

Traditionally, UNIX based router configuration is done byifconfig and route commands. Status of routingtable is displayed by netstat utility. Almost of these commandswork only if the user has root privileges. Quagga has a different systemadministration method. There are two user modes in Quagga. One is normalmode, the other is enable mode. Normal mode user can only view systemstatus, enable mode user can change system configuration. This UNIX accountindependent feature will be great help to the router administrator.

Currently, Quagga supports common unicast routing protocols, that is BGP,OSPF, RIP and IS-IS. Upcoming for MPLS support, an implementation of LDP iscurrently being prepared for merging. Implementations of BFD and PIM-SSM(IPv4) also exist, but are not actively being worked on.

The ultimate goal of the Quagga project is making a productive, quality, freeTCP/IP routing software package.

1.2 System Architecture

Traditional routing software is made as a one process program whichprovides all of the routing protocol functionalities. Quagga takes adifferent approach. It is made from a collection of several daemons thatwork together to build the routing table. There may be severalprotocol-specific routing daemons and zebra the kernel routing manager.

The ripd daemon handles the RIP protocol, whileospfd is a daemon which supports OSPF version 2.bgpd supports the BGP-4 protocol. For changing the kernelrouting table and for redistribution of routes between different routingprotocols, there is a kernel routing table manager zebra daemon. It is easy to add a new routing protocol daemons to the entire routingsystem without affecting any other software. You need to run only theprotocol daemon associated with routing protocols in use. Thus, user mayrun a specific daemon and send routing reports to a central routing console.

There is no need for these daemons to be running on the same machine. Youcan even run several same protocol daemons on the same machine. Thisarchitecture creates new possibilities for the routing system.

+----+  +----+  +-----+  +-----+
|bgpd|  |ripd|  |ospfd|  |zebra|
+----+  +----+  +-----+  +-----+
                            |
+---------------------------|--+
|                           v  |
|  UNIX Kernel  routing table  |
|                              |
+------------------------------+

    Quagga System Architecture

Multi-process architecture brings extensibility, modularity andmaintainability. At the same time it also brings many configuration filesand terminal interfaces. Each daemon has it’s own configuration file andterminal interface. When you configure a static route, it must be done inzebra configuration file. When you configure BGP network it mustbe done in bgpd configuration file. This can be a very annoyingthing. To resolve the problem, Quagga provides integrated user interfaceshell called vtysh. vtysh connects to each daemon withUNIX domain socket and then works as a proxy for user input.

Quagga was planned to use multi-threaded mechanism when it runs with akernel that supports multi-threads. But at the moment, the thread librarywhich comes with GNU/Linux or FreeBSD has some problems with runningreliable services such as routing software, so we don’t use threads at all. Instead we use the select(2) system call for multiplexing theevents.

1.3 Supported Platforms

Currently Quagga supports GNU/Linux and BSD. Porting Quaggato other platforms is not too difficult as platform dependent code shouldmost be limited to the zebra daemon. Protocol daemons are mostlyplatform independent. Please let us know when you find out Quagga runs on aplatform which is not listed below.

The list of officially supported platforms are listed below. Note thatQuagga may run correctly on other platforms, and may run with partialfunctionality on further platforms.

GNU/Linux
FreeBSD
NetBSD
OpenBSD

Versions of these platforms that are older than around 2 years from the pointof their original release (in case of GNU/Linux, this is since the kernel’srelease on kernel.org) may need some work. Similarly, the following platformsmay work with some effort:

Solaris
Mac OSX

Also note that, in particular regarding proprietary platforms, compilerand C library choice will affect Quagga. Only recent versions of thefollowing C compilers are well-tested:

GNU’s GCC
LLVM’s clang
Intel’s ICC

1.4 Supported RFCs

Below is the list of currently supported RFC’s.

RFC1058: Routing Information Protocol. C.L. Hedrick. Jun-01-1988.
RF2082: RIP-2 MD5 Authentication. F. Baker, R. Atkinson. January 1997.
RFC2453: RIP Version 2. G. Malkin. November 1998.
RFC2080: RIPng for IPv6. G. Malkin, R. Minnear. January 1997.
RFC2328: OSPF Version 2. J. Moy. April 1998.
RFC2370: The OSPF Opaque LSA Option R. Coltun. July 1998.
RFC3101: The OSPF Not-So-Stubby Area (NSSA) Option P. Murphy. January 2003.
RFC2740: OSPF for IPv6. R. Coltun, D. Ferguson, J. Moy. December 1999.
RFC1771: A Border Gateway Protocol 4 (BGP-4). Y. Rekhter & T. Li. March 1995.
RFC1965: Autonomous System Confederations for BGP. P. Traina. June 1996.
RFC1997: BGP Communities Attribute. R. Chandra, P. Traina & T. Li. August 1996.
RFC2545: Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing. P. Marques, F. Dupont. March 1999.
RFC2796: BGP Route Reflection An alternative to full mesh IBGP. T. Bates & R. Chandrasekeran. June 1996.
RFC2858: Multiprotocol Extensions for BGP-4. T. Bates, Y. Rekhter, R. Chandra, D. Katz. June 2000.
RFC2842: Capabilities Advertisement with BGP-4. R. Chandra, J. Scudder. May 2000.
RFC3137: OSPF Stub Router Advertisement, A. Retana, L. Nguyen, R. White, A. Zinin, D. McPherson. June 2001

When SNMP support is enabled, below RFC is also supported.

RFC1227: SNMP MUX protocol and MIB. M.T. Rose. May-01-1991.
RFC1657: Definitions of Managed Objects for the Fourth Version of theBorder Gateway Protocol (BGP-4) using SMIv2. S. Willis, J. Burruss,J. Chu, Editor. July 1994.
RFC1724: RIP Version 2 MIB Extension. G. Malkin & F. Baker. November 1994.
RFC1850: OSPF Version 2 Management Information Base. F. Baker, R. Coltun.November 1995.
RFC2741: Agent Extensibility (AgentX) Protocol. M. Daniele, B. Wijnen. January 2000.

1.5 How to get Quagga

The official Quagga web-site is located at:

http://www.quagga.net/

and contains further information, as well as links to additionalresources.

Quagga is a fork of GNU Zebra, whoseweb-site is located at:

http://www.zebra.org/.

1.6 Mailing List

There is a mailing list for discussions about Quagga. If you have anycomments or suggestions to Quagga, please subscribe to:

http://lists.quagga.net/mailman/listinfo/quagga-users.

The Quagga site has further information onthe available mailing lists, see:

http://www.quagga.net/lists.php

1.7 Bug Reports

If you think you have found a bug, please send a bug report to:

http://bugzilla.quagga.net

When you send a bug report, please be careful about the points below.

Please note what kind of OS you are using. If you use the IPv6 stackplease note that as well.
Please show us the results of netstat -rn and ifconfig -a.Information from zebra’s VTY command show ip route will also behelpful.
Please send your configuration file with the report. If you specifyarguments to the configure script please note that too.

Bug reports are very important for us to improve the quality of Quagga.Quagga is still in the development stage, but please don’t hesitate tosend a bug report to http://bugzilla.quagga.net.

2 Installation

There are three steps for installing the software: configuration,compilation, and installation.

The easiest way to get Quagga running is to issue the followingcommands:

% configure
% make
% make install

2.1 Configure the Software

2.1.1 The Configure script and its options

Quagga has an excellent configure script which automatically detects mosthost configurations. There are several additional configure options you canuse to turn off IPv6 support, to disable the compilation of specificdaemons, and to enable SNMP support.

--disable-ipv6: Turn off IPv6 related features and daemons. Quagga configure scriptautomatically detects IPv6 stack. But sometimes you might want todisable IPv6 support of Quagga.
--disable-zebra: Do not build zebra daemon.
--disable-ripd: Do not build ripd.
--disable-ripngd: Do not build ripngd.
--disable-ospfd: Do not build ospfd.
--disable-ospf6d: Do not build ospf6d.
--disable-bgpd: Do not build bgpd.
--disable-bgp-announce: Make bgpd which does not make bgp announcements at all. Thisfeature is good for using bgpd as a BGP announcement listener.
--enable-netlink: Force to enable GNU/Linux netlink interface. Quagga configurescript detects netlink interface by checking a header file. When the headerfile does not match to the current running kernel, configure script willnot turn on netlink support.
--enable-snmp: Enable SNMP support. By default, SNMP support is disabled.
--disable-opaque-lsa: Disable support for Opaque LSAs (RFC2370) in ospfd.
--disable-ospfapi: Disable support for OSPF-API, an API to interface directly with ospfd.OSPF-API is enabled if –enable-opaque-lsa is set.
--disable-ospfclient: Disable building of the example OSPF-API client.
--disable-ospf-te: Disable support for OSPF Traffic Engineering Extension (RFC3630) thisrequires support for Opaque LSAs.
--disable-ospf-ri: Disable support for OSPF Router Information (RFC4970 & RFC5088) thisrequires support for Opaque LSAs and Traffic Engineering.
--enable-isisd: Build isisd.
--enable-isis-topology: Enable IS-IS topology generator.
--enable-isis-te: Enable Traffic Engineering Extension for ISIS (RFC5305)
--enable-multipath=ARG: Enable support for Equal Cost Multipath. ARG is the maximum numberof ECMP paths to allow, set to 0 to allow unlimited number of paths.
--disable-rtadv: Disable support IPV6 router advertisement in zebra.
--enable-gcc-rdynamic: Pass the -rdynamic option to the linker driver. This is in mostcases neccessary for getting usable backtraces. This option defaults to onif the compiler is detected as gcc, but giving an explicit enable/disable issuggested.
--enable-backtrace: Controls backtrace support for the crash handlers. This is autodetected bydefault. Using the switch will enforce the requested behaviour, failing withan error if support is requested but not available. On BSD systems, thisneeds libexecinfo, while on glibc support for this is part of libc itself.

You may specify any combination of the above options to the configurescript. By default, the executables are placed in /usr/local/sbin and the configuration files in /usr/local/etc. The /usr/local/installation prefix and other directories may be changed using the following options to the configuration script.

--prefix=prefix: Install architecture-independent files in prefix [/usr/local].
--sysconfdir=dir: Look for configuration files in dir [prefix/etc]. Notethat sample configuration files will be installed here.
--localstatedir=dir: Configure zebra to use dir for local state files, suchas pid files and unix sockets.

% ./configure --disable-ipv6

This command will configure zebra and the routing daemons.

2.1.2 Least-Privilege support

Additionally, you may configure zebra to drop its elevated privilegesshortly after startup and switch to another user. The configure script willautomatically try to configure this support. There are three configureoptions to control the behaviour of Quagga daemons.

--enable-user=user: Switch to user ARG shortly after startup, and run as user ARGin normal operation.
--enable-group=group: Switch real and effective group to group shortly afterstartup.
--enable-vty-group=group: Create Unix Vty sockets (for use with vtysh) with group owndership set togroup. This allows one to create a seperate group which isrestricted to accessing only the Vty sockets, hence allowing one todelegate this group to individual users, or to run vtysh setgid tothis group.

The default user and group which will be configured is ’quagga’ if no useror group is specified. Note that this user or group requires write access tothe local state directory (see –localstatedir) and requires at least readaccess, and write access if you wish to allow daemons to write out theirconfiguration, to the configuration directory (see –sysconfdir).

On systems which have the ’libcap’ capabilities manipulation library(currently only linux), the quagga system will retain only minimalcapabilities required, further it will only raise these capabilities forbrief periods. On systems without libcap, quagga will run as the userspecified and only raise its uid back to uid 0 for brief periods.

2.1.3 Linux Notes

There are several options available only to GNU/Linux systems:¹. Ifyou use GNU/Linux, make sure that the current kernel configuration iswhat you want. Quagga will run with any kernel configuration but somerecommendations do exist.

CONFIG_NETLINK: Kernel/User netlink socket. This is a brand new feature which enables anadvanced interface between the Linux kernel and zebra (see Kernel Interface).
CONFIG_RTNETLINK: Routing messages.This makes it possible to receive netlink routing messages. If youspecify this option, zebra can detect routing informationupdates directly from the kernel (see Kernel Interface).
CONFIG_IP_MULTICAST: IP: multicasting. This option should be specified when you use ripd (see RIP) orospfd (see OSPFv2) because these protocols use multicast.

IPv6 support has been added in GNU/Linux kernel version 2.2. If youtry to use the Quagga IPv6 feature on a GNU/Linux kernel, pleasemake sure the following libraries have been installed. Please note thatthese libraries will not be needed when you uses GNU C library 2.1or upper.

inet6-apps: The inet6-apps package includes basic IPv6 related libraries suchas inet_ntop and inet_pton. Some basic IPv6 programs suchas ping, ftp, and inetd are alsoincluded. The inet-apps can be found atftp://ftp.inner.net/pub/ipv6/.
net-tools: The net-tools package provides an IPv6 enabled interface androuting utility. It contains ifconfig, route,netstat, and other tools. net-tools may be found athttp://www.tazenda.demon.co.uk/phil/net-tools/.

2.2 Build the Software

After configuring the software, you will need to compile it for yoursystem. Simply issue the command make in the root of the sourcedirectory and the software will be compiled. If you have *any* problemsat this stage, be certain to send a bug report See Bug Reports.

% ./configure
.
.
.
./configure output
.
.
.
% make

2.3 Install the Software

Installing the software to your system consists of copying the compiledprograms and supporting files to a standard location. After theinstallation process has completed, these files have been copiedfrom your work directory to /usr/local/bin, and /usr/local/etc.

To install the Quagga suite, issue the following command at your shellprompt: make install.

%
% make install
%

Quagga daemons have their own terminal interface or VTY. Afterinstallation, you have to setup each beast’s port number to connect tothem. Please add the following entries to /etc/services.

zebrasrv      2600/tcp		  # zebra service
zebra         2601/tcp		  # zebra vty
ripd          2602/tcp		  # RIPd vty
ripngd        2603/tcp		  # RIPngd vty
ospfd         2604/tcp		  # OSPFd vty
bgpd          2605/tcp		  # BGPd vty
ospf6d        2606/tcp		  # OSPF6d vty
ospfapi       2607/tcp		  # ospfapi
isisd         2608/tcp		  # ISISd vty
pimd          2611/tcp		  # PIMd vty
nhrpd         2612/tcp		  # nhrpd vty

If you use a FreeBSD newer than 2.2.8, the above entries are alreadyadded to /etc/services so there is no need to add it. If youspecify a port number when starting the daemon, these entries may not beneeded.

You may need to make changes to the config files in/etc/quagga/*.conf. See Config Commands.

3 Basic commands

There are five routing daemons in use, and there is one manager daemon.These daemons may be located on separate machines from the managerdaemon. Each of these daemons will listen on a particular port forincoming VTY connections. The routing daemons are:

ripd, ripngd, ospfd, ospf6d, bgpd
zebra

The following sections discuss commands common to all the routingdaemons.

3.1 Config Commands

In a config file, you can write the debugging options, a vty’s password,routing daemon configurations, a log file name, and so forth. Thisinformation forms the initial command set for a routing beast as it isstarting.

Config files are generally found in:

/etc/quagga/*.conf

Each of the daemons has its ownconfig file. For example, zebra’s default config file name is:

/etc/quagga/zebra.conf

The daemon name plus .conf is the default config file name. Youcan specify a config file using the -f or --config-fileoptions when starting the daemon.

3.1.1 Basic Config Commands

Command: hostname hostname: Set hostname of the router.

Command: password password: Set password for vty interface. If there is no password, a vty won’taccept connections.

Command: enable password password: Set enable password.

Command: log trap level
Command: no log trap: These commands are deprecated and are present only for historical compatibility.The log trap command sets the current logging level for all enabledlogging destinations, and it sets the default for all future logging commandsthat do not specify a level. The normal defaultlogging level is debugging. The no form of the command resetsthe default level for future logging commands to debugging, but it doesnot change the logging level of existing logging destinations.

Command: log stdout
Command: log stdout level
Command: no log stdout: Enable logging output to stdout. If the optional second argument specifying thelogging level is not present, the default logging level (typically debugging,but can be changed using the deprecated log trap command) will be used.The no form of the command disables logging to stdout.The level argument must have one of these values: emergencies, alerts, critical, errors, warnings, notifications, informational, or debugging. Note that the existing code logs its most important messageswith severity errors.

Command: log file filename

Command: log file filename level

Command: no log file

If you want to log into a file, please specify filename asin this example:

log file /var/log/quagga/bgpd.log informational

If the optional second argument specifying thelogging level is not present, the default logging level (typically debugging,but can be changed using the deprecated log trap command) will be used.The no form of the command disables logging to a file.

Note: if you do not configure any file logging, and a daemon crashes dueto a signal or an assertion failure, it will attempt to save the crashinformation in a file named /var/tmp/quagga.<daemon name>.crashlog.For security reasons, this will not happen if the file exists already, soit is important to delete the file after reporting the crash information.

Command: log syslog
Command: log syslog level
Command: no log syslog: Enable logging output to syslog.If the optional second argument specifying thelogging level is not present, the default logging level (typically debugging,but can be changed using the deprecated log trap command) will be used.The no form of the command disables logging to syslog.

Command: log monitor
Command: log monitor level
Command: no log monitor: Enable logging output to vty terminals that have enabled loggingusing the terminal monitor command.By default, monitor logging is enabled at the debugging level, but thiscommand (or the deprecated log trap command) can be used to change the monitor logging level.If the optional second argument specifying thelogging level is not present, the default logging level (typically debugging,but can be changed using the deprecated log trap command) will be used.The no form of the command disables logging to terminal monitors.

Command: log facility facility
Command: no log facility: This command changes the facility used in syslog messages. The defaultfacility is daemon. The no form of the command resetsthe facility to the default daemon facility.

Command: log record-priority
Command: no log record-priority: To include the severity in all messages logged to a file, to stdout, or toa terminal monitor (i.e. anything except syslog),use the log record-priority global configuration command.To disable this option, use the no form of the command. By default,the severity level is not included in logged messages. Note: someversions of syslogd (including Solaris) can be configured to includethe facility and level in the messages emitted.

Command: log timestamp precision <0-6>

Command: no log timestamp precision

This command sets the precision of log message timestamps to thegiven number of digits after the decimal point. Currently,the value must be in the range 0 to 6 (i.e. the maximum precisionis microseconds).To restore the default behavior (1-second accuracy), use theno form of the command, or set the precision explicitly to 0.

log timestamp precision 3

In this example, the precision is set to provide timestamps withmillisecond accuracy.

Command: log commands: This command enables the logging of all commands typed by a user toall enabled log destinations. The note that logging includes fullcommand lines, including passwords. Once set, command logging can onlybe turned off by restarting the daemon.

Command: service password-encryption: Encrypt password.

Command: service advanced-vty: Enable advanced mode VTY.

Command: service terminal-length <0-512>: Set system wide line configuration. This configuration command appliesto all VTY interfaces.

Command: line vty: Enter vty configuration mode.

Command: banner motd default: Set default motd string.

Command: no banner motd: No motd banner string will be printed.

Line Command: exec-timeout minute
Line Command: exec-timeout minute second: Set VTY connection timeout value. When only one argument is specifiedit is used for timeout value in minutes. Optional second argument isused for timeout value in seconds. Default timeout value is 10 minutes.When timeout value is zero, it means no timeout.

Line Command: no exec-timeout: Do not perform timeout at all. This command is as same asexec-timeout 0 0.

Line Command: access-class access-list: Restrict vty connections with an access list.

3.1.2 Sample Config File

Below is a sample configuration file for the zebra daemon.

!
! Zebra configuration file
!
hostname Router
password zebra
enable password zebra
!
log stdout
!
!

’!’ and ’#’ are comment characters. If the first character of the wordis one of the comment characters then from the rest of the line forwardwill be ignored as a comment.

password zebra!password

If a comment character is not the first character of the word, it’s anormal character. So in the above example ’!’ will not be regarded as acomment and the password is set to ’zebra!password’.

3.2 Terminal Mode Commands

Command: write terminal: Displays the current configuration to the vty interface.

Command: write file: Write current configuration to configuration file.

Command: configure terminal: Change to configuration mode. This command is the first step toconfiguration.

Command: terminal length <0-512>: Set terminal display length to <0-512>. If length is 0, nodisplay control is performed.

Command: who: Show a list of currently connected vty sessions.

Command: list: List all available commands.

Command: show version: Show the current version of Quagga and its build host information.

Command: show logging: Shows the current configuration of the logging system. This includesthe status of all logging destinations.

Command: logmsg level message: Send a message to all logging destinations that are enabled for messagesof the given severity.

3.3 Common Invocation Options

These options apply to all Quagga daemons.

‘-d’

‘--daemon’

Runs in daemon mode.

‘-f file’

‘--config_file=file’

Set configuration file name.

‘-h’

‘--help’

Display this help and exit.

‘-i file’

‘--pid_file=file’

Upon startup the process identifier of the daemon is written to a file,typically in /var/run. This file can be used by the init systemto implement commands such as …/init.d/zebra status,…/init.d/zebra restart or …/init.d/zebrastop.

The file name is an run-time option rather than a configure-time optionso that multiple routing daemons can be run simultaneously. This isuseful when using Quagga to implement a routing looking glass. Onemachine can be used to collect differing routing views from differingpoints in the network.

‘-A address’

‘--vty_addr=address’

Set the VTY local address to bind to. If set, the VTY socket will onlybe bound to this address.

‘-P port’

‘--vty_port=port’

Set the VTY TCP port number. If set to 0 then the TCP VTY sockets will notbe opened.

‘-u user’

‘--vty_addr=user’

Set the user and group to run as.

‘-v’

‘--version’

Print program version.

3.4 Virtual Terminal Interfaces

VTY – Virtual Terminal [aka TeletYpe] Interface is a command lineinterface (CLI) for user interaction with the routing daemon.

3.4.1 VTY Overview

VTY stands for Virtual TeletYpe interface. It means you can connect tothe daemon via the telnet protocol.

To enable a VTY interface, you have to setup a VTY password. If thereis no VTY password, one cannot connect to the VTY interface at all.

% telnet localhost 2601
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

Hello, this is Quagga (version 1.2.0)
Copyright © 1999-2005 Kunihiro Ishiguro, et al.

User Access Verification

Password: XXXXX
Router> ?
  enable            Turn on privileged commands
  exit              Exit current mode and down to previous mode
  help              Description of the interactive help system
  list              Print command list
  show              Show running system information
  who               Display who is on a vty
Router> enable
Password: XXXXX
Router# configure terminal
Router(config)# interface eth0
Router(config-if)# ip address 10.0.0.1/8
Router(config-if)# ^Z
Router#

’?’ is very useful for looking up commands.

3.4.2 VTY Modes

There are three basic VTY modes:

There are commands that may be restricted to specific VTY modes.

3.4.2.1 VTY View Mode

This mode is for read-only access to the CLI. One may exit the mode byleaving the system, or by entering enable mode.

3.4.2.2 VTY Enable Mode

This mode is for read-write access to the CLI. One may exit the mode byleaving the system, or by escaping to view mode.

3.4.2.3 VTY Other Modes

This page is for describing other modes.

3.4.3 VTY CLI Commands

Commands that you may use at the command-line are described in the followingthree subsubsections.

3.4.3.1 CLI Movement Commands

These commands are used for moving the CLI cursor. The C charactermeans press the Control Key.

C-f
RIGHT: Move forward one character.
C-b
LEFT: Move backward one character.
M-f: Move forward one word.
M-b: Move backward one word.
C-a: Move to the beginning of the line.
C-e: Move to the end of the line.

3.4.3.2 CLI Editing Commands

These commands are used for editing text on a line. The Ccharacter means press the Control Key.

C-h
DEL: Delete the character before point.
C-d: Delete the character after point.
M-d: Forward kill word.
C-w: Backward kill word.
C-k: Kill to the end of the line.
C-u: Kill line from the beginning, erasing input.
C-t: Transpose character.
C-v: Interpret following character literally. Do not treat it specially.This can be used to, e.g., type in a literal ? rather than dohelp completion.

3.4.3.3 CLI Advanced Commands

There are several additional CLI commands for command line completions,insta-help, and VTY session management.

C-c

Interrupt current input and moves to the next line.

C-z

End current configuration session and move to top node.

C-n

DOWN

Move down to next line in the history buffer.

C-p

UP

Move up to previous line in the history buffer.

TAB

Use command line completion by typing TAB.

?

You can use command line help by typing help at the beginning ofthe line. Typing ? at any point in the line will show possiblecompletions.

To enter an actual ? character rather show completions, e.g. toenter into a regexp, use C-v ?.

4 Zebra

zebra is an IP routing manager. It provides kernel routingtable updates, interface lookups, and redistribution of routes betweendifferent routing protocols.

4.1 Invoking zebra

Besides the common invocation options (see Common Invocation Options), thezebra specific invocation options are listed below.

‘-b’
‘--batch’: Runs in batch mode. zebra parses configuration file and terminatesimmediately.
‘-k’
‘--keep_kernel’: When zebra starts up, don’t delete old self inserted routes.
‘-r’
‘--retain’: When program terminates, retain routes added by zebra.

4.2 Interface Commands

4.2.1 Standard Commands

Command: interface ifname

Interface Command: shutdown
Interface Command: no shutdown: Up or down the current interface.

Interface Command: ip address address/prefix
Interface Command: ipv6 address address/prefix
Interface Command: no ip address address/prefix
Interface Command: no ipv6 address address/prefix: Set the IPv4 or IPv6 address/prefix for the interface.

Interface Command: ip address address/prefix secondary
Interface Command: no ip address address/prefix secondary: Set the secondary flag for this address. This causes ospfd to not treat theaddress as a distinct subnet.

Interface Command: description description ...: Set description for the interface.

Interface Command: multicast
Interface Command: no multicast: Enable or disables multicast flag for the interface.

Interface Command: bandwidth <1-10000000>
Interface Command: no bandwidth <1-10000000>: Set bandwidth value of the interface in kilobits/sec. This is forcalculating OSPF cost. This command does not affect the actual deviceconfiguration.

Interface Command: link-detect
Interface Command: no link-detect: Enable/disable link-detect on platforms which support this. Currentlyonly Linux and Solaris, and only where network interface drivers support reportinglink-state via the IFF_RUNNING flag.

4.2.2 Link Parameters Commands

Interface Command: link-params
Interface Command: no link-param: Enter into the link parameters sub node. At least ’enable’ must be set to activate the link parameters,and consequently Traffic Engineering on this interface. MPLS-TE must be enable at the OSPF (OSPF Traffic Engineering)or ISIS (ISIS Traffic Engineering) router level in complement to this.Disable link parameters for this interface.

Under link parameter statement, the following commands set the different TE values:

link-params: enable: Enable link parameters for this interface.

link-params: metric <0-4294967295>

link-params: max-bw bandwidth

link-params: max-rsv-bw bandwidth

link-params: unrsv-bw <0-7> bandwidth

link-params: admin-grp bandwidth

These commands specifies the Traffic Engineering parameters of the interface in conformity to RFC3630 (OSPF)or RFC5305 (ISIS).There are respectively the TE Metric (different from the OSPF or ISIS metric), Maximum Bandwidth (interface speedby default), Maximum Reservable Bandwidth, Unreserved Bandwidth for each 0-7 priority and Admin Group (ISIS) orResource Class/Color (OSPF).

Note that bandwidth are specified in IEEE floating point format and express in Bytes/second.

link-param: delay <0-16777215> [min <0-16777215> | max <0-16777215>]

link-param: delay-variation <0-16777215>

link-param: packet-loss percentage

link-param: res-bw bandwidth

link-param: ava-bw bandwidth

link-param: use-bw bandwidth

These command specifies additionnal Traffic Engineering parameters of the interface in conformity todraft-ietf-ospf-te-metrics-extension-05.txt and draft-ietf-isis-te-metrics-extension-03.txt. There arerespectively the delay, jitter, loss, available bandwidth, reservable bandwidth and utilized bandwidth.

Note that bandwidth are specified in IEEE floating point format and express in Bytes/second.Delays and delay variation are express in micro-second (Âµs). Loss is specified in percentage rangingfrom 0 to 50.331642% by step of 0.000003.

link-param: neighbor <A.B.C.D> as <0-65535>
link-param: no neighbor: Specifies the remote ASBR IP address and Autonomous System (AS) number for InterASv2 link in OSPF (RFC5392).Note that this option is not yet supported for ISIS (RFC5316).

4.3 Static Route Commands

Static routing is a very fundamental feature of routing technology. Itdefines static prefix and gateway.

Command: ip route network gateway

network is destination prefix with format of A.B.C.D/M.gateway is gateway for the prefix. When gateway isA.B.C.D format. It is taken as a IPv4 address gateway. Otherwise itis treated as an interface name. If the interface name is null0 thenzebra installs a blackhole route.

ip route 10.0.0.0/8 10.0.0.2
ip route 10.0.0.0/8 ppp0
ip route 10.0.0.0/8 null0

First example defines 10.0.0.0/8 static route with gateway 10.0.0.2.Second one defines the same prefix but with gateway to interface ppp0. Thethird install a blackhole route.

Command: ip route network netmask gateway

This is alternate version of above command. When network isA.B.C.D format, user must define netmask value with A.B.C.Dformat. gateway is same option as above command

ip route 10.0.0.0 255.0.0.0 10.0.0.2
ip route 10.0.0.0 255.0.0.0 ppp0
ip route 10.0.0.0 255.0.0.0 null0

These statements are equivalent to those in the previous example.

Command: ip route network gateway distance: Installs the route with the specified distance.

Multiple nexthop static route

ip route 10.0.0.1/32 10.0.0.2
ip route 10.0.0.1/32 10.0.0.3
ip route 10.0.0.1/32 eth0

If there is no route to 10.0.0.2 and 10.0.0.3, and interface eth0is reachable, then the last route is installed into the kernel.

If zebra has been compiled with multipath support, and both 10.0.0.2 and10.0.0.3 are reachable, zebra will install a multipath route via bothnexthops, if the platform supports this.

zebra> show ip route
S>  10.0.0.1/32 [1/0] via 10.0.0.2 inactive
                      via 10.0.0.3 inactive
  *                   is directly connected, eth0

ip route 10.0.0.0/8 10.0.0.2
ip route 10.0.0.0/8 10.0.0.3
ip route 10.0.0.0/8 null0 255

This will install a multihop route via the specified next-hops if they arereachable, as well as a high-metric blackhole route, which can be useful toprevent traffic destined for a prefix to match less-specific routes (egdefault) should the specified gateways not be reachable. Eg:

zebra> show ip route 10.0.0.0/8
Routing entry for 10.0.0.0/8
  Known via "static", distance 1, metric 0
    10.0.0.2 inactive
    10.0.0.3 inactive

Routing entry for 10.0.0.0/8
  Known via "static", distance 255, metric 0
    directly connected, Null0

Command: ipv6 route network gateway
Command: ipv6 route network gateway distance: These behave similarly to their ipv4 counterparts.

Command: table tableno: Select the primary kernel routing table to be used. This only worksfor kernels supporting multiple routing tables (like GNU/Linux 2.2.xand later). After setting tableno with this command,static routes defined after this are added to the specified table.

4.4 Multicast RIB Commands

The Multicast RIB provides a separate table of unicast destinations whichis used for Multicast Reverse Path Forwarding decisions. It is used witha multicast source’s IP address, hence contains not multicast groupaddresses but unicast addresses.

This table is fully separate from the default unicast table. However,RPF lookup can include the unicast table.

WARNING: RPF lookup results are non-responsive in this version of Quagga,i.e. multicast routing does not actively react to changes in underlyingunicast topology!

Command: ip multicast rpf-lookup-mode mode

Command: no ip multicast rpf-lookup-mode [mode]

mode sets the method used to perform RPF lookups. Supported modes:

‘urib-only’: Performs the lookup on the Unicast RIB. The Multicast RIB is never used.
‘mrib-only’: Performs the lookup on the Multicast RIB. The Unicast RIB is never used.
‘mrib-then-urib’: Tries to perform the lookup on the Multicast RIB. If any route is found,that route is used. Otherwise, the Unicast RIB is tried.
‘lower-distance’: Performs a lookup on the Multicast RIB and Unicast RIB each. The resultwith the lower administrative distance is used; if they’re equal, theMulticast RIB takes precedence.
‘longer-prefix’: Performs a lookup on the Multicast RIB and Unicast RIB each. The resultwith the longer prefix length is used; if they’re equal, theMulticast RIB takes precedence.

The mrib-then-urib setting is the default behavior if nothing isconfigured. If this is the desired behavior, it should be explicitlyconfigured to make the configuration immune against possible changes inwhat the default behavior is.

WARNING: Unreachable routes do not receive special treatment and do notcause fallback to a second lookup.

Command: show ip rpf addr

Performs a Multicast RPF lookup, as configured withip multicast rpf-lookup-mode mode. addr specifiesthe multicast source address to look up.

> show ip rpf 192.0.2.1
Routing entry for 192.0.2.0/24 using Unicast RIB
  Known via "kernel", distance 0, metric 0, best
  * 198.51.100.1, via eth0

Indicates that a multicast source lookup for 192.0.2.1 would use anUnicast RIB entry for 192.0.2.0/24 with a gateway of 198.51.100.1.

Command: show ip rpf: Prints the entire Multicast RIB. Note that this is independent of theconfigured RPF lookup mode, the Multicast RIB may be printed yet notused at all.

Command: ip mroute prefix nexthop [distance]
Command: no ip mroute prefix nexthop [distance]: Adds a static route entry to the Multicast RIB. This performs exactly asthe ip route command, except that it inserts the route in theMulticast RIB instead of the Unicast RIB.

4.5 zebra Route Filtering

Zebra supports prefix-list and route-map to matchroutes received from other quagga components. Thepermit/deny facilities provided by these commandscan be used to filter which routes zebra will install in the kernel.

Command: ip protocol protocol route-map routemap: Apply a route-map filter to routes for the specified protocol. protocolcan be any or one ofsystem,kernel,connected,static,rip,ripng,ospf,ospf6,isis,bgp,hsls.

Route Map: set src address: Within a route-map, set the preferred source address for matching routeswhen installing in the kernel.

The following creates a prefix-list that matches all addresses, a route-mapthat sets the preferred source address, and applies the route-map to allrip routes.

ip prefix-list ANY permit 0.0.0.0/0 le 32
route-map RM1 permit 10
     match ip address prefix-list ANY
     set src 10.0.0.1

ip protocol rip route-map RM1

4.6 zebra FIB push interface

Zebra supports a ’FIB push’ interface that allows an externalcomponent to learn the forwarding information computed by the Quaggarouting suite.

In Quagga, the Routing Information Base (RIB) resides insidezebra. Routing protocols communicate their best routes to zebra, andzebra computes the best route across protocols for each prefix. Thislatter information makes up the Forwarding Information Base(FIB). Zebra feeds the FIB to the kernel, which allows the IP stack inthe kernel to forward packets according to the routes computed byQuagga. The kernel FIB is updated in an OS-specific way. For example,the netlink interface is used on Linux, and route sockets areused on FreeBSD.

The FIB push interface aims to provide a cross-platform mechanism tosupport scenarios where the router has a forwarding path that isdistinct from the kernel, commonly a hardware-based fast path. Inthese cases, the FIB needs to be maintained reliably in the fast pathas well. We refer to the component that programs the forwarding plane(directly or indirectly) as the Forwarding Plane Manager or FPM.

The FIB push interface comprises of a TCP connection between zebra andthe FPM. The connection is initiated by zebra – that is, the FPM actsas the TCP server.

The relevant zebra code kicks in when zebra is configured with the--enable-fpm flag. Zebra periodically attempts to connect tothe well-known FPM port. Once the connection is up, zebra startssending messages containing routes over the socket to the FPM. Zebrasends a complete copy of the forwarding table to the FPM, includingroutes that it may have picked up from the kernel. The existinginteraction of zebra with the kernel remains unchanged – that is, thekernel continues to receive FIB updates as before.

The encapsulation header for the messages exchanged with the FPM isdefined by the file fpm/fpm.h in the quagga tree. The routesthemselves are encoded in netlink or protobuf format, with netlinkbeing the default.

Protobuf is one of a number of new serialization formats wherein themessage schema is expressed in a purpose-built language. Code forencoding/decoding to/from the wire format is generated from theschema. Protobuf messages can be extended easily while maintainingbackward-compatibility with older code. Protobuf has the followingadvantages over netlink:

Code for serialization/deserialization is generatedautomatically. This reduces the likelihood of bugs, allows third-partyprograms to be integrated quickly, and makes it easy to add fields.
The message format is not tied to an OS (Linux), and can be evolvedindependently.

As mentioned before, zebra encodes routes sent to the FPM in netlinkformat by default. The format can be controlled via the--fpm_format command-line option to zebra, which currentlytakes the values netlink and protobuf.

The zebra FPM interface uses replace semantics. That is, if a ’routeadd’ message for a prefix is followed by another ’route add’ message,the information in the second message is complete by itself, andreplaces the information sent in the first message.

If the connection to the FPM goes down for some reason, zebra sendsthe FPM a complete copy of the forwarding table(s) when it reconnects.

4.7 zebra Terminal Mode Commands

Command: show ip route

Display current routes which zebra holds in its database.

Router# show ip route
Codes: K - kernel route, C - connected, S - static, R - RIP,
       B - BGP * - FIB route.

K* 0.0.0.0/0              203.181.89.241
S  0.0.0.0/0              203.181.89.1
C* 127.0.0.0/8            lo
C* 203.181.89.240/28      eth0

Command: show ipv6 route

Command: show interface

Command: show ip prefix-list [name]

Command: show route-map [name]

Command: show ip protocol

Command: show ipforward: Display whether the host’s IP forwarding function is enabled or not.Almost any UNIX kernel can be configured with IP forwarding disabled.If so, the box can’t work as a router.

Command: show ipv6forward: Display whether the host’s IP v6 forwarding is enabled or not.

Command: show zebra fpm stats: Display statistics related to the zebra code that interacts with theoptional Forwarding Plane Manager (FPM) component.

Command: clear zebra fpm stats: Reset statistics related to the zebra code that interacts with theoptional Forwarding Plane Manager (FPM) component.

5 RIP

RIP – Routing Information Protocol is widely deployed interior gatewayprotocol. RIP was developed in the 1970s at Xerox Labs as part of theXNS routing protocol. RIP is a distance-vector protocol and isbased on the Bellman-Ford algorithms. As a distance-vectorprotocol, RIP router send updates to its neighbors periodically, thusallowing the convergence to a known topology. In each update, thedistance to any given network will be broadcasted to its neighboringrouter.

ripd supports RIP version 2 as described in RFC2453 and RIPversion 1 as described in RFC1058.

5.1 Starting and Stopping ripd

The default configuration file name of ripd’s isripd.conf. When invocation ripd searches directory/etc/quagga. If ripd.conf is not there nextsearch current directory.

RIP uses UDP port 520 to send and receive RIP packets. So the user must havethe capability to bind the port, generally this means that the user musthave superuser privileges. RIP protocol requires interface informationmaintained by zebra daemon. So running zebrais mandatory to run ripd. Thus minimum sequence for runningRIP is like below:

# zebra -d
# ripd -d

Please note that zebra must be invoked before ripd.

To stop ripd. Please use kill `cat/var/run/ripd.pid`. Certain signals have special meaningss to ripd.

‘SIGHUP’: Reload configuration file ripd.conf. All configurations arereseted. All routes learned so far are cleared and removed from routingtable.
‘SIGUSR1’: Rotate ripd logfile.
‘SIGINT’
‘SIGTERM’: ripd sweeps all installed RIP routes then terminates properly.

ripd invocation options. Common options that can be specified(see Common Invocation Options).

‘-r’
‘--retain’: When the program terminates, retain routes added by ripd.

5.1.1 RIP netmask

The netmask features of ripd support both version 1 and version 2 ofRIP. Version 1 of RIP originally contained no netmask information. InRIP version 1, network classes were originally used to determine thesize of the netmask. Class A networks use 8 bits of mask, Class Bnetworks use 16 bits of masks, while Class C networks use 24 bits ofmask. Today, the most widely used method of a network mask is assignedto the packet on the basis of the interface that received the packet.Version 2 of RIP supports a variable length subnet mask (VLSM). Byextending the subnet mask, the mask can be divided and reused. Eachsubnet can be used for different purposes such as large to middle sizeLANs and WAN links. Quagga ripd does not support the non-sequentialnetmasks that are included in RIP Version 2.

In a case of similar information with the same prefix and metric, theold information will be suppressed. Ripd does not currently supportequal cost multipath routing.

5.2 RIP Configuration

Command: router rip: The router rip command is necessary to enable RIP. To disableRIP, use the no router rip command. RIP must be enabled beforecarrying out any of the RIP commands.

Command: no router rip: Disable RIP.

RIP Command: network network

RIP Command: no network network

Set the RIP enable interface by network. The interfaces whichhave addresses matching with network are enabled.

This group of commands either enables or disables RIP interfaces betweencertain numbers of a specified network address. For example, if thenetwork for 10.0.0.0/24 is RIP enabled, this would result in all theaddresses from 10.0.0.0 to 10.0.0.255 being enabled for RIP. The nonetwork command will disable RIP for the specified network.

RIP Command: network ifname
RIP Command: no network ifname: Set a RIP enabled interface by ifname. Both the sending andreceiving of RIP packets will be enabled on the port specified in thenetwork ifname command. The no network ifname command will disableRIP on the specified interface.

RIP Command: neighbor a.b.c.d
RIP Command: no neighbor a.b.c.d: Specify RIP neighbor. When a neighbor doesn’t understand multicast,this command is used to specify neighbors. In some cases, not allrouters will be able to understand multicasting, where packets are sentto a network or a group of addresses. In a situation where a neighborcannot process multicast packets, it is necessary to establish a directlink between routers. The neighbor command allows the networkadministrator to specify a router as a RIP neighbor. The noneighbor a.b.c.d command will disable the RIP neighbor.

Below is very simple RIP configuration. Interface eth0 andinterface which address match to 10.0.0.0/8 are RIP enabled.

!
router rip
 network 10.0.0.0/8
 network eth0
!

Passive interface

RIP command: passive-interface (IFNAME|default)

RIP command: no passive-interface IFNAME

This command sets the specified interface to passive mode. On passive modeinterface, all receiving packets are processed as normal and ripd doesnot send either multicast or unicast RIP packets except to RIP neighborsspecified with neighbor command. The interface may be specifiedas default to make ripd default to passive on all interfaces.

The default is to be passive on all interfaces.

RIP split-horizon

Interface command: ip split-horizon
Interface command: no ip split-horizon: Control split-horizon on the interface. Default is ipsplit-horizon. If you don’t perform split-horizon on the interface,please specify no ip split-horizon.

5.3 RIP Version Control

RIP can be configured to send either Version 1 or Version 2 packets.The default is to send RIPv2 while accepting both RIPv1 and RIPv2 (andreplying with packets of the appropriate version for REQUESTS /triggered updates). The version to receive and send can be specifiedglobally, and further overriden on a per-interface basis if needs befor send and receive seperately (see below).

It is important to note that RIPv1 can not be authenticated. Further,if RIPv1 is enabled then RIP will reply to REQUEST packets, sending thestate of its RIP routing table to any remote routers that ask ondemand. For a more detailed discussion on the security implications ofRIPv1 see RIP Authentication.

RIP Command: version version

Set RIP version to accept for reads and send. versioncan be either ‘1” or ‘2”.

Disabling RIPv1 by specifying version 2 is STRONGLY encouraged,See RIP Authentication. This may become the default in a futurerelease.

Default: Send Version 2, and accept either version.

RIP Command: no version: Reset the global version setting back to the default.

Interface command: ip rip send version version

version can be ‘1’, ‘2’ or ‘1 2’.

This interface command overrides the global rip version setting, andselects which version of RIP to send packets with, for this interfacespecifically. Choice of RIP Version 1, RIP Version 2, or both versions. In the latter case, where ‘1 2’ is specified, packets will be bothbroadcast and multicast.

Default: Send packets according to the global version (version 2)

Interface command: ip rip receive version version

version can be ‘1’, ‘2’ or ‘1 2’.

This interface command overrides the global rip version setting, andselects which versions of RIP packets will be accepted on thisinterface. Choice of RIP Version 1, RIP Version 2, or both.

Default: Accept packets according to the global setting (both 1 and 2).

5.4 How to Announce RIP route

RIP command: redistribute kernel
RIP command: redistribute kernel metric <0-16>
RIP command: redistribute kernel route-map route-map
RIP command: no redistribute kernel: redistribute kernel redistributes routing information fromkernel route entries into the RIP tables. no redistribute kerneldisables the routes.

RIP command: redistribute static
RIP command: redistribute static metric <0-16>
RIP command: redistribute static route-map route-map
RIP command: no redistribute static: redistribute static redistributes routing information fromstatic route entries into the RIP tables. no redistribute staticdisables the routes.

RIP command: redistribute connected
RIP command: redistribute connected metric <0-16>
RIP command: redistribute connected route-map route-map
RIP command: no redistribute connected: Redistribute connected routes into the RIP tables. noredistribute connected disables the connected routes in the RIP tables.This command redistribute connected of the interface which RIP disabled.The connected route on RIP enabled interface is announced by default.

RIP command: redistribute ospf
RIP command: redistribute ospf metric <0-16>
RIP command: redistribute ospf route-map route-map
RIP command: no redistribute ospf: redistribute ospf redistributes routing information fromospf route entries into the RIP tables. no redistribute ospfdisables the routes.

RIP command: redistribute bgp
RIP command: redistribute bgp metric <0-16>
RIP command: redistribute bgp route-map route-map
RIP command: no redistribute bgp: redistribute bgp redistributes routing information frombgp route entries into the RIP tables. no redistribute bgpdisables the routes.

If you want to specify RIP only static routes:

RIP command: default-information originate

RIP command: route a.b.c.d/m
RIP command: no route a.b.c.d/m: This command is specific to Quagga. The route command makes a staticroute only inside RIP. This command should be used only by advancedusers who are particularly knowledgeable about the RIP protocol. Inmost cases, we recommend creating a static route in Quagga andredistributing it in RIP using redistribute static.

5.5 Filtering RIP Routes

RIP routes can be filtered by a distribute-list.

Command: distribute-list access_list direct ifname

You can apply access lists to the interface with a distribute-listcommand. access_list is the access list name. direct is‘in’ or ‘out’. If direct is ‘in’ the access listis applied to input packets.

The distribute-list command can be used to filter the RIP path.distribute-list can apply access-lists to a chosen interface.First, one should specify the access-list. Next, the name of theaccess-list is used in the distribute-list command. For example, in thefollowing configuration ‘eth0’ will permit only the paths thatmatch the route 10.0.0.0/8

!
router rip
 distribute-list private in eth0
!
access-list private permit 10 10.0.0.0/8
access-list private deny any
!

distribute-list can be applied to both incoming and outgoing data.

Command: distribute-list prefix prefix_list (in|out) ifname: You can apply prefix lists to the interface with adistribute-list command. prefix_list is the prefix listname. Next is the direction of ‘in’ or ‘out’. Ifdirect is ‘in’ the access list is applied to input packets.

5.6 RIP Metric Manipulation

RIP metric is a value for distance for the network. Usuallyripd increment the metric when the network information isreceived. Redistributed routes’ metric is set to 1.

RIP command: default-metric <1-16>
RIP command: no default-metric <1-16>: This command modifies the default metric value for redistributed routes. Thedefault value is 1. This command does not affect connected routeeven if it is redistributed by redistribute connected. To modifyconnected route’s metric value, please use redistributeconnected metric or route-map. offset-list alsoaffects connected routes.

RIP command: offset-list access-list (in|out)
RIP command: offset-list access-list (in|out) ifname

5.7 RIP distance

Distance value is used in zebra daemon. Default RIP distance is 120.

RIP command: distance <1-255>
RIP command: no distance <1-255>: Set default RIP distance to specified value.

RIP command: distance <1-255> A.B.C.D/M
RIP command: no distance <1-255> A.B.C.D/M: Set default RIP distance to specified value when the route’s source IPaddress matches the specified prefix.

RIP command: distance <1-255> A.B.C.D/M access-list
RIP command: no distance <1-255> A.B.C.D/M access-list: Set default RIP distance to specified value when the route’s source IPaddress matches the specified prefix and the specified access-list.

5.8 RIP route-map

Usage of ripd’s route-map support.

Optional argument route-map MAP_NAME can be added to each redistributestatement.

redistribute static [route-map MAP_NAME]
redistribute connected [route-map MAP_NAME]
.....

Cisco applies route-map _before_ routes will exported to rip route table. In current Quagga’s test implementation, ripd applies route-mapafter routes are listed in the route table and before routes will beannounced to an interface (something like output filter). I think it is notso clear, but it is draft and it may be changed at future.

Route-map statement (see Route Map) is needed to use route-mapfunctionality.

Route Map: match interface word: This command match to incoming interface. Notation of this match isdifferent from Cisco. Cisco uses a list of interfaces - NAME1 NAME2... NAMEN. Ripd allows only one name (maybe will change in thefuture). Next - Cisco means interface which includes next-hop ofroutes (it is somewhat similar to "ip next-hop" statement). Ripdmeans interface where this route will be sent. This difference isbecause "next-hop" of same routes which sends to different interfacesmust be different. Maybe it’d be better to made new matches - say"match interface-out NAME" or something like that.

Route Map: match ip address word
Route Map: match ip address prefix-list word: Match if route destination is permitted by access-list.

Route Map: match ip next-hop word
Route Map: match ip next-hop prefix-list word: Match if route next-hop (meaning next-hop listed in the rip route-tableas displayed by "show ip rip") is permitted by access-list.

Route Map: match metric <0-4294967295>: This command match to the metric value of RIP updates. For otherprotocol compatibility metric range is shown as <0-4294967295>. Butfor RIP protocol only the value range <0-16> make sense.

Route Map: set ip next-hop A.B.C.D: This command set next hop value in RIPv2 protocol. This command doesnot affect RIPv1 because there is no next hop field in the packet.

Route Map: set metric <0-4294967295>: Set a metric for matched route when sending announcement. The metricvalue range is very large for compatibility with other protocols. ForRIP, valid metric values are from 1 to 16.

5.9 RIP Authentication

RIPv2 allows packets to be authenticated via either an insecure plaintext password, included with the packet, or via a more secure MD5 basedHMAC (keyed-Hashing for Message AuthentiCation),RIPv1 can not be authenticated at all, thus when authentication isconfigured ripd will discard routing updates received via RIPv1packets.

However, unless RIPv1 reception is disabled entirely, See RIP Version Control, RIPv1 REQUEST packets which are received,which query the router for routing information, will still be honouredby ripd, and ripd WILL reply to such packets. This allows ripd to honour such REQUESTs (which sometimes is used by oldequipment and very simple devices to bootstrap their default route),while still providing security for route updates which are received.

In short: Enabling authentication prevents routes being updated byunauthenticated remote routers, but still can allow routes (I.e. theentire RIP routing table) to be queried remotely, potentially by anyoneon the internet, via RIPv1.

To prevent such unauthenticated querying of routes disable RIPv1,See RIP Version Control.

Interface command: ip rip authentication mode md5
Interface command: no ip rip authentication mode md5: Set the interface with RIPv2 MD5 authentication.

Interface command: ip rip authentication mode text
Interface command: no ip rip authentication mode text: Set the interface with RIPv2 simple password authentication.

Interface command: ip rip authentication string string
Interface command: no ip rip authentication string string: RIP version 2 has simple text authentication. This command setsauthentication string. The string must be shorter than 16 characters.

Interface command: ip rip authentication key-chain key-chain
Interface command: no ip rip authentication key-chain key-chain: Specifiy Keyed MD5 chain.

!
key chain test
 key 1
  key-string test
!
interface eth1
 ip rip authentication mode md5
 ip rip authentication key-chain test
!

5.10 RIP Timers

RIP command: timers basic update timeout garbage

RIP protocol has several timers. User can configure those timers’ valuesby timers basic command.

The default settings for the timers are as follows:

The update timer is 30 seconds. Every update timer seconds, the RIPprocess is awakened to send an unsolicited Response message containingthe complete routing table to all neighboring RIP routers.
The timeout timer is 180 seconds. Upon expiration of the timeout, theroute is no longer valid; however, it is retained in the routing tablefor a short time so that neighbors can be notified that the route hasbeen dropped.
The garbage collect timer is 120 seconds. Upon expiration of thegarbage-collection timer, the route is finally removed from the routingtable.

The timers basic command allows the the default values of the timerslisted above to be changed.

RIP command: no timers basic: The no timers basic command will reset the timers to the defaultsettings listed above.

5.11 Show RIP Information

To display RIP routes.

Command: show ip rip: Show RIP routes.

The command displays all RIP routes. For routes that are receivedthrough RIP, this command will display the time the packet was sent andthe tag information. This command will also display this informationfor routes redistributed into RIP.

Command: show ip rip status: The command displays current RIP status. It includes RIP timer,filtering, version, RIP enabled interface and RIP peer inforation.

ripd> show ip rip status
Routing Protocol is "rip"
  Sending updates every 30 seconds with +/-50%, next due in 35 seconds
  Timeout after 180 seconds, garbage collect after 120 seconds
  Outgoing update filter list for all interface is not set
  Incoming update filter list for all interface is not set
  Default redistribution metric is 1
  Redistributing: kernel connected
  Default version control: send version 2, receive version 2 
    Interface        Send  Recv
  Routing for Networks:
    eth0
    eth1
    1.1.1.1
    203.181.89.241
  Routing Information Sources:
    Gateway          BadPackets BadRoutes  Distance Last Update

5.12 RIP Debug Commands

Debug for RIP protocol.

Command: debug rip events: Debug rip events.

debug rip will show RIP events. Sending and receivingpackets, timers, and changes in interfaces are events shown with ripd.

Command: debug rip packet: Debug rip packet.

debug rip packet will display detailed information about the RIPpackets. The origin and port number of the packet as well as a packetdump is shown.

Command: debug rip zebra: Debug rip between zebra communication.

This command will show the communication between ripd andzebra. The main information will include addition and deletion ofpaths to the kernel and the sending and receiving of interface information.

Command: show debugging rip: Display ripd’s debugging option.

show debugging rip will show all information currently set for ripddebug.

6 RIPng

ripngd supports the RIPng protocol as described in RFC2080. It’s anIPv6 reincarnation of the RIP protocol.

6.1 Invoking ripngd

There are no ripngd specific invocation options. Common optionscan be specified (see Common Invocation Options).

6.2 ripngd Configuration

Currently ripngd supports the following commands:

Command: router ripng: Enable RIPng.

RIPng Command: flush_timer time: Set flush timer.

RIPng Command: network network: Set RIPng enabled interface by network

RIPng Command: network ifname: Set RIPng enabled interface by ifname

RIPng Command: route network: Set RIPng static routing announcement of network.

Command: router zebra: This command is the default and does not appear in the configuration.With this statement, RIPng routes go to the zebra daemon.

6.3 ripngd Terminal Mode Commands

Command: show ip ripng

Command: show debugging ripng

Command: debug ripng events

Command: debug ripng packet

Command: debug ripng zebra

6.4 ripngd Filtering Commands

Command: distribute-list access_list (in|out) ifname

You can apply an access-list to the interface using thedistribute-list command. access_list is an access-listname. direct is ‘in’ or ‘out’. If direct is‘in’, the access-list is applied only to incoming packets.

distribute-list local-only out sit1

7 OSPFv2

OSPF (Open Shortest Path First) version 2 is a routing protocolwhich is described in RFC2328, OSPF Version 2. OSPF is anIGP (Interior Gateway Protocol). Compared with RIP,OSPF can provide scalable network support and fasterconvergence times. OSPF is widely used in large networks such asISP (Internet Service Provider) backbone and enterprisenetworks.

7.1 OSPF Fundamentals

OSPF is, mostly, a link-state routing protocol. In contrastto distance-vector protocols, such as RIP orBGP, where routers describe available paths (i.e. routes) to each other, in link-state protocols routers insteaddescribe the state of their links to their immediate neighbouringrouters.

Each router describes their link-state information in a message knownas an LSA (Link State Advertisement), which is then propogatedthrough to all other routers in a link-state routing domain, by aprocess called flooding. Each router thus builds up anLSDB (Link State Database) of all the link-state messages. Fromthis collection of LSAs in the LSDB, each router can then calculate theshortest path to any other router, based on some common metric, byusing an algorithm such as Edgser Dijkstra’s SPF (Shortest Path First).

By describing connectivity of a network in this way, in terms ofrouters and links rather than in terms of the paths through a network,a link-state protocol can use less bandwidth and converge more quicklythan other protocols. A link-state protocol need distribute only onelink-state message throughout the link-state domain when a link on anysingle given router changes state, in order for all routers toreconverge on the best paths through the network. In contrast, distancevector protocols can require a progression of different path updatemessages from a series of different routers in order to converge.

The disadvantage to a link-state protocol is that the process ofcomputing the best paths can be relatively intensive when compared todistance-vector protocols, in which near to no computation need be doneother than (potentially) select between multiple routes. This overheadis mostly negligible for modern embedded CPUs, even for networks withthousands of nodes. The primary scaling overhead lies more in copingwith the ever greater frequency of LSA updates as the size of alink-state area increases, in managing the LSDB and requiredflooding.

This section aims to give a distilled, but accurate, description of themore important workings of OSPF which an administrator may needto know to be able best configure and trouble-shoot OSPF.

7.1.1 OSPF Mechanisms

OSPF defines a range of mechanisms, concerned with detecting,describing and propogating state through a network. These mechanismswill nearly all be covered in greater detail further on. They may bebroadly classed as:

The Hello Protocol

The OSPF Hello protocol allows OSPF to quickly detect changes intwo-way reachability between routers on a link. OSPF can additionallyavail of other sources of reachability information, such as link-stateinformation provided by hardware, or through dedicated reachabilityprotocols such as BFD (Bi-directional Forwarding Detection).

OSPF also uses the Hello protocol to propagate certain state betweenrouters sharing a link, for example:

Hello protocol configured state, such as the dead-interval.
Router priority, for DR/BDR election.
DR/BDR election results.
Any optional capabilities supported by each router.

The Hello protocol is comparatively trivial and will not be explored ingreater detail than here.

LSAs

At the heart of OSPF are LSA (Link StateAdvertisement) messages. Despite the name, some LSAs do not,strictly speaking, describe link-state information. CommonLSAs describe information such as:

Routers, in terms of their links.
Networks, in terms of attached routers.
Routes, external to a link-state domain:
- External Routes
  Routes entirely external to OSPF. Routers originating suchroutes are known as ASBR (Autonomous-System Border Router)routers.
- Summary Routes
  Routes which summarise routing information relating to OSPF areasexternal to the OSPF link-state area at hand, originated byABR (Area Boundary Router) routers.

LSA Flooding

OSPF defines several related mechanisms, used to manage synchronisation ofLSDBs between neighbours as neighbours form adjacencies andthe propogation, or flooding of new or updated LSAs.

See OSPF Flooding.

Areas

OSPF provides for the protocol to be broken up into multiple smallerand independent link-state areas. Each area must be connected to acommon backbone area by an ABR (Area Boundary Router). TheseABR routers are responsible for summarising the link-staterouting information of an area into Summary LSAs, possibly in acondensed (i.e. aggregated) form, and then originating these summariesinto all other areas the ABR is connected to.

Note that only summaries and external routes are passed between areas.As these describe paths, rather than any router link-states,routing between areas hence is by distance-vector, notlink-state.

See OSPF Areas.

7.1.2 OSPF LSAs

LSAs are the core object in OSPF. Everything else in OSPFrevolves around detecting what to describe in LSAs, when to updatethem, how to flood them throughout a network and how to calculateroutes from them.

There are a variety of different LSAs, for purposes suchas describing actual link-state information, describing paths (i.e.routes), describing bandwidth usage of links for TE (Traffic Engineering) purposes, and even arbitrary databy way of Opaque LSAs.

7.1.2.1 LSA Header

All LSAs share a common header with the following information:

Type
Different types of LSAs describe different things inOSPF. Types include:
- Router LSA
- Network LSA
- Network Summary LSA
- Router Summary LSA
- AS-External LSA
The specifics of the different types of LSA are examined below.
Advertising Router
The Router ID of the router originating the LSA, see ospf router-id.
LSA ID
The ID of the LSA, which is typically derived in some way from theinformation the LSA describes, e.g. a Router LSA uses the Router ID asthe LSA ID, a Network LSA will have the IP address of the DRas its LSA ID.

The combination of the Type, ID and Advertising Router ID must uniquelyidentify the LSA. There can however be multiple instances ofan LSA with the same Type, LSA ID and Advertising Router ID, seeLSA Sequence Number.
Age
A number to allow stale LSAs to, eventually, be purged by routersfrom their LSDBs.

The value nominally is one of seconds. An age of 3600, i.e. 1 hour, iscalled the MaxAge. MaxAge LSAs are ignored in routingcalculations. LSAs must be periodically refreshed by their AdvertisingRouter before reaching MaxAge if they are to remain valid.

Routers may deliberately flood LSAs with the age artificially set to3600 to indicate an LSA is no longer valid. This is calledflushing of an LSA.

It is not abnormal to see stale LSAs in the LSDB, this can occur wherea router has shutdown without flushing its LSA(s), e.g. where it hasbecome disconnected from the network. Such LSAs do little harm.
Sequence Number
A number used to distinguish newer instances of an LSA from older instances.

7.1.2.2 Link-State LSAs

Of all the various kinds of LSAs, just two types comprise theactual link-state part of OSPF, Router LSAs andNetwork LSAs. These LSA types are absolutely core to theprotocol.

Instances of these LSAs are specific to the link-state area in whichthey are originated. Routes calculated from these two LSA types arecalled intra-area routes.

Router LSA

Each OSPF Router must originate a router LSA to describeitself. In it, the router lists each of its OSPF enabledinterfaces, for the given link-state area, in terms of:

Cost
The output cost of that interface, scaled inversely to some commonly knownreference value, See auto-costreference-bandwidth.
Link Type
- Transit Network
  A link to a multi-access network, on which the router has at least oneFull adjacency with another router.
- PtP (Point-to-Point)
  A link to a single remote router, with a Full adjacency. NoDR (Designated Router) is elected on such links; no networkLSA is originated for such a link.
- Stub
  A link with no adjacent neighbours, or a host route.

Link ID and Data

These values depend on the Link Type:

Link Type	Link ID	Link Data
Transit	Link IP address of the DR	Interface IP address
Point-to-Point	Router ID of the remote router	Local interface IP address,or the ifindex (MIB-II interface index) for unnumbered links
Stub	IP address	Subnet Mask

Links on a router may be listed multiple times in the Router LSA, e.g.a PtP interface on which OSPF is enabled must alwaysbe described by a Stub link in the Router LSA, in addition tobeing listed as PtP link in the Router LSA if the adjacencywith the remote router is Full.

Stub links may also be used as a way to describe links on which OSPF isnot spoken, known as passive interfaces, see passive-interface.

Network LSA
On multi-access links (e.g. ethernets, certain kinds of ATM and X.25configurations), routers elect a DR. The DR isresponsible for originating a Network LSA, which helps reducethe information needed to describe multi-access networks with multiplerouters attached. The DR also acts as a hub for the flooding ofLSAs on that link, thus reducing flooding overheads.

The contents of the Network LSA describes the:
- Subnet Mask
  As the LSA ID of a Network LSA must be the IP address of theDR, the Subnet Mask together with the LSA ID givesyou the network address.
- Attached Routers
  Each router fully-adjacent with the DR is listed in the LSA,by their Router-ID. This allows the corresponding Router LSAs to beeasily retrieved from the LSDB.

Summary of Link State LSAs:

LSA Type	LSA ID Describes	LSA Data Describes
Router LSA	The Router ID	The OSPF enabled links of the router, within a specific link-state area.
Network LSA	The IP address of the DR for the network	The Subnet Mask of the network, and the Router IDs of all routers on the network.

With an LSDB composed of just these two types of LSA, it ispossible to construct a directed graph of the connectivity between allrouters and networks in a given OSPF link-state area. So, notsurprisingly, when OSPF routers build updated routing tables, the firststage of SPF calculation concerns itself only with these twoLSA types.

7.1.2.3 Link-State LSA Examples

The example below (see OSPF Link-State LSA Example) shows twoLSAs, both originated by the same router (Router ID192.168.0.49) and with the same LSA ID (192.168.0.49), but ofdifferent LSA types.

The first LSA being the router LSA describing 192.168.0.49’s links: 2 linksto multi-access networks with fully-adjacent neighbours (i.e. Transitlinks) and 1 being a Stub link (no adjacent neighbours).

The second LSA being a Network LSA, for which 192.168.0.49 is theDR, listing the Router IDs of 4 routers on that network whichare fully adjacent with 192.168.0.49.

# show ip ospf database router 192.168.0.49

       OSPF Router with ID (192.168.0.53)


                Router Link States (Area 0.0.0.0)

  LS age: 38
  Options: 0x2  : *|-|-|-|-|-|E|*
  LS Flags: 0x6  
  Flags: 0x2 : ASBR
  LS Type: router-LSA
  Link State ID: 192.168.0.49 
  Advertising Router: 192.168.0.49
  LS Seq Number: 80000f90
  Checksum: 0x518b
  Length: 60
   Number of Links: 3

    Link connected to: a Transit Network
     (Link ID) Designated Router address: 192.168.1.3
     (Link Data) Router Interface address: 192.168.1.3
      Number of TOS metrics: 0
       TOS 0 Metric: 10

    Link connected to: a Transit Network
     (Link ID) Designated Router address: 192.168.0.49
     (Link Data) Router Interface address: 192.168.0.49
      Number of TOS metrics: 0
       TOS 0 Metric: 10

    Link connected to: Stub Network
     (Link ID) Net: 192.168.3.190
     (Link Data) Network Mask: 255.255.255.255
      Number of TOS metrics: 0
       TOS 0 Metric: 39063
# show ip ospf database network 192.168.0.49

       OSPF Router with ID (192.168.0.53)


                Net Link States (Area 0.0.0.0)

  LS age: 285
  Options: 0x2  : *|-|-|-|-|-|E|*
  LS Flags: 0x6  
  LS Type: network-LSA
  Link State ID: 192.168.0.49 (address of Designated Router)
  Advertising Router: 192.168.0.49
  LS Seq Number: 80000074
  Checksum: 0x0103
  Length: 40
  Network Mask: /29
        Attached Router: 192.168.0.49
        Attached Router: 192.168.0.52
        Attached Router: 192.168.0.53
        Attached Router: 192.168.0.54

Note that from one LSA, you can find the other. E.g. Given theNetwork-LSA you have a list of Router IDs on that network, from whichyou can then look up, in the local LSDB, the matching RouterLSA. From that Router-LSA you may (potentially) find links to otherTransit networks and Routers IDs which can be used to lookup thecorresponding Router or Network LSA. And in that fashion, one can findall the Routers and Networks reachable from that starting LSA.

Given the Router LSA instead, you have the IP address of theDR of any attached transit links. Network LSAs will have that IPas their LSA ID, so you can then look up that Network LSA and from thatfind all the attached routers on that link, leading potentially to morelinks and Network and Router LSAs, etc. etc.

From just the above two LSAs, one can already see thefollowing partial topology:

      
   --------------------- Network: ......
            |            Designated Router IP: 192.168.1.3
            |
      IP: 192.168.1.3
       (transit link)
        (cost: 10)
   Router ID: 192.168.0.49(stub)---------- IP: 192.168.3.190/32
        (cost: 10)        (cost: 39063)
       (transit link)
      IP: 192.168.0.49
            |
            |
------------------------------ Network: 192.168.0.48/29
  |        |           |       Designated Router IP: 192.168.0.49
  |        |           |
  |        |     Router ID: 192.168.0.54
  |        |
  |   Router ID: 192.168.0.53
  |
Router ID: 192.168.0.52

Note the Router IDs, though they look like IP addresses and often areIP addresses, are not strictly speaking IP addresses, nor need they bereachable addresses (though, OSPF will calculate routes to Router IDs).

7.1.2.4 External LSAs

External, or "Type 5", LSAs describe routing information which isentirely external to OSPF, and is "injected" intoOSPF. Such routing information may have come from anotherrouting protocol, such as RIP or BGP, they may represent static routesor they may represent a default route.

An OSPF router which originates External LSAs is known as anASBR (AS Boundary Router). Unlike the link-state LSAs, andmost other LSAs, which are flooded only within the area inwhich they originate, External LSAs are flooded through-outthe OSPF network to all areas capable of carrying ExternalLSAs (see OSPF Areas).

Routes internal to OSPF (intra-area or inter-area) are always preferredover external routes.

The External LSA describes the following:

IP Network number
The IP Network number of the route is described by the LSA IDfield.
IP Network Mask
The body of the External LSA describes the IP Network Mask of theroute. This, together with the LSA ID, describes the prefixof the IP route concerned.
Metric
The cost of the External Route. This cost may be an OSPF cost (alsoknown as a "Type 1" metric), i.e. equivalent to the normal OSPF costs,or an externally derived cost ("Type 2" metric) which is not comparableto OSPF costs and always considered larger than any OSPF cost. Wherethere are both Type 1 and 2 External routes for a route, the Type 1 isalways preferred.
Forwarding Address
The address of the router to forward packets to for the route. This maybe, and usually is, left as 0 to specify that the ASBR originating theExternal LSA should be used. There must be an internal OSPFroute to the forwarding address, for the forwarding address to beuseable.
Tag
An arbitrary 4-bytes of data, not interpreted by OSPF, which maycarry whatever information about the route which OSPF speakers desire.

7.1.2.5 AS External LSA Example

To illustrate, below is an example of an External LSA in theLSDB of an OSPF router. It describes a route to the IP prefixof 192.168.165.0/24, originated by the ASBR with Router-ID192.168.0.49. The metric of 20 is external to OSPF. The forwardingaddress is 0, so the route should forward to the originating ASBR ifselected.

# show ip ospf database external 192.168.165.0
  LS age: 995
  Options: 0x2  : *|-|-|-|-|-|E|*
  LS Flags: 0x9
  LS Type: AS-external-LSA
  Link State ID: 192.168.165.0 (External Network Number)
  Advertising Router: 192.168.0.49
  LS Seq Number: 800001d8
  Checksum: 0xea27
  Length: 36
  Network Mask: /24
        Metric Type: 2 (Larger than any link state path)
        TOS: 0
        Metric: 20
        Forward Address: 0.0.0.0
        External Route Tag: 0

We can add this to our partial topology from above, which now lookslike:

   --------------------- Network: ......
            |            Designated Router IP: 192.168.1.3
            |
      IP: 192.168.1.3      /---- External route: 192.168.165.0/24
       (transit link)     /                Cost: 20 (External metric)
        (cost: 10)       /
   Router ID: 192.168.0.49(stub)---------- IP: 192.168.3.190/32
        (cost: 10)        (cost: 39063)
       (transit link)
      IP: 192.168.0.49
            |
            |
------------------------------ Network: 192.168.0.48/29
  |        |           |       Designated Router IP: 192.168.0.49
  |        |           |
  |        |     Router ID: 192.168.0.54
  |        |
  |   Router ID: 192.168.0.53
  |
Router ID: 192.168.0.52

7.1.2.6 Summary LSAs

Summary LSAs are created by ABRs to summarise the destinations available within one area to other areas. These LSAs may describe IP networks, potentially in aggregated form, or ASBR routers.

7.1.3 OSPF Flooding

7.1.4 OSPF Areas

7.2 Configuring ospfd

There are no ospfd specific options. Common options can bespecified (see Common Invocation Options) to ospfd.ospfd needs to acquire interface information fromzebra in order to function. Therefore zebra must berunning before invoking ospfd. Also, if zebra isrestarted then ospfd must be too.

Like other daemons, ospfd configuration is done in OSPFspecific configuration file ospfd.conf.

7.3 OSPF router

To start OSPF process you have to specify the OSPF router. As of thiswriting, ospfd does not support multiple OSPF processes.

Command: router ospf
Command: no router ospf: Enable or disable the OSPF process. ospfd does not yetsupport multiple OSPF processes. So you can not specify an OSPF processnumber.

OSPF Command: ospf router-id a.b.c.d
OSPF Command: no ospf router-id: This sets the router-ID of the OSPF process. Therouter-ID may be an IP address of the router, but need not be - it canbe any arbitrary 32bit number. However it MUST be unique within theentire OSPF domain to the OSPF speaker - bad things will happen ifmultiple OSPF speakers are configured with the same router-ID! If oneis not specified then ospfd will obtain a router-IDautomatically from zebra.

OSPF Command: ospf abr-type type

OSPF Command: no ospf abr-type type

type can be cisco|ibm|shortcut|standard. The "Cisco" and "IBM" typesare equivalent.

The OSPF standard for ABR behaviour does not allow an ABR to considerroutes through non-backbone areas when its links to the backbone aredown, even when there are other ABRs in attached non-backbone areaswhich still can reach the backbone - this restriction exists primarilyto ensure routing-loops are avoided.

With the "Cisco" or "IBM" ABR type, the default in this release ofQuagga, this restriction is lifted, allowing an ABR to considersummaries learnt from other ABRs through non-backbone areas, and henceroute via non-backbone areas as a last resort when, and only when,backbone links are down.

Note that areas with fully-adjacent virtual-links are considered to be"transit capable" and can always be used to route backbone traffic, andhence are unaffected by this setting (see OSPF virtual-link).

More information regarding the behaviour controlled by this command canbe found in RFC 3509, Alternative Implementations of OSPF AreaBorder Routers, and draft-ietf-ospf-shortcut-abr-02.txt.

Quote: "Though the definition of the ABR (Area Border Router)in the OSPF specification does not require a router with multipleattached areas to have a backbone connection, it is actuallynecessary to provide successful routing to the inter-area andexternal destinations. If this requirement is not met, all trafficdestined for the areas not connected to such an ABR or out of theOSPF domain, is dropped. This document describes alternative ABRbehaviors implemented in Cisco and IBM routers."

OSPF Command: ospf rfc1583compatibility

OSPF Command: no ospf rfc1583compatibility

RFC2328, the sucessor to RFC1583, suggests accordingto section G.2 (changes) in section 16.4 a change to the pathpreference algorithm that prevents possible routing loops that werepossible in the old version of OSPFv2. More specifically it demandsthat inter-area paths and intra-area backbone path are now of equal preferencebut still both preferred to external paths.

This command should NOT be set normally.

OSPF Command: log-adjacency-changes [detail]
OSPF Command: no log-adjacency-changes [detail]: Configures ospfd to log changes in adjacency. With the optionaldetail argument, all changes in adjacency status are shown. Without detail,only changes to full or regressions are shown.

OSPF Command: passive-interface interface
OSPF Command: no passive-interface interface: Do not speak OSPF interface on thegiven interface, but do advertise the interface as a stub link in therouter-LSA (Link State Advertisement) for this router. Thisallows one to advertise addresses on such connected interfaces withouthaving to originate AS-External/Type-5 LSAs (which have global floodingscope) - as would occur if connected addresses were redistributed intoOSPF (see Redistribute routes to OSPF). This is the only way toadvertise non-OSPF links into stub areas.

OSPF Command: timers throttle spf delay initial-holdtime max-holdtime

OSPF Command: no timers throttle spf

This command sets the initial delay, the initial-holdtimeand the maximum-holdtime between when SPF is calculated and theevent which triggered the calculation. The times are specified inmilliseconds and must be in the range of 0 to 600000 milliseconds.

The delay specifies the minimum amount of time to delay SPFcalculation (hence it affects how long SPF calculation is delayed afteran event which occurs outside of the holdtime of any previous SPFcalculation, and also serves as a minimum holdtime).

Consecutive SPF calculations will always be seperated by at least’hold-time’ milliseconds. The hold-time is adaptive and initially isset to the initial-holdtime configured with the above command.Events which occur within the holdtime of the previous SPF calculationwill cause the holdtime to be increased by initial-holdtime, boundedby the maximum-holdtime configured with this command. If the adaptivehold-time elapses without any SPF-triggering event occuring then the current holdtime is reset to the initial-holdtime. The currentholdtime can be viewed with show ip ospf, where it is expressed as a multiplier of the initial-holdtime.

router ospf
 timers throttle spf 200 400 10000

In this example, the delay is set to 200ms, the initialholdtime is set to 400ms and the maximum holdtime to 10s. Hencethere will always be at least 200ms between an event which requires SPFcalculation and the actual SPF calculation. Further consecutive SPFcalculations will always be seperated by between 400ms to 10s, thehold-time increasing by 400ms each time an SPF-triggering event occurswithin the hold-time of the previous SPF calculation.

This command supercedes the timers spf command in previous Quaggareleases.

OSPF Command: max-metric router-lsa [on-startup|on-shutdown] <5-86400>

OSPF Command: max-metric router-lsa administrative

OSPF Command: no max-metric router-lsa [on-startup|on-shutdown|administrative]

This enables RFC3137, OSPF Stub Router Advertisement support,where the OSPF process describes its transit links in its router-LSA ashaving infinite distance so that other routers will avoid calculatingtransit paths through the router while still being able to reachnetworks through the router.

This support may be enabled administratively (and indefinitely) orconditionally. Conditional enabling of max-metric router-lsas can befor a period of seconds after startup and/or for a period of secondsprior to shutdown.

Enabling this for a period after startup allows OSPF to converge fullyfirst without affecting any existing routes used by other routers,while still allowing any connected stub links and/or redistributedroutes to be reachable. Enabling this for a period of time in advanceof shutdown allows the router to gracefully excuse itself from the OSPFdomain.

Enabling this feature administratively allows for administrativeintervention for whatever reason, for an indefinite period of time.Note that if the configuration is written to file, this administrativeform of the stub-router command will also be written to file. Ifospfd is restarted later, the command will then take effectuntil manually deconfigured.

Configured state of this feature as well as current status, such as thenumber of second remaining till on-startup or on-shutdown ends, can beviewed with the show ip ospf command.

OSPF Command: auto-cost reference-bandwidth <1-4294967>

OSPF Command: no auto-cost reference-bandwidth

This sets the referencebandwidth for cost calculations, where this bandwidth is consideredequivalent to an OSPF cost of 1, specified in Mbits/s. The default is100Mbit/s (i.e. a link of bandwidth 100Mbit/s or higher will have acost of 1. Cost of lower bandwidth links will be scaled with referenceto this cost).

This configuration setting MUST be consistent across all routers within theOSPF domain.

OSPF Command: network a.b.c.d/m area a.b.c.d

OSPF Command: network a.b.c.d/m area <0-4294967295>

OSPF Command: no network a.b.c.d/m area a.b.c.d

OSPF Command: no network a.b.c.d/m area <0-4294967295>

This command specifies the OSPF enabled interface(s). If the interface hasan address from range 192.168.1.0/24 then the command below enables ospfon this interface so router can provide network information to the otherospf routers via this interface.

router ospf
 network 192.168.1.0/24 area 0.0.0.0

Prefix length in interface must be equal or bigger (ie. smaller network) thanprefix length in network statement. For example statement above doesn’t enableospf on interface with address 192.168.1.1/23, but it does on interface withaddress 192.168.1.129/25.

Note that the behavior when there is a peer addressdefined on an interface changed after release 0.99.7.Currently, if a peer prefix has been configured,then we test whether the prefix in the network command containsthe destination prefix. Otherwise, we test whether the network command prefixcontains the local address prefix of the interface.

In some cases it may be more convenient to enable OSPF on a perinterface/subnet basis (see OSPF ip ospf area command).

7.4 OSPF area

OSPF Command: area a.b.c.d range a.b.c.d/m

OSPF Command: area <0-4294967295> range a.b.c.d/m

OSPF Command: no area a.b.c.d range a.b.c.d/m

OSPF Command: no area <0-4294967295> range a.b.c.d/m

Summarize intra area paths from specified area into one Type-3 summary-LSAannounced to other areas. This command can be used only in ABR and ONLYrouter-LSAs (Type-1) and network-LSAs (Type-2) (ie. LSAs with scope area) canbe summarized. Type-5 AS-external-LSAs can’t be summarized - their scope is AS.Summarizing Type-7 AS-external-LSAs isn’t supported yet by Quagga.

router ospf
 network 192.168.1.0/24 area 0.0.0.0
 network 10.0.0.0/8 area 0.0.0.10
 area 0.0.0.10 range 10.0.0.0/8

With configuration above one Type-3 Summary-LSA with routing info 10.0.0.0/8 isannounced into backbone area if area 0.0.0.10 contains at least one intra-areanetwork (ie. described with router or network LSA) from this range.

OSPF Command: area a.b.c.d range IPV4_PREFIX not-advertise
OSPF Command: no area a.b.c.d range IPV4_PREFIX not-advertise: Instead of summarizing intra area paths filter them - ie. intra area paths from thisrange are not advertised into other areas.This command makes sense in ABR only.

OSPF Command: area a.b.c.d range IPV4_PREFIX substitute IPV4_PREFIX

OSPF Command: no area a.b.c.d range IPV4_PREFIX substitute IPV4_PREFIX

Substitute summarized prefix with another prefix.

router ospf
 network 192.168.1.0/24 area 0.0.0.0
 network 10.0.0.0/8 area 0.0.0.10
 area 0.0.0.10 range 10.0.0.0/8 substitute 11.0.0.0/8

One Type-3 summary-LSA with routing info 11.0.0.0/8 is announced into backbone area ifarea 0.0.0.10 contains at least one intra-area network (ie. described with router-LSA ornetwork-LSA) from range 10.0.0.0/8.This command makes sense in ABR only.

OSPF Command: area a.b.c.d virtual-link a.b.c.d
OSPF Command: area <0-4294967295> virtual-link a.b.c.d
OSPF Command: no area a.b.c.d virtual-link a.b.c.d
OSPF Command: no area <0-4294967295> virtual-link a.b.c.d

OSPF Command: area a.b.c.d shortcut
OSPF Command: area <0-4294967295> shortcut
OSPF Command: no area a.b.c.d shortcut
OSPF Command: no area <0-4294967295> shortcut: Configure the area as Shortcut capable. See RFC3509. This requiresthat the ’abr-type’ be set to ’shortcut’.

OSPF Command: area a.b.c.d stub
OSPF Command: area <0-4294967295> stub
OSPF Command: no area a.b.c.d stub
OSPF Command: no area <0-4294967295> stub: Configure the area to be a stub area. That is, an area where no routeroriginates routes external to OSPF and hence an area where all external routes are via the ABR(s). Hence, ABRs for such an area do not needto pass AS-External LSAs (type-5s) or ASBR-Summary LSAs (type-4) into thearea. They need only pass Network-Summary (type-3) LSAs into such an area,along with a default-route summary.

OSPF Command: area a.b.c.d stub no-summary
OSPF Command: area <0-4294967295> stub no-summary
OSPF Command: no area a.b.c.d stub no-summary
OSPF Command: no area <0-4294967295> stub no-summary: Prevents an ospfd ABR from injecting inter-area summaries into the specified stub area.

OSPF Command: area a.b.c.d default-cost <0-16777215>
OSPF Command: no area a.b.c.d default-cost <0-16777215>: Set the cost of default-summary LSAs announced to stubby areas.

OSPF Command: area a.b.c.d export-list NAME

OSPF Command: area <0-4294967295> export-list NAME

OSPF Command: no area a.b.c.d export-list NAME

OSPF Command: no area <0-4294967295> export-list NAME

Filter Type-3 summary-LSAs announced to other areas originated from intra-area paths from specified area.

router ospf
 network 192.168.1.0/24 area 0.0.0.0
 network 10.0.0.0/8 area 0.0.0.10
 area 0.0.0.10 export-list foo
!
access-list foo permit 10.10.0.0/16
access-list foo deny any

With example above any intra-area paths from area 0.0.0.10 and from range10.10.0.0/16 (for example 10.10.1.0/24 and 10.10.2.128/30) are announced intoother areas as Type-3 summary-LSA’s, but any others (for example 10.11.0.0/16or 10.128.30.16/30) aren’t.

This command is only relevant if the router is an ABR for the specifiedarea.

OSPF Command: area a.b.c.d import-list NAME
OSPF Command: area <0-4294967295> import-list NAME
OSPF Command: no area a.b.c.d import-list NAME
OSPF Command: no area <0-4294967295> import-list NAME: Same as export-list, but it applies to paths announced into specified area asType-3 summary-LSAs.

OSPF Command: area a.b.c.d filter-list prefix NAME in
OSPF Command: area a.b.c.d filter-list prefix NAME out
OSPF Command: area <0-4294967295> filter-list prefix NAME in
OSPF Command: area <0-4294967295> filter-list prefix NAME out
OSPF Command: no area a.b.c.d filter-list prefix NAME in
OSPF Command: no area a.b.c.d filter-list prefix NAME out
OSPF Command: no area <0-4294967295> filter-list prefix NAME in
OSPF Command: no area <0-4294967295> filter-list prefix NAME out: Filtering Type-3 summary-LSAs to/from area using prefix lists. This commandmakes sense in ABR only.

OSPF Command: area a.b.c.d authentication
OSPF Command: area <0-4294967295> authentication
OSPF Command: no area a.b.c.d authentication
OSPF Command: no area <0-4294967295> authentication: Specify that simple password authentication should be used for the givenarea.

OSPF Command: area a.b.c.d authentication message-digest

OSPF Command: area <0-4294967295> authentication message-digest

Specify that OSPF packetsmust be authenticated with MD5 HMACs within the given area. Keyingmaterial must also be configured on a per-interface basis (see ip ospf message-digest-key).

MD5 authentication may also be configured on a per-interface basis(see ip ospf authentication message-digest). Such per-interfacesettings will override any per-area authentication setting.

7.5 OSPF interface

Interface Command: ip ospf area AREA [ADDR]

Interface Command: no ip ospf area [ADDR]

Enable OSPF on the interface, optionally restricted to just the IP addressgiven by ADDR, putting it in the AREA area. Per interface areasettings take precedence to network commands (see OSPF network command).

If you have a lot of interfaces, and/or a lot of subnets, then enabling OSPFvia this command may result in a slight performance improvement.

Interface Command: ip ospf authentication-key AUTH_KEY

Interface Command: no ip ospf authentication-key

Set OSPF authentication key to a simple password. After setting AUTH_KEY,all OSPF packets are authenticated. AUTH_KEY has length up to 8 chars.

Simple text password authentication is insecure and deprecated in favour ofMD5 HMAC authentication (see ip ospf authentication message-digest).

Interface Command: ip ospf authentication message-digest

Specify that MD5 HMACauthentication must be used on this interface. MD5 keying material mustalso be configured (see ip ospf message-digest-key). Overrides anyauthentication enabled on a per-area basis (see area authentication message-digest).

Note that OSPF MD5 authentication requires that time never go backwards(correct time is NOT important, only that it never goes backwards), evenacross resets, if ospfd is to be able to promptly reestabish adjacencieswith its neighbours after restarts/reboots. The host should have systemtime be set at boot from an external or non-volatile source (eg battery backed clock, NTP,etc.) or else the system clock should be periodically saved to non-volativestorage and restored at boot if MD5 authentication is to be expected to workreliably.

Interface Command: ip ospf message-digest-key KEYID md5 KEY

Interface Command: no ip ospf message-digest-key

Set OSPF authentication key to acryptographic password. The cryptographic algorithm is MD5.

KEYID identifies secret key used to create the message digest. This IDis part of the protocol and must be consistent across routers on alink.

KEY is the actual message digest key, of up to 16 chars (larger stringswill be truncated), and is associated with the given KEYID.

Interface Command: ip ospf cost <1-65535>
Interface Command: no ip ospf cost: Set link cost for the specified interface. The cost value is set to router-LSA’smetric field and used for SPF calculation.

Interface Command: ip ospf dead-interval <1-65535>

Interface Command: ip ospf dead-interval minimal hello-multiplier <2-20>

Interface Command: no ip ospf dead-interval

Set number of seconds forRouterDeadInterval timer value used for Wait Timer and InactivityTimer. This value must be the same for all routers attached to acommon network. The default value is 40 seconds.

If ’minimal’ is specified instead, then the dead-interval is set to 1second and one must specify a hello-multiplier. The hello-multiplierspecifies how many Hellos to send per second, from 2 (every 500ms) to20 (every 50ms). Thus one can have 1s convergence time for OSPF. If this formis specified, then the hello-interval advertised in Hello packets is set to0 and the hello-interval on received Hello packets is not checked, thus the hello-multiplier need NOT be the same across multiple routers on a commonlink.

Interface Command: ip ospf hello-interval <1-65535>

Interface Command: no ip ospf hello-interval

Set number of seconds for HelloInterval timer value. Setting this value,Hello packet will be sent every timer value seconds on the specified interface.This value must be the same for all routers attached to a common network.The default value is 10 seconds.

This command has no effect if ip ospf dead-interval minimal is also specified for the interface.

Interface Command: ip ospf network (broadcast|non-broadcast|point-to-multipoint|point-to-point)
Interface Command: no ip ospf network: Set explicitly network type for specifed interface.

Interface Command: ip ospf priority <0-255>
Interface Command: no ip ospf priority: Set RouterPriority integer value. The router with the highest prioritywill be more eligible to become Designated Router. Setting the valueto 0, makes the router ineligible to become Designated Router. Thedefault value is 1.

Interface Command: ip ospf retransmit-interval <1-65535>
Interface Command: no ip ospf retransmit interval: Set number of seconds for RxmtInterval timer value. This value is usedwhen retransmitting Database Description and Link State Request packets.The default value is 5 seconds.

Interface Command: ip ospf transmit-delay
Interface Command: no ip ospf transmit-delay: Set number of seconds for InfTransDelay value. LSAs’ age should be incremented by this value when transmitting.The default value is 1 seconds.

7.6 Redistribute routes to OSPF

OSPF Command: redistribute (kernel|connected|static|rip|bgp)

OSPF Command: redistribute (kernel|connected|static|rip|bgp) route-map

OSPF Command: redistribute (kernel|connected|static|rip|bgp) metric <0-16777214>

OSPF Command: redistribute (kernel|connected|static|rip|bgp) metric <0-16777214> route-map word

OSPF Command: no redistribute (kernel|connected|static|rip|bgp)

Redistribute routes of the specified protocolor kind into OSPF, with the metric type and metric set if specified,filtering the routes using the given route-map if specified.Redistributed routes may also be filtered with distribute-lists, seeospf distribute-list.

Redistributed routes are distributed as into OSPF as Type-5 ExternalLSAs into links to areas that accept external routes, Type-7 External LSAsfor NSSA areas and are not redistributed at all into Stub areas, whereexternal routes are not permitted.

Note that for connected routes, one may instead usepassive-interface, see OSPF passive-interface.

OSPF Command: default-information originate
OSPF Command: default-information originate metric <0-16777214>
OSPF Command: default-information originate metric <0-16777214> metric-type (1|2)
OSPF Command: default-information originate metric <0-16777214> metric-type (1|2) route-map word
OSPF Command: default-information originate always
OSPF Command: default-information originate always metric <0-16777214>
OSPF Command: default-information originate always metric <0-16777214> metric-type (1|2)
OSPF Command: default-information originate always metric <0-16777214> metric-type (1|2) route-map word
OSPF Command: no default-information originate: Originate an AS-External (type-5) LSA describing a default route intoall external-routing capable areas, of the specified metric and metrictype. If the ’always’ keyword is given then the default is alwaysadvertised, even when there is no default present in the routing table.

OSPF Command: distribute-list NAME out (kernel|connected|static|rip|ospf
OSPF Command: no distribute-list NAME out (kernel|connected|static|rip|ospf: Apply the access-list filter, NAME, toredistributed routes of the given type before allowing the routes toredistributed into OSPF (see OSPF redistribute).

OSPF Command: default-metric <0-16777214>
OSPF Command: no default-metric

OSPF Command: distance <1-255>
OSPF Command: no distance <1-255>

OSPF Command: distance ospf (intra-area|inter-area|external) <1-255>
OSPF Command: no distance ospf

7.7 Showing OSPF information

Command: show ip ospf: Show information on a variety of general OSPF andarea state and configuration information.

Command: show ip ospf interface [INTERFACE]: Show state and configuration of OSPF the specified interface, or allinterfaces if no interface is given.

Command: show ip ospf neighbor
Command: show ip ospf neighbor INTERFACE
Command: show ip ospf neighbor detail
Command: show ip ospf neighbor INTERFACE detail

Command: show ip ospf database
Command: show ip ospf database asbr-summary
Command: show ip ospf database external
Command: show ip ospf database network
Command: show ip ospf database asbr-router
Command: show ip ospf database summary
Command: show ip ospf database … link-state-id
Command: show ip ospf database … link-state-id adv-router adv-router
Command: show ip ospf database … adv-router adv-router
Command: show ip ospf database … link-state-id self-originate
Command: show ip ospf database … self-originate

Command: show ip ospf database max-age

Command: show ip ospf database self-originate

Command: show ip ospf route: Show the OSPF routing table, as determined by the most recent SPF calculation.

7.8 Opaque LSA

OSPF Command: ospf opaque-lsa
OSPF Command: capability opaque
OSPF Command: no ospf opaque-lsa
OSPF Command: no capability opaque: ospfd support Opaque LSA (RFC2370) as fondment for MPLS Traffic Engineering LSA. Prior to used MPLS TE, opaque-lsa must be enable in the configuration file. Alternate command could be "mpls-te on" (OSPF Traffic Engineering).

Command: show ip ospf database (opaque-link|opaque-area|opaque-external)
Command: show ip ospf database (opaque-link|opaque-area|opaque-external) link-state-id
Command: show ip ospf database (opaque-link|opaque-area|opaque-external) link-state-id adv-router adv-router
Command: show ip ospf database (opaque-link|opaque-area|opaque-external) adv-router adv-router
Command: show ip ospf database (opaque-link|opaque-area|opaque-external) link-state-id self-originate
Command: show ip ospf database (opaque-link|opaque-area|opaque-external) self-originate: Show Opaque LSA from the database.

7.9 Traffic Engineering

OSPF Command: mpls-te on
OSPF Command: no mpls-te: Enable Traffic Engineering LSA flooding.

OSPF Command: mpls-te router-address <A.B.C.D>
OSPF Command: no mpls-te: Configure stable IP address for MPLS-TE. This IP address is then advertise in Opaque LSA Type-10 TLV=1 (TE)option 1 (Router-Address).

OSPF Command: mpls-te inter-as area <area-id>|as
OSPF Command: no mpls-te inter-as: Enable RFC5392 suuport - Inter-AS TE v2 - to flood Traffic Engineering parameters of Inter-AS link.2 modes are supported: AREA and AS; LSA are flood in AREA <area-id> with Opaque Type-10, respectively in AS with Opaque Type-11. In all case, Opaque-LSA TLV=6.

Command: show ip ospf mpls-te interface
Command: show ip ospf mpls-te interface interface: Show MPLS Traffic Engineering parameters for all or specified interface.

Command: show ip ospf mpls-te router: Show Traffic Engineering router parameters.

7.10 Router Information

OSPF Command: router-info [as | area <A.B.C.D>]
OSPF Command: no router-info: Enable Router Information (RFC4970) LSA advertisement with AS scope (default) or Area scope floodingwhen area is specified.

OSPF Command: pce address <A.B.C.D>
OSPF Command: no pce address
OSPF Command: pce domain as <0-65535>
OSPF Command: no pce domain as <0-65535>
OSPF Command: pce neighbor as <0-65535>
OSPF Command: no pce neighbor as <0-65535>
OSPF Command: pce flag BITPATTERN
OSPF Command: no pce flag
OSPF Command: pce scope BITPATTERN
OSPF Command: no pce scope: The commands are conform to RFC 5088 and allow OSPF router announce Path Compuatation Elemenent (PCE) capabilitiesthrough the Router Information (RI) LSA. Router Information must be enable prior to this. The command set/unsetrespectively the PCE IP adress, Autonomous System (AS) numbers of controlled domains, neighbor ASs, flag and scope.For flag and scope, please refer to RFC5088 for the BITPATTERN recognition. Multiple ’pce neighbor’ command couldbe specified in order to specify all PCE neighbours.

Command: show ip ospf router-info: Show Router Capabilities flag.

Command: show ip ospf router-info pce: Show Router Capabilities PCE parameters.

7.11 Debugging OSPF

Command: debug ospf packet (hello|dd|ls-request|ls-update|ls-ack|all) (send|recv) [detail]
Command: no debug ospf packet (hello|dd|ls-request|ls-update|ls-ack|all) (send|recv) [detail]: Dump Packet for debugging

Command: debug ospf ism
Command: debug ospf ism (status|events|timers)
Command: no debug ospf ism
Command: no debug ospf ism (status|events|timers): Show debug information of Interface State Machine

Command: debug ospf nsm
Command: debug ospf nsm (status|events|timers)
Command: no debug ospf nsm
Command: no debug ospf nsm (status|events|timers): Show debug information of Network State Machine

Command: debug ospf event
Command: no debug ospf event: Show debug information of OSPF event

Command: debug ospf nssa
Command: no debug ospf nssa: Show debug information about Not So Stub Area

Command: debug ospf lsa
Command: debug ospf lsa (generate|flooding|refresh)
Command: no debug ospf lsa
Command: no debug ospf lsa (generate|flooding|refresh): Show debug detail of Link State messages

Command: debug ospf te
Command: no debug ospf te: Show debug information about Traffic Engineering LSA

Command: debug ospf zebra
Command: debug ospf zebra (interface|redistribute)
Command: no debug ospf zebra
Command: no debug ospf zebra (interface|redistribute): Show debug information of ZEBRA API

Command: show debugging ospf

7.12 OSPF Configuration Examples

A simple example, with MD5 authentication enabled:

!
interface bge0
 ip ospf authentication message-digest
 ip ospf message-digest-key 1 md5 ABCDEFGHIJK
!
router ospf
 network 192.168.0.0/16 area 0.0.0.1
 area 0.0.0.1 authentication message-digest

An ABR router, with MD5 authentication and performing summarisationof networks between the areas:

!
password ABCDEF
log file /var/log/quagga/ospfd.log
service advanced-vty
!
interface eth0
 ip ospf authentication message-digest
 ip ospf message-digest-key 1 md5 ABCDEFGHIJK
!
interface ppp0
!
interface br0
 ip ospf authentication message-digest
 ip ospf message-digest-key 2 md5 XYZ12345
!
router ospf
 ospf router-id 192.168.0.1
 redistribute connected
 passive interface ppp0
 network 192.168.0.0/24 area 0.0.0.0
 network 10.0.0.0/16 area 0.0.0.0
 network 192.168.1.0/24 area 0.0.0.1
 area 0.0.0.0 authentication message-digest
 area 0.0.0.0 range 10.0.0.0/16
 area 0.0.0.0 range 192.168.0.0/24
 area 0.0.0.1 authentication message-digest
 area 0.0.0.1 range 10.2.0.0/16
!

A Traffic Engineering configuration, with Inter-ASv2 support.

- First, the ’zebra.conf’ part:

hostname HOSTNAME
password PASSWORD
log file /var/log/zebra.log
!
interface eth0
 ip address 198.168.1.1/24
 mpls-te on
 mpls-te link metric 10
 mpls-te link max-bw 1.25e+06
 mpls-te link max-rsv-bw 1.25e+06
 mpls-te link unrsv-bw 0 1.25e+06
 mpls-te link unrsv-bw 1 1.25e+06
 mpls-te link unrsv-bw 2 1.25e+06
 mpls-te link unrsv-bw 3 1.25e+06
 mpls-te link unrsv-bw 4 1.25e+06
 mpls-te link unrsv-bw 5 1.25e+06
 mpls-te link unrsv-bw 6 1.25e+06
 mpls-te link unrsv-bw 7 1.25e+06
 mpls-te link rsc-clsclr 0xab
!
interface eth1
 ip address 192.168.2.1/24
 mpls-te on
 mpls-te link metric 10
 mpls-te link max-bw 1.25e+06
 mpls-te link max-rsv-bw 1.25e+06
 mpls-te link unrsv-bw 0 1.25e+06
 mpls-te link unrsv-bw 1 1.25e+06
 mpls-te link unrsv-bw 2 1.25e+06
 mpls-te link unrsv-bw 3 1.25e+06
 mpls-te link unrsv-bw 4 1.25e+06
 mpls-te link unrsv-bw 5 1.25e+06
 mpls-te link unrsv-bw 6 1.25e+06
 mpls-te link unrsv-bw 7 1.25e+06
 mpls-te link rsc-clsclr 0xab
 mpls-te neighbor 192.168.2.2 as 65000

- Then the ’ospfd.conf’ itself:

hostname HOSTNAME
password PASSWORD
log file /var/log/ospfd.log
!
!
interface eth0
 ip ospf hello-interval 60
 ip ospf dead-interval 240
!
interface eth1
 ip ospf hello-interval 60
 ip ospf dead-interval 240
!
!
router ospf
 ospf router-id 192.168.1.1
 network 192.168.0.0/16 area 1
 ospf opaque-lsa
  mpls-te
  mpls-te router-address 192.168.1.1
  mpls-te inter-as area 1
!
line vty

A router information example with PCE advsertisement:

!
router ospf
 ospf router-id 192.168.1.1
 network 192.168.0.0/16 area 1
 capability opaque
  mpls-te
  mpls-te router-address 192.168.1.1
 router-info area 0.0.0.1
  pce address 192.168.1.1
  pce flag 0x80
  pce domain as 65400
  pce neighbor as 65500
  pce neighbor as 65200
  pce scope 0x80
!

8 OSPFv3

ospf6d is a daemon support OSPF version 3 for IPv6 network.OSPF for IPv6 is described in RFC2740.

8.1 OSPF6 router

Command: router ospf6

OSPF6 Command: router-id a.b.c.d: Set router’s Router-ID.

OSPF6 Command: interface ifname area area: Bind interface to specified area, and start sending OSPF packets. area canbe specified as 0.

OSPF6 Command: timers throttle spf delay initial-holdtime max-holdtime

OSPF6 Command: no timers throttle spf

Consecutive SPF calculations will always be seperated by at least’hold-time’ milliseconds. The hold-time is adaptive and initially isset to the initial-holdtime configured with the above command.Events which occur within the holdtime of the previous SPF calculationwill cause the holdtime to be increased by initial-holdtime, boundedby the maximum-holdtime configured with this command. If the adaptivehold-time elapses without any SPF-triggering event occuring thenthe current holdtime is reset to the initial-holdtime.

router ospf6
 timers throttle spf 200 400 10000

OSPF6 Command: auto-cost reference-bandwidth cost

OSPF6 Command: no auto-cost reference-bandwidth

This sets the reference bandwidth for cost calculations, where thisbandwidth is considered equivalent to an OSPF cost of 1, specified inMbits/s. The default is 100Mbit/s (i.e. a link of bandwidth 100Mbit/sor higher will have a cost of 1. Cost of lower bandwidth links will bescaled with reference to this cost).

This configuration setting MUST be consistent across all routerswithin the OSPF domain.

8.2 OSPF6 area

Area support for OSPFv3 is not yet implemented.

8.3 OSPF6 interface

Interface Command: ipv6 ospf6 cost COST: Sets interface’s output cost. Default value depends on the interfacebandwidth and on the auto-cost reference bandwidth.

Interface Command: ipv6 ospf6 hello-interval HELLOINTERVAL: Sets interface’s Hello Interval. Default 40

Interface Command: ipv6 ospf6 dead-interval DEADINTERVAL: Sets interface’s Router Dead Interval. Default value is 40.

Interface Command: ipv6 ospf6 retransmit-interval RETRANSMITINTERVAL: Sets interface’s Rxmt Interval. Default value is 5.

Interface Command: ipv6 ospf6 priority PRIORITY: Sets interface’s Router Priority. Default value is 1.

Interface Command: ipv6 ospf6 transmit-delay TRANSMITDELAY: Sets interface’s Inf-Trans-Delay. Default value is 1.

Interface Command: ipv6 ospf6 network (broadcast|point-to-point): Set explicitly network type for specifed interface.

8.4 Redistribute routes to OSPF6

OSPF6 Command: redistribute static
OSPF6 Command: redistribute connected
OSPF6 Command: redistribute ripng

8.5 Showing OSPF6 information

Command: show ipv6 ospf6 [INSTANCE_ID]: INSTANCE_ID is an optional OSPF instance ID. To see router ID and OSPFinstance ID, simply type "show ipv6 ospf6 <cr>".

Command: show ipv6 ospf6 database: This command shows LSA database summary. You can specify the type of LSA.

Command: show ipv6 ospf6 interface: To see OSPF interface configuration like costs.

Command: show ipv6 ospf6 neighbor: Shows state and chosen (Backup) DR of neighbor.

Command: show ipv6 ospf6 request-list A.B.C.D: Shows requestlist of neighbor.

Command: show ipv6 route ospf6: This command shows internal routing table.

8.6 OSPF6 Configuration Examples

Example of ospf6d configured on one interface and area:

interface eth0
 ipv6 ospf6 instance-id 0
!
router ospf6
 router-id 212.17.55.53
 area 0.0.0.0 range 2001:770:105:2::/64
 interface eth0 area 0.0.0.0
!

9 ISIS

ISIS (Intermediate System to Intermediate System) is a routing protocolwhich is described in ISO10589, RFC1195, RFC5308. ISIS is anIGP (Interior Gateway Protocol). Compared with RIP,ISIS can provide scalable network support and fasterconvergence times like OSPF. ISIS is widely used in large networks such asISP (Internet Service Provider) and carrier backbone networks.

9.1 Configuring isisd

There are no isisd specific options. Common options can bespecified (see Common Invocation Options) to isisd.isisd needs to acquire interface information fromzebra in order to function. Therefore zebra must berunning before invoking isisd. Also, if zebra isrestarted then isisd must be too.

Like other daemons, isisd configuration is done in ISISspecific configuration file isisd.conf.

9.2 ISIS router

To start ISIS process you have to specify the ISIS router. As of thiswriting, isisd does not support multiple ISIS processes.

Command: router isis WORD
Command: no router isis WORD: Enable or disable the ISIS process by specifying the ISIS domain with ’WORD’.isisd does not yet support multiple ISIS processes but you must specifythe name of ISIS process. The ISIS process name ’WORD’ is then used for interface(see command ip router isis WORD).

ISIS Command: net XX.XXXX. ... .XXX.XX
ISIS Command: no net XX.XXXX. ... .XXX.XX: Set/Unset network entity title (NET) provided in ISO format.

ISIS Command: hostname dynamic
ISIS Command: no hostname dynamic: Enable support for dynamic hostname.

ISIS Command: area-password [clear | md5] <password>
ISIS Command: domain-password [clear | md5] <password>
ISIS Command: no area-password
ISIS Command: no domain-password: Configure the authentication password for an area, respectively a domain,as clear text or md5 one.

ISIS Command: log-adjacency-changes
ISIS Command: no log-adjacency-changes: Log changes in adjacency state.

ISIS Command: metric-style [narrow | transition | wide]
ISIS Command: no metric-style: Set old-style (ISO 10589) or new-style packet formats: - narrow Use old style of TLVs with narrow metric - transition Send and accept both styles of TLVs during transition - wide Use new style of TLVs to carry wider metric

ISIS Command: set-overload-bit
ISIS Command: no set-overload-bit: Set overload bit to avoid any transit traffic.

9.3 ISIS Timer

ISIS Command: lsp-gen-interval <1-120>
ISIS Command: lsp-gen-interval [level-1 | level-2] <1-120>
ISIS Command: no lsp-gen-interval
ISIS Command: no lsp-gen-interval [level-1 | level-2]: Set minimum interval in seconds between regenerating same LSP,globally, for an area (level-1) or a domain (level-2).

ISIS Command: lsp-refresh-interval <1-65235>
ISIS Command: lsp-refresh-interval [level-1 | level-2] <1-65235>
ISIS Command: no lsp-refresh-interval
ISIS Command: no lsp-refresh-interval [level-1 | level-2]: Set LSP refresh interval in seconds, globally, for an area (level-1) or a domain (level-2).

ISIS Command: lsp-refresh-interval <1-65235>
ISIS Command: lsp-refresh-interval [level-1 | level-2] <1-65235>
ISIS Command: no lsp-refresh-interval
ISIS Command: no lsp-refresh-interval [level-1 | level-2]: Set LSP refresh interval in seconds, globally, for an area (level-1) or a domain (level-2).

ISIS Command: max-lsp-lifetime <360-65535>
ISIS Command: max-lsp-lifetime [level-1 | level-2] <360-65535>
ISIS Command: no max-lsp-lifetime
ISIS Command: no max-lsp-lifetime [level-1 | level-2]: Set LSP maximum LSP lifetime in seconds, globally, for an area (level-1) or a domain (level-2).

ISIS Command: spf-interval <1-120>
ISIS Command: spf-interval [level-1 | level-2] <1-120>
ISIS Command: no spf-interval
ISIS Command: no spf-interval [level-1 | level-2]: Set minimum interval between consecutive SPF calculations in seconds.

9.4 ISIS region

ISIS Command: is-type [level-1 | level-1-2 | level-2-only]
ISIS Command: no is-type: Define the ISIS router behavior: - level-1 Act as a station router only - level-1-2 Act as both a station router and an area router - level-2-only Act as an area router only

9.5 ISIS interface

Interface Command: ip router isis WORD
Interface Command: no ip router isis WORD: Activate ISIS adjacency on this interface. Note that the nameof ISIS instance must be the same as the one used to configure the ISIS process(see command router isis WORD).

Interface Command: isis circuit-type [level-1 | level-1-2 | level-2]
Interface Command: no isis circuit-type: Configure circuit type for interface: - level-1 Level-1 only adjacencies are formed - level-1-2 Level-1-2 adjacencies are formed - level-2-only Level-2 only adjacencies are formed

Interface Command: isis csnp-interval <1-600>
Interface Command: isis csnp-interval <1-600> [level-1 | level-2]
Interface Command: no isis csnp-interval
Interface Command: no isis csnp-interval [level-1 | level-2]: Set CSNP interval in seconds globally, for an area (level-1) or a domain (level-2).

Interface Command: isis hello padding: Add padding to IS-IS hello packets.

Interface Command: isis hello-interval <1-600>
Interface Command: isis hello-interval <1-600> [level-1 | level-2]
Interface Command: no isis hello-interval
Interface Command: no isis hello-interval [level-1 | level-2]: Set Hello interval in seconds globally, for an area (level-1) or a domain (level-2).

Interface Command: isis hello-multiplier <2-100>
Interface Command: isis hello-multiplier <2-100> [level-1 | level-2]
Interface Command: no isis hello-multiplier
Interface Command: no isis hello-multiplier [level-1 | level-2]: Set multiplier for Hello holding time globally, for an area (level-1) or a domain (level-2).

Interface Command: isis metric [<0-255> | <0-16777215>]
Interface Command: isis metric [<0-255> | <0-16777215>] [level-1 | level-2]
Interface Command: no isis metric
Interface Command: no isis metric [level-1 | level-2]: Set default metric value globally, for an area (level-1) or a domain (level-2).Max value depend if metric support narrow or wide value (see command metric-style).

Interface Command: isis network point-to-point
Interface Command: no isis network point-to-point: Set network type to ’Point-to-Point’ (broadcast by default).

Interface Command: isis passive
Interface Command: no isis passive: Configure the passive mode for this interface.

Interface Command: isis password [clear | md5] <password>
Interface Command: no isis password: Configure the authentication password (clear or encoded text) for the interface.

Interface Command: isis priority <0-127>
Interface Command: isis priority <0-127> [level-1 | level-2]
Interface Command: no isis priority
Interface Command: no isis priority [level-1 | level-2]: Set priority for Designated Router election, globally, for the area (level-1)or the domain (level-2).

Interface Command: isis psnp-interval <1-120>
Interface Command: isis psnp-interval <1-120> [level-1 | level-2]
Interface Command: no isis psnp-interval
Interface Command: no isis psnp-interval [level-1 | level-2]: Set PSNP interval in seconds globally, for an area (level-1) or a domain (level-2).

9.6 Showing ISIS information

Command: show isis summary: Show summary information about ISIS.

Command: show isis hostname: Show information about ISIS node.

Command: show isis interface
Command: show isis interface detail
Command: show isis interface <interface name>: Show state and configuration of ISIS specified interface, or allinterfaces if no interface is given with or without details.

Command: show isis neighbor
Command: show isis neighbor <System Id>
Command: show isis neighbor detail: Show state and information of ISIS specified neighbor, or allneighbors if no system id is given with or without details.

Command: show isis database
Command: show isis database [detail]
Command: show isis database <LSP id> [detail]
Command: show isis database detail <LSP id>: Show the ISIS database globally, for a specific LSP id without or with details.

Command: show isis topology
Command: show isis topology [level-1|level-2]: Show topology IS-IS paths to Intermediate Systems, globally,in area (level-1) or domain (level-2).

Command: show ip route isis: Show the ISIS routing table, as determined by the most recent SPF calculation.

9.7 Traffic Engineering

ISIS Command: mpls-te on
ISIS Command: no mpls-te: Enable Traffic Engineering LSP flooding.

ISIS Command: mpls-te router-address <A.B.C.D>
ISIS Command: no mpls-te router-address: Configure stable IP address for MPLS-TE.

Command: show isis mpls-te interface
Command: show isis mpls-te interface interface: Show MPLS Traffic Engineering parameters for all or specified interface.

Command: show isis mpls-te router: Show Traffic Engineering router parameters.

9.8 Debugging ISIS

Command: debug isis adj-packets
Command: no debug isis adj-packets: IS-IS Adjacency related packets.

Command: debug isis checksum-errors
Command: no debug isis checksum-errors: IS-IS LSP checksum errors.

Command: debug isis events
Command: no debug isis events: IS-IS Events.

Command: debug isis local-updates
Command: no debug isis local-updates: IS-IS local update packets.

Command: debug isis packet-dump
Command: no debug isis packet-dump: IS-IS packet dump.

Command: debug isis protocol-errors
Command: no debug isis protocol-errors: IS-IS LSP protocol errors.

Command: debug isis route-events
Command: no debug isis route-events: IS-IS Route related events.

Command: debug isis snp-packets
Command: no debug isis snp-packets: IS-IS CSNP/PSNP packets.

Command: debug isis spf-events
Command: debug isis spf-statistics
Command: debug isis spf-triggers
Command: no debug isis spf-events
Command: no debug isis spf-statistics
Command: no debug isis spf-triggers: IS-IS Shortest Path First Events, Timing and Statistic Dataand triggering events.

Command: debug isis update-packets
Command: no debug isis update-packets: Update related packets.

Command: show debugging isis: Print which ISIS debug level is activate.

9.9 ISIS Configuration Examples

A simple example, with MD5 authentication enabled:

!
interface eth0
 ip router isis FOO
 isis network point-to-point
 isis circuit-type level-2-only
!
router isis FOO
net 47.0023.0000.0000.0000.0000.0000.0000.1900.0004.00
 metric-style wide
 is-type level-2-only

A Traffic Engineering configuration, with Inter-ASv2 support.

- First, the ’zebra.conf’ part:

hostname HOSTNAME
password PASSWORD
log file /var/log/zebra.log
!
interface eth0
 ip address 10.2.2.2/24
 mpls-te on
 mpls-te link metric 10
 mpls-te link max-bw 1.25e+06
 mpls-te link max-rsv-bw 1.25e+06
 mpls-te link unrsv-bw 0 1.25e+06
 mpls-te link unrsv-bw 1 1.25e+06
 mpls-te link unrsv-bw 2 1.25e+06
 mpls-te link unrsv-bw 3 1.25e+06
 mpls-te link unrsv-bw 4 1.25e+06
 mpls-te link unrsv-bw 5 1.25e+06
 mpls-te link unrsv-bw 6 1.25e+06
 mpls-te link unrsv-bw 7 1.25e+06
 mpls-te link rsc-clsclr 0xab
!
interface eth1
 ip address 10.1.1.1/24
 mpls-te on
 mpls-te link metric 10
 mpls-te link max-bw 1.25e+06
 mpls-te link max-rsv-bw 1.25e+06
 mpls-te link unrsv-bw 0 1.25e+06
 mpls-te link unrsv-bw 1 1.25e+06
 mpls-te link unrsv-bw 2 1.25e+06
 mpls-te link unrsv-bw 3 1.25e+06
 mpls-te link unrsv-bw 4 1.25e+06
 mpls-te link unrsv-bw 5 1.25e+06
 mpls-te link unrsv-bw 6 1.25e+06
 mpls-te link unrsv-bw 7 1.25e+06
 mpls-te link rsc-clsclr 0xab
 mpls-te neighbor 10.1.1.2 as 65000

- Then the ’isisd.conf’ itself:

hostname HOSTNAME
password PASSWORD
log file /var/log/isisd.log
!
!
interface eth0
 ip router isis FOO
!
interface eth1
 ip router isis FOO
!
!
router isis FOO
 isis net 47.0023.0000.0000.0000.0000.0000.0000.1900.0004.00
  mpls-te on
  mpls-te router-address 10.1.1.1
!
line vty

10 NHRP

nhrpd is a daemon to support Next Hop Routing Protocol (NHRP).NHRP is described in RFC2332.

NHRP is used to improve the efficiency of routing computer networktraffic over Non-Broadcast, Multiple Access (NBMA) Networks. NHRP providesan ARP-like solution that allows a system to dynamically learn the NBMAaddress of the other systems that are part of that network, allowingthese systems to directly communicate without requiring traffic to usean intermediate hop.

Cisco Dynamic Multipoint VPN (DMVPN) is based on NHRP, and Quagga nrhpdimplements this scenario.

10.1 Routing Design

nhrpd never handles routing of prefixes itself. You need to run somereal routing protocol (e.g. BGP) to advertise routes over the tunnels.What nhrpd does it establishes ’shortcut routes’ that optimizes therouting protocol to avoid going through extra nodes in NBMA GRE mesh.

nhrpd does route NHRP domain addresses individually using per-host prefixes.This is similar to Cisco FlexVPN; but in contrast to opennhrp which usesa generic subnet route.

To create NBMA GRE tunnel you might use the following (linux terminalcommands):

 ip tunnel add gre1 mode gre key 42 ttl 64
 ip addr add 10.255.255.2/32 dev gre1
 ip link set gre1 up

Note that the IP-address is assigned as host prefix to gre1. nhrpd willautomatically create additional host routes pointing to gre1 whena connection with these hosts is established.

The gre1 subnet prefix should be announced by routing protocol from thehub nodes (e.g. BGP ’network’ announce). This allows the routing protocolto decide which is the closest hub and determine the relay hub on prefixbasis when direct tunnel is not established.

nhrpd will redistribute directly connected neighbors to zebra. Withinhub nodes, these routes should be internally redistributed using somerouting protocol (e.g. iBGP) to allow hubs to be able to relay all traffic.

This can be achieved in hubs with the following bgp configuration (networkcommand defines the GRE subnet):

router bgp 65555
   network 172.16.0.0/16
   redistribute nhrp

10.2 Configuring NHRP

FIXME

10.3 Hub Functionality

In addition to routing nhrp redistributed host prefixes, the hub nodesare also responsible to send NHRP Traffic Indication messages thattrigger creation of the shortcut tunnels.

nhrpd sends Traffic Indication messages based on network traffic capturedusing NFLOG. Typically you want to send Traffic Indications for networktraffic that is routed from gre1 back to gre1 in rate limited manner.This can be achieved with the following iptables rule.

iptables -A FORWARD -i gre1 -o gre1 \
	-m hashlimit --hashlimit-upto 4/minute --hashlimit-burst 1 \
	--hashlimit-mode srcip,dstip --hashlimit-srcmask 24 \
	--hashlimit-dstmask 24 --hashlimit-name loglimit-0 \
	-j NFLOG --nflog-group 1 --nflog-range 128

You can fine tune the src/dstmask according to the prefix lengths youannounce internal, add additional IP range matches, or rate limitationif needed. However, the above should be good in most cases.

This kernel NFLOG target’s nflog-group is configured in global nhrp configwith:

nhrp nflog-group 1

To start sending these traffic notices out from hubs, use the nhrpper-interface directive:

interface gre1
 ip nhrp redirect

10.4 Integration with IKE

nhrpd needs tight integration with IKE daemon for various reasons.Currently only strongSwan is supported as IKE daemon.

nhrpd connects to strongSwan using VICI protocol based on UNIX socket(hardcoded now as /var/run/charon.vici).

strongSwan currently needs few patches applied. Please check out thereleaseandworking treegit repositories for the patches.

10.5 NHRP Events

FIXME

10.6 Configuration Example

FIXME

11 BGP

BGP stands for a Border Gateway Protocol. The lastest BGP versionis 4. It is referred as BGP-4. BGP-4 is one of the Exterior GatewayProtocols and de-fact standard of Inter Domain routing protocol.BGP-4 is described in RFC1771, A Border Gateway Protocol4 (BGP-4).

Many extensions have been added to RFC1771. RFC2858,Multiprotocol Extensions for BGP-4 provides multiprotocol support toBGP-4.

11.1 Starting BGP

Default configuration file of bgpd is bgpd.conf.bgpd searches the current directory first then/etc/quagga/bgpd.conf. All of bgpd’s command must beconfigured in bgpd.conf.

bgpd specific invocation options are described below. Commonoptions may also be specified (see Common Invocation Options).

‘-p PORT’
‘--bgp_port=PORT’: Set the bgp protocol’s port number.
‘-r’
‘--retain’: When program terminates, retain BGP routes added by zebra.
‘-l’
‘--listenon’: Specify a specific IP address for bgpd to listen on, rather than its default of INADDR_ANY / IN6ADDR_ANY. This can be useful to constrain bgpdto an internal address, or to run multiple bgpd processes on one host.

11.2 BGP router

First of all you must configure BGP router with router bgpcommand. To configure BGP router, you need AS number. AS number is anidentification of autonomous system. BGP protocol uses the AS numberfor detecting whether the BGP connection is internal one or external one.

Command: router bgp asn: Enable a BGP protocol process with the specified asn. Afterthis statement you can input any BGP Commands. You can notcreate different BGP process under different asn withoutspecifying multiple-instance (see Multiple instance).

Command: no router bgp asn: Destroy a BGP protocol process with the specified asn.

BGP: bgp router-id A.B.C.D: This command specifies the router-ID. If bgpd connects to zebra it getsinterface and address information. In that case default router ID valueis selected as the largest IP Address of the interfaces. Whenrouter zebra is not enabled bgpd can’t get interface informationso router-id is set to 0.0.0.0. So please set router-id by hand.

11.2.1 BGP distance

BGP: distance bgp <1-255> <1-255> <1-255>: This command change distance value of BGP. Each argument is distancevalue for external routes, internal routes and local routes.

BGP: distance <1-255> A.B.C.D/M
BGP: distance <1-255> A.B.C.D/M word: This command set distance value to

11.2.2 BGP decision process

The decision process Quagga BGP uses to select routes is as follows:

1. Weight check: prefer higher local weight routes to lower routes.
2. Local preference check: prefer higher local preference routes to lower.
3. Local route check: Prefer local routes (statics, aggregates, redistributed) to received routes.
4. AS path length check: Prefer shortest hop-count AS_PATHs.
5. Origin check: Prefer the lowest origin type route. That is, prefer IGP origin routes toEGP, to Incomplete routes.
6. MED check: Where routes with a MED were received from the same AS,prefer the route with the lowest MED. See BGP MED.
7. External check: Prefer the route received from an external, eBGP peerover routes received from other types of peers.
8. IGP cost check: Prefer the route with the lower IGP cost.
9. Multi-path check: If multi-pathing is enabled, then check whetherthe routes not yet distinguished in preference may be considered equal. Ifbgp bestpath as-path multipath-relax is set, all such routes areconsidered equal, otherwise routes received via iBGP with identical AS_PATHsor routes received from eBGP neighbours in the same AS are considered equal.
10 Already-selected external check: Where both routes were received from eBGP peers, then prefer the route whichis already selected. Note that this check is not applied if bgp bestpath compare-routerid is configured. This check can prevent some casesof oscillation.
11. Router-ID check: Prefer the route with the lowest router-ID. If theroute has an ORIGINATOR_ID attribute, through iBGP reflection, then thatrouter ID is used, otherwise the router-ID of the peer the route wasreceived from is used.
12. Cluster-List length check: The route with the shortest cluster-listlength is used. The cluster-list reflects the iBGP reflection path theroute has taken.
13. Peer address: Prefer the route received from the peer with the highertransport layer address, as a last-resort tie-breaker.

BGP: bgp bestpath as-path confed: This command specifies that the length of confederation path sets andsequences should should be taken into account during the BGP best pathdecision process.

BGP: bgp bestpath as-path multipath-relax: This command specifies that BGP decision process should consider pathsof equal AS_PATH length candidates for multipath computation. Withoutthe knob, the entire AS_PATH must match for multipath computation.

BGP: bgp bestpath compare-routerid

Ensure that when comparing routes where both are equal on most metrics,including local-pref, AS_PATH length, IGP cost, MED, that the tie is brokenbased on router-ID.

If this option is enabled, then the already-selected check, wherealready selected eBGP routes are preferred, is skipped.

If a route has an ORIGINATOR_ID attribute because it has been reflected,that ORIGINATOR_ID will be used. Otherwise, the router-ID of the peer theroute was received from will be used.

The advantage of this is that the route-selection (at this point) will bemore deterministic. The disadvantage is that a few or even one lowest-IDrouter may attract all trafic to otherwise-equal paths because of thischeck. It may increase the possibility of MED or IGP oscillation, unlessother measures were taken to avoid these. The exact behaviour will besensitive to the iBGP and reflection topology.

11.2.3 BGP route flap dampening

BGP: bgp dampening <1-45> <1-20000> <1-20000> <1-255>

This command enables BGP route-flap dampening and specifies dampening parameters.

half-life: Half-life time for the penalty
reuse-threshold: Value to start reusing a route
suppress-threshold: Value to start suppressing a route
max-suppress: Maximum duration to suppress a stable route

The route-flap damping algorithm is compatible with RFC2439. The use of this commandis not recommended nowadays, see RIPE-378.

11.3 BGP MED

The BGP MED (Multi_Exit_Discriminator) attribute has properties which cancause subtle convergence problems in BGP. These properties and problemshave proven to be hard to understand, at least historically, and may stillnot be widely understood. The following attempts to collect together andpresent what is known about MED, to help operators and Quagga users indesigning and configuring their networks.

The BGP MED (Multi_Exit_Discriminator) attribute is intended toallow one AS to indicate its preferences for its ingress points to anotherAS. The MED attribute will not be propagated on to another AS by thereceiving AS - it is ‘non-transitive’ in the BGP sense.

E.g., if AS X and AS Y have 2 different BGP peering points, then AS Xmight set a MED of 100 on routes advertised at one and a MED of 200 at theother. When AS Y selects between otherwise equal routes to or viaAS X, AS Y should prefer to take the path via the lower MED peering of 100 withAS X. Setting the MED allows an AS to influence the routing taken to itwithin another, neighbouring AS.

In this use of MED it is not really meaningful to compare the MED value onroutes where the next AS on the paths differs. E.g., if AS Y also had aroute for some destination via AS Z in addition to the routes from AS X, andAS Z had also set a MED, it wouldn’t make sense for AS Y to compare AS Z’sMED values to those of AS X. The MED values have been set by differentadministrators, with different frames of reference.

The default behaviour of BGP therefore is to not compare MED values acrossroutes received from different neighbouring ASes. In Quagga this is done bycomparing the neighbouring, left-most AS in the received AS_PATHs of theroutes and only comparing MED if those are the same.

Unfortunately, this behaviour of MED, of sometimes being compared acrossroutes and sometimes not, depending on the properties of those other routes,means MED can cause the order of preference over all the routes to beundefined. That is, given routes A, B, and C, if A is preferred to B, and Bis preferred to C, then a well-defined order should mean the preference istransitive (in the sense of orders ²) and that A would be preferred to C.

However, when MED is involved this need not be the case. With MED it ispossible that C is actually preferred over A. So A is preferred to B, B ispreferred to C, but C is preferred to A. This can be true even where BGPdefines a deterministic “most preferred” route out of the full set ofA,B,C. With MED, for any given set of routes there may be adeterministically preferred route, but there need not be any way to arrangethem into any order of preference. With unmodified MED, the order ofpreference of routes literally becomes undefined.

That MED can induce non-transitive preferences over routes can cause issues. Firstly, it may be perceived to cause routing table churn locally atspeakers; secondly, and more seriously, it may cause routing instability iniBGP topologies, where sets of speakers continually oscillate betweendifferent paths.

The first issue arises from how speakers often implement routing decisions. Though BGP defines a selection process that will deterministically selectthe same route as best at any given speaker, even with MED, that processrequires evaluating all routes together. For performance and ease ofimplementation reasons, many implementations evaluate route preferences in apair-wise fashion instead. Given there is no well-defined order when MED isinvolved, the best route that will be chosen becomes subject toimplementation details, such as the order the routes are stored in. Thatmay be (locally) non-deterministic, e.g. it may be the order the routeswere received in.

This indeterminism may be considered undesirable, though it need not causeproblems. It may mean additional routing churn is perceived, as sometimesmore updates may be produced than at other times in reaction to some event .

This first issue can be fixed with a more deterministic route selection thatensures routes are ordered by the neighbouring AS during selection. See bgp deterministic-med. This may reduce the number of updates asroutes are received, and may in some cases reduce routing churn. Though, itcould equally deterministically produce the largest possible set of updatesin response to the most common sequence of received updates.

A deterministic order of evaluation tends to imply an additional overhead ofsorting over any set of n routes to a destination. The implementation ofdeterministic MED in Quagga scales significantly worse than most sortingalgorithms at present, with the number of paths to a given destination. That number is often low enough to not cause any issues, but where there aremany paths, the deterministic comparison may quickly become increasinglyexpensive in terms of CPU.

Deterministic local evaluation can not fix the second, more major,issue of MED however. Which is that the non-transitive preference of routesMED can cause may lead to routing instability or oscillation across multiplespeakers in iBGP topologies. This can occur with full-mesh iBGP, but isparticularly problematic in non-full-mesh iBGP topologies that furtherreduce the routing information known to each speaker. This has primarilybeen documented with iBGP route-reflection topologies. However, anyroute-hiding technologies potentially could also exacerbate oscillation withMED.

This second issue occurs where speakers each have only a subset of routes,and there are cycles in the preferences between different combinations ofroutes - as the undefined order of preference of MED allows - and the routesare distributed in a way that causes the BGP speakers to ’chase’ thosecycles. This can occur even if all speakers use a deterministic order ofevaluation in route selection.

E.g., speaker 4 in AS A might receive a route from speaker 2 in AS X, andfrom speaker 3 in AS Y; while speaker 5 in AS A might receive that routefrom speaker 1 in AS Y. AS Y might set a MED of 200 at speaker 1, and 100at speaker 3. I.e, using ASN:ID:MED to label the speakers:

           /---------------\
 X:2------|--A:4-------A:5--|-Y:1:200
 Y:3:100--|-/               |
           \---------------/

Assuming all other metrics are equal (AS_PATH, ORIGIN, 0 IGP costs), thenbased on the RFC4271 decision process speaker 4 will choose X:2 overY:3:100, based on the lower ID of 2. Speaker 4 advertises X:2 to speaker 5. Speaker 5 will continue to prefer Y:1:200 based on the ID, and advertisethis to speaker 4. Speaker 4 will now have the full set of routes, and theY:1:200 it receives from 5 will beat X:2, but when speaker 4 comparesY:1:200 to Y:3:100 the MED check now becomes active as the ASes match, andnow Y:3:100 is preferred. Speaker 4 therefore now advertises Y:3:100 to 5,which will also agrees that Y:3:100 is preferred to Y:1:200, and sowithdraws the latter route from 4. Speaker 4 now has only X:2 and Y:3:100,and X:2 beats Y:3:100, and so speaker 4 implicitly updates its route tospeaker 5 to X:2. Speaker 5 sees that Y:1:200 beats X:2 based on the ID,and advertises Y:1:200 to speaker 4, and the cycle continues.

The root cause is the lack of a clear order of preference caused by how MEDsometimes is and sometimes is not compared, leading to this cycle in thepreferences between the routes:

       /---> X:2 ---beats---> Y:3:100 --\
      |                                  |
      |                                  |
       \---beats--- Y:1:200 <---beats---/

This particular type of oscillation in full-mesh iBGP topologies can beavoided by speakers preferring already selected, external routes rather thanchoosing to update to new a route based on a post-MED metric (e.g. router-ID), at the cost of a non-deterministic selection process. Quaggaimplements this, as do many other implementations, so long as it is notoverridden by setting bgp bestpath compare-routerid, and see alsoBGP decision process, .

However, more complex and insidious cycles of oscillation are possible withiBGP route-reflection, which are not so easily avoided. These have beendocumented in various places. See, e.g., McPherson, D. and Gill, V. and Walton, D., "Border Gateway Protocol (BGP) Persistent Route OscillationCondition", IETF RFC3345, and Flavel, A. and M. Roughan, "Stableand flexible iBGP", ACM SIGCOMM 2009, and Griffin, T. and G. Wilfong, "On the correctness of IBGP configuration", ACM SIGCOMM 2002 for concrete examples and further references.

There is as of this writing no known way to use MED for its originalpurpose; and reduce routing information in iBGP topologies;and be sure to avoid the instability problems of MED due thenon-transitive routing preferences it can induce; in general on arbitrarynetworks.

There may be iBGP topology specific ways to reduce the instability risks,even while using MED, e.g. by constraining the reflection topology and bytuning IGP costs between route-reflector clusters, see RFC3345 for details. In the near future, the Add-Path extension to BGP may also solve MEDoscillation while still allowing MED to be used as intended, by distributing"best-paths per neighbour AS". This would be at the cost of distributing atleast as many routes to all speakers as a full-mesh iBGP would, if not more,while also imposing similar CPU overheads as the "Deterministic MED" featureat each Add-Path reflector.

More generally, the instability problems that MED can introduce on morecomplex, non-full-mesh, iBGP topologies may be avoided either by:

Setting bgp always-compare-med, however this allows MED to be comparedacross values set by different neighbour ASes, which may not producecoherent desirable results, of itself.
Effectively ignoring MED by setting MED to the same value (e.g. 0) usingroutemap set metric on all received routes, in combination withsetting bgp always-compare-med on all speakers. This is the simplestand most performant way to avoid MED oscillation issues, where an AS is happynot to allow neighbours to inject this problematic metric.

As MED is evaluated after the AS_PATH length check, another possible use forMED is for intra-AS steering of routes with equal AS_PATH length, as anextension of the last case above. As MED is evaluated before IGP metric,this can allow cold-potato routing to be implemented to send traffic topreferred hand-offs with neighbours, rather than the closest hand-offaccording to the IGP metric.

Note that even if action is taken to address the MED non-transitivityissues, other oscillations may still be possible. E.g., on IGP cost ifiBGP and IGP topologies are at cross-purposes with each other - see theFlavel and Roughan paper above for an example. Hence the guideline that theiBGP topology should follow the IGP topology.

BGP: bgp deterministic-med

Carry out route-selection in way that produces deterministic answerslocally, even in the face of MED and the lack of a well-defined order ofpreference it can induce on routes. Without this option the preferred routewith MED may be determined largely by the order that routes were receivedin.

Setting this option will have a performance cost that may be noticeable whenthere are many routes for each destination. Currently in Quagga it isimplemented in a way that scales poorly as the number of routes perdestination increases.

The default is that this option is not set.

Note that there are other sources of indeterminism in the route selectionprocess, specifically, the preference for older and already selected routesfrom eBGP peers, See BGP decision process.

BGP: bgp always-compare-med

Always compare the MED on routes, even when they were received fromdifferent neighbouring ASes. Setting this option makes the order ofpreference of routes more defined, and should eliminate MED inducedoscillations.

If using this option, it may also be desirable to use routemap set metric to set MED to 0 on routes received from external neighbours.

This option can be used, together with routemap set metric to use MEDas an intra-AS metric to steer equal-length AS_PATH routes to, e.g., desiredexit points.

11.4 BGP network

11.4.1 BGP route

BGP: network A.B.C.D/M

This command adds the announcement network.

router bgp 1
 network 10.0.0.0/8

This configuration example says that network 10.0.0.0/8 will beannounced to all neighbors. Some vendors’ routers don’t advertiseroutes if they aren’t present in their IGP routing tables; bgpddoesn’t care about IGP routes when announcing its routes.

BGP: no network A.B.C.D/M

11.4.2 Route Aggregation

BGP: aggregate-address A.B.C.D/M: This command specifies an aggregate address.

BGP: aggregate-address A.B.C.D/M as-set: This command specifies an aggregate address. Resulting routes includeAS set.

BGP: aggregate-address A.B.C.D/M summary-only: This command specifies an aggregate address. Aggreated routes willnot be announce.

BGP: no aggregate-address A.B.C.D/M

11.4.3 Redistribute to BGP

BGP: redistribute kernel: Redistribute kernel route to BGP process.

BGP: redistribute static: Redistribute static route to BGP process.

BGP: redistribute connected: Redistribute connected route to BGP process.

BGP: redistribute rip: Redistribute RIP route to BGP process.

BGP: redistribute ospf: Redistribute OSPF route to BGP process.

11.5 BGP Peer

11.5.1 Defining Peer

BGP: neighbor peer remote-as asn

Creates a new neighbor whose remote-as is asn. peercan be an IPv4 address or an IPv6 address.

router bgp 1
 neighbor 10.0.0.1 remote-as 2

In this case my router, in AS-1, is trying to peer with AS-2 at10.0.0.1.

This command must be the first command used when configuring a neighbor.If the remote-as is not specified, bgpd will complain like this:

can't find neighbor 10.0.0.1

11.5.2 BGP Peer commands

In a router bgp clause there are neighbor specific configurationsrequired.

BGP: neighbor peer shutdown
BGP: no neighbor peer shutdown: Shutdown the peer. We can delete the neighbor’s configuration byno neighbor peer remote-as as-number but allconfiguration of the neighbor will be deleted. When you want topreserve the configuration, but want to drop the BGP peer, use thissyntax.

BGP: neighbor peer ebgp-multihop
BGP: no neighbor peer ebgp-multihop

BGP: neighbor peer description ...
BGP: no neighbor peer description ...: Set description of the peer.

BGP: neighbor peer version version: Set up the neighbor’s BGP version. version can be 4,4+ or 4-. BGP version 4 is the default value used forBGP peering. BGP version 4+ means that the neighbor supportsMultiprotocol Extensions for BGP-4. BGP version 4- is similar butthe neighbor speaks the old Internet-Draft revision 00’s MultiprotocolExtensions for BGP-4. Some routing software is still using thisversion.

BGP: neighbor peer interface ifname

BGP: no neighbor peer interface ifname

When you connect to a BGP peer over an IPv6 link-local address, you have to specify the ifname of the interface used for the connection. To specify IPv4 session addresses, see the neighbor peer update-source command below.

This command is deprecated and may be removed in a future release. Itsuse should be avoided.

BGP: neighbor peer next-hop-self [all]
BGP: no neighbor peer next-hop-self [all]: This command specifies an announced route’s nexthop as being equivalentto the address of the bgp router if it is learned via eBGP.If the optional keyword all is specified the modifiation is donealso for routes learned via iBGP.

BGP: neighbor peer update-source <ifname|address>

BGP: no neighbor peer update-source

Specify the IPv4 source address to use for the BGP session to thisneighbour, may be specified as either an IPv4 address directly oras an interface name (in which case the zebra daemon MUST be runningin order for bgpd to be able to retrieve interface state).

router bgp 64555
 neighbor foo update-source 192.168.0.1
 neighbor bar update-source lo0

BGP: neighbor peer default-originate
BGP: no neighbor peer default-originate: bgpd’s default is to not announce the default route (0.0.0.0/0) even itis in routing table. When you want to announce default routes to thepeer, use this command.

BGP: neighbor peer port port
BGP: neighbor peer port port

BGP: neighbor peer send-community
BGP: neighbor peer send-community

BGP: neighbor peer weight weight
BGP: no neighbor peer weight weight: This command specifies a default weight value for the neighbor’sroutes.

BGP: neighbor peer maximum-prefix number
BGP: no neighbor peer maximum-prefix number

BGP: neighbor peer local-as as-number

BGP: neighbor peer local-as as-number no-prepend

BGP: neighbor peer local-as as-number no-prepend replace-as

BGP: no neighbor peer local-as

Specify an alternate AS for this BGP process when interacting with thespecified peer. With no modifiers, the specified local-as is prepended tothe received AS_PATH when receiving routing updates from the peer, andprepended to the outgoing AS_PATH (after the process local AS) whentransmitting local routes to the peer.

If the no-prepend attribute is specified, then the supplied local-as is notprepended to the received AS_PATH.

If the replace-as attribute is specified, then only the supplied local-as isprepended to the AS_PATH when transmitting local-route updates to this peer.

Note that replace-as can only be specified if no-prepend is.

This command is only allowed for eBGP peers.

BGP: neighbor peer ttl-security hops number
BGP: no neighbor peer ttl-security hops number: This command enforces Generalized TTL Security Mechanism (GTSM), asspecified in RFC 5082. With this command, only neighbors that are thespecified number of hops away will be allowed to become neighbors. Thiscommand is mututally exclusive with ebgp-multihop.

11.5.3 Peer filtering

BGP: neighbor peer distribute-list name [in|out]: This command specifies a distribute-list for the peer. direct is‘in’ or ‘out’.

BGP command: neighbor peer prefix-list name [in|out]

BGP command: neighbor peer filter-list name [in|out]

BGP: neighbor peer route-map name [in|out]: Apply a route-map on the neighbor. direct must be in orout.

BGP: bgp route-reflector allow-outbound-policy: By default, attribute modification via route-map policy out is not reflectedon reflected routes. This option allows the modifications to be reflected aswell. Once enabled, it affects all reflected routes.

11.6 BGP Peer Group

BGP: neighbor word peer-group: This command defines a new peer group.

BGP: neighbor peer peer-group word: This command bind specific peer to peer group word.

11.7 BGP Address Family

Multiprotocol BGP enables BGP to carry routing information for multipleNetwork Layer protocols. BGP supports multiple Address FamilyIdentifier (AFI), namely IPv4 and IPv6. Support is also provided formultiple sets of per-AFI information via Subsequent Address FamilyIdentifiers (SAFI). In addition to unicast information, VPN informationRFC4364 and RFC4659, and Encapsulation informationRFC5512 is supported.

Command: show ip bgp vpnv4 all
Command: show ipv6 bgp vpn all: Print active IPV4 or IPV6 routes advertised via the VPN SAFI.

Command: show ip bgp encap all
Command: show ipv6 bgp encap all: Print active IPV4 or IPV6 routes advertised via the Encapsulation SAFI.

Command: show bgp ipv4 encap summary
Command: show bgp ipv4 vpn summary
Command: show bgp ipv6 encap summary
Command: show bgp ipv6 vpn summary: Print a summary of neighbor connections for the specified AFI/SAFI combination.

11.8 Autonomous System

The AS (Autonomous System) number is one of the essentialelement of BGP. BGP is a distance vector routing protocol, and theAS-Path framework provides distance vector metric and loop detection toBGP. RFC1930, Guidelines for creation, selection, andregistration of an Autonomous System (AS) provides some background onthe concepts of an AS.

The AS number is a two octet value, ranging in value from 1 to 65535.The AS numbers 64512 through 65535 are defined as private AS numbers. Private AS numbers must not to be advertised in the global Internet.

11.8.1 AS Path Regular Expression

AS path regular expression can be used for displaying BGP routes andAS path access list. AS path regular expression is based onPOSIX 1003.2 regular expressions. Following description isjust a subset of POSIX regular expression. User can use fullPOSIX regular expression. Adding to that special character ’_’is added for AS path regular expression.

.: Matches any single character.
*: Matches 0 or more occurrences of pattern.
+: Matches 1 or more occurrences of pattern.
?: Match 0 or 1 occurrences of pattern.
^: Matches the beginning of the line.
$: Matches the end of the line.
_: Character _ has special meanings in AS path regular expression.It matches to space and comma , and AS set delimiter { and } and ASconfederation delimiter ( and ). And it also matches tothe beginning of the line and the end of the line. So _ can beused for AS value boundaries match. show ip bgp regexp _7675_matches to all of BGP routes which as AS number include 7675.

11.8.2 Display BGP Routes by AS Path

To show BGP routes which has specific AS path information showip bgp command can be used.

Command: show ip bgp regexp line: This commands display BGP routes that matches AS path regularexpression line.

11.8.3 AS Path Access List

AS path access list is user defined AS path.

Command: ip as-path access-list word {permit|deny} line: This command defines a new AS path access list.

Command: no ip as-path access-list word
Command: no ip as-path access-list word {permit|deny} line

11.8.4 Using AS Path in Route Map

Route Map: match as-path word

Route Map: set as-path prepend as-path: Prepend the given string of AS numbers to the AS_PATH.

Route Map: set as-path prepend last-as num: Prepend the existing last AS number (the leftmost ASN) to the AS_PATH.

11.8.5 Private AS Numbers

11.9 BGP Communities Attribute

BGP communities attribute is widely used for implementing policyrouting. Network operators can manipulate BGP communities attributebased on their network policy. BGP communities attribute is definedin RFC1997, BGP Communities Attribute andRFC1998, An Application of the BGP Community Attributein Multi-home Routing. It is an optional transitive attribute,therefore local policy can travel through different autonomous system.

Communities attribute is a set of communities values. Eachcommunities value is 4 octet long. The following format is used todefine communities value.

AS:VAL: This format represents 4 octet communities value. AS is highorder 2 octet in digit format. VAL is low order 2 octet indigit format. This format is useful to define AS oriented policyvalue. For example, 7675:80 can be used when AS 7675 wants topass local policy value 80 to neighboring peer.
internet: internet represents well-known communities value 0.
no-export: no-export represents well-known communities value NO_EXPORT
(0xFFFFFF01). All routes carry this value must not be advertisedto outside a BGP confederation boundary. If neighboring BGP peer ispart of BGP confederation, the peer is considered as inside a BGPconfederation boundary, so the route will be announced to the peer.
no-advertise: no-advertise represents well-known communities valueNO_ADVERTISE
(0xFFFFFF02). All routes carry this valuemust not be advertise to other BGP peers.
local-AS: local-AS represents well-known communities valueNO_EXPORT_SUBCONFED (0xFFFFFF03). All routes carry thisvalue must not be advertised to external BGP peers. Even if theneighboring router is part of confederation, it is considered asexternal BGP peer, so the route will not be announced to the peer.

When BGP communities attribute is received, duplicated communitiesvalue in the communities attribute is ignored and each communitiesvalues are sorted in numerical order.

11.9.1 BGP Community Lists

BGP community list is a user defined BGP communites attribute list.BGP community list can be used for matching or manipulating BGPcommunities attribute in updates.

There are two types of community list. One is standard communitylist and another is expanded community list. Standard community listdefines communities attribute. Expanded community list definescommunities attribute string with regular expression. Standardcommunity list is compiled into binary format when user define it.Standard community list will be directly compared to BGP communitiesattribute in BGP updates. Therefore the comparison is faster thanexpanded community list.

Command: ip community-list standard name {permit|deny} community: This command defines a new standard community list. communityis communities value. The community is compiled into communitystructure. We can define multiple community list under same name. Inthat case match will happen user defined order. Once thecommunity list matches to communities attribute in BGP updates itreturn permit or deny by the community list definition. When there isno matched entry, deny will be returned. When community isempty it matches to any routes.

Command: ip community-list expanded name {permit|deny} line: This command defines a new expanded community list. line is astring expression of communities attribute. line can includeregular expression to match communities attribute in BGP updates.

Command: no ip community-list name
Command: no ip community-list standard name
Command: no ip community-list expanded name: These commands delete community lists specified by name. All ofcommunity lists shares a single name space. So community lists can beremoved simpley specifying community lists name.

Command: show ip community-list

Command: show ip community-list name

This command display current community list information. Whenname is specified the specified community list’s information isshown.

# show ip community-list 
Named Community standard list CLIST
    permit 7675:80 7675:100 no-export
    deny internet
Named Community expanded list EXPAND
    permit :

# show ip community-list CLIST
Named Community standard list CLIST
    permit 7675:80 7675:100 no-export
    deny internet

11.9.2 Numbered BGP Community Lists

When number is used for BGP community list name, the number hasspecial meanings. Community list number in the range from 1 and 99 isstandard community list. Community list number in the range from 100to 199 is expanded community list. These community lists are calledas numbered community lists. On the other hand normal community listsis called as named community lists.

Command: ip community-list <1-99> {permit|deny} community: This command defines a new community list. <1-99> is standardcommunity list number. Community list name within this range definesstandard community list. When community is empty it matches toany routes.

Command: ip community-list <100-199> {permit|deny} community: This command defines a new community list. <100-199> is expandedcommunity list number. Community list name within this range definesexpanded community list.

Command: ip community-list name {permit|deny} community: When community list type is not specifed, the community list type isautomatically detected. If community can be compiled intocommunities attribute, the community list is defined as a standardcommunity list. Otherwise it is defined as an expanded communitylist. This feature is left for backward compability. Use of thisfeature is not recommended.

11.9.3 BGP Community in Route Map

In Route Map (see Route Map), we can match or set BGPcommunities attribute. Using this feature network operator canimplement their network policy based on BGP communities attribute.

Following commands can be used in Route Map.

Route Map: match community word
Route Map: match community word exact-match: This command perform match to BGP updates using community listword. When the one of BGP communities value match to the one ofcommunities value in community list, it is match. Whenexact-match keyword is spcified, match happen only when BGPupdates have completely same communities value specified in thecommunity list.

Route Map: set community none
Route Map: set community community
Route Map: set community community additive: This command manipulate communities value in BGP updates. Whennone is specified as communities value, it removes entirecommunities attribute from BGP updates. When community is notnone, specified communities value is set to BGP updates. IfBGP updates already has BGP communities value, the existing BGPcommunities value is replaced with specified community value.When additive keyword is specified, community is appendedto the existing communities value.

Route Map: set comm-list word delete: This command remove communities value from BGP communities attribute.The word is community list name. When BGP route’s communitiesvalue matches to the community list word, the communities valueis removed. When all of communities value is removed eventually, theBGP update’s communities attribute is completely removed.

11.9.4 Display BGP Routes by Community

To show BGP routes which has specific BGP communities attribute,show ip bgp command can be used. The community value andcommunity list can be used for show ip bgp command.

Command: show ip bgp community
Command: show ip bgp community community
Command: show ip bgp community community exact-match: show ip bgp community displays BGP routes which has communitiesattribute. When community is specified, BGP routes that matchescommunity value is displayed. For this command, internetkeyword can’t be used for community value. Whenexact-match is specified, it display only routes that have anexact match.

Command: show ip bgp community-list word
Command: show ip bgp community-list word exact-match: This commands display BGP routes that matches community listword. When exact-match is specified, display only routesthat have an exact match.

11.9.5 Using BGP Communities Attribute

Following configuration is the most typical usage of BGP communitiesattribute. AS 7675 provides upstream Internet connection to AS 100.When following configuration exists in AS 7675, AS 100 networksoperator can set local preference in AS 7675 network by setting BGPcommunities attribute to the updates.

router bgp 7675
 neighbor 192.168.0.1 remote-as 100
 neighbor 192.168.0.1 route-map RMAP in
!
ip community-list 70 permit 7675:70
ip community-list 70 deny
ip community-list 80 permit 7675:80
ip community-list 80 deny
ip community-list 90 permit 7675:90
ip community-list 90 deny
!
route-map RMAP permit 10
 match community 70
 set local-preference 70
!
route-map RMAP permit 20
 match community 80
 set local-preference 80
!
route-map RMAP permit 30
 match community 90
 set local-preference 90

Following configuration announce 10.0.0.0/8 from AS 100 to AS 7675.The route has communities value 7675:80 so when above configurationexists in AS 7675, announced route’s local preference will be set tovalue 80.

router bgp 100
 network 10.0.0.0/8
 neighbor 192.168.0.2 remote-as 7675
 neighbor 192.168.0.2 route-map RMAP out
!
ip prefix-list PLIST permit 10.0.0.0/8
!
route-map RMAP permit 10
 match ip address prefix-list PLIST
 set community 7675:80

Following configuration is an example of BGP route filtering usingcommunities attribute. This configuration only permit BGP routeswhich has BGP communities value 0:80 or 0:90. Network operator canput special internal communities value at BGP border router, thenlimit the BGP routes announcement into the internal network.

router bgp 7675
 neighbor 192.168.0.1 remote-as 100
 neighbor 192.168.0.1 route-map RMAP in
!
ip community-list 1 permit 0:80 0:90
!
route-map RMAP permit in
 match community 1

Following exmaple filter BGP routes which has communities value 1:1.When there is no match community-list returns deny. To avoidfiltering all of routes, we need to define permit any at last.

router bgp 7675
 neighbor 192.168.0.1 remote-as 100
 neighbor 192.168.0.1 route-map RMAP in
!
ip community-list standard FILTER deny 1:1
ip community-list standard FILTER permit
!
route-map RMAP permit 10
 match community FILTER

Communities value keyword internet has special meanings instandard community lists. In below example internet act asmatch any. It matches all of BGP routes even if the route does nothave communities attribute at all. So community list INTERNETis same as above example’s FILTER.

ip community-list standard INTERNET deny 1:1
ip community-list standard INTERNET permit internet

Following configuration is an example of communities value deletion.With this configuration communities value 100:1 and 100:2 is removedfrom BGP updates. For communities value deletion, only permitcommunity-list is used. deny community-list is ignored.

router bgp 7675
 neighbor 192.168.0.1 remote-as 100
 neighbor 192.168.0.1 route-map RMAP in
!
ip community-list standard DEL permit 100:1 100:2
!
route-map RMAP permit 10
 set comm-list DEL delete

11.10 BGP Extended Communities Attribute

BGP extended communities attribute is introduced with MPLS VPN/BGPtechnology. MPLS VPN/BGP expands capability of network infrastructureto provide VPN functionality. At the same time it requires a newframework for policy routing. With BGP Extended Communities Attributewe can use Route Target or Site of Origin for implementing networkpolicy for MPLS VPN/BGP.

BGP Extended Communities Attribute is similar to BGP CommunitiesAttribute. It is an optional transitive attribute. BGP ExtendedCommunities Attribute can carry multiple Extended Community value.Each Extended Community value is eight octet length.

BGP Extended Communities Attribute provides an extended rangecompared with BGP Communities Attribute. Adding to that there is atype field in each value to provides community space structure.

There are two format to define Extended Community value. One is ASbased format the other is IP address based format.

AS:VAL: This is a format to define AS based Extended Community value.AS part is 2 octets Global Administrator subfield in ExtendedCommunity value. VAL part is 4 octets Local Administratorsubfield. 7675:100 represents AS 7675 policy value 100.
IP-Address:VAL: This is a format to define IP address based Extended Community value.IP-Address part is 4 octets Global Administrator subfield.VAL part is 2 octets Local Administrator subfield.10.0.0.1:100 represents

11.10.1 BGP Extended Community Lists

Expanded Community Lists is a user defined BGP Expanded CommunityLists.

Command: ip extcommunity-list standard name {permit|deny} extcommunity: This command defines a new standard extcommunity-list.extcommunity is extended communities value. Theextcommunity is compiled into extended community structure. Wecan define multiple extcommunity-list under same name. In that casematch will happen user defined order. Once the extcommunity-listmatches to extended communities attribute in BGP updates it returnpermit or deny based upon the extcommunity-list definition. Whenthere is no matched entry, deny will be returned. Whenextcommunity is empty it matches to any routes.

Command: ip extcommunity-list expanded name {permit|deny} line: This command defines a new expanded extcommunity-list. line isa string expression of extended communities attribute. line caninclude regular expression to match extended communities attribute inBGP updates.

Command: no ip extcommunity-list name
Command: no ip extcommunity-list standard name
Command: no ip extcommunity-list expanded name: These commands delete extended community lists specified byname. All of extended community lists shares a single namespace. So extended community lists can be removed simpley specifyingthe name.

Command: show ip extcommunity-list

Command: show ip extcommunity-list name

This command display current extcommunity-list information. Whenname is specified the community list’s information is shown.

# show ip extcommunity-list

11.10.2 BGP Extended Communities in Route Map

Route Map: match extcommunity word

Route Map: set extcommunity rt extcommunity: This command set Route Target value.

Route Map: set extcommunity soo extcommunity: This command set Site of Origin value.

11.11 Displaying BGP Routes

11.11.1 Show IP BGP

Command: show ip bgp
Command: show ip bgp A.B.C.D
Command: show ip bgp X:X::X:X: This command displays BGP routes. When no route is specified itdisplay all of IPv4 BGP routes.

BGP table version is 0, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.1/32       0.0.0.0                  0         32768 i

Total number of prefixes 1

11.11.2 More Show IP BGP

Command: show ip bgp regexp line: This command display BGP routes using AS path regular expression (see Display BGP Routes by AS Path).

Command: show ip bgp community community
Command: show ip bgp community community exact-match: This command display BGP routes using community (see Display BGP Routes by Community).

Command: show ip bgp community-list word
Command: show ip bgp community-list word exact-match: This command display BGP routes using community list (see Display BGP Routes by Community).

Command: show ip bgp summary

Command: show ip bgp neighbor [peer]

Command: clear ip bgp peer: Clear peers which have addresses of X.X.X.X

Command: clear ip bgp peer soft in: Clear peer using soft reconfiguration.

Command: show ip bgp dampened-paths: Display paths suppressed due to dampening

Command: show ip bgp flap-statistics: Display flap statistics of routes

Command: show debug

Command: debug event

Command: debug update

Command: debug keepalive

Command: no debug event

Command: no debug update

Command: no debug keepalive

11.12 Capability Negotiation

When adding IPv6 routing information exchange feature to BGP. Therewere some proposals. IETF (Internet Engineering Task Force)IDR (Inter Domain Routing) WG (Working group) adopteda proposal called Multiprotocol Extension for BGP. The specificationis described in RFC2283. The protocol does not define new protocols. It defines new attributes to existing BGP. When it is used exchangingIPv6 routing information it is called BGP-4+. When it is used forexchanging multicast routing information it is called MBGP.

bgpd supports Multiprotocol Extension for BGP. So if remotepeer supports the protocol, bgpd can exchange IPv6 and/ormulticast routing information.

Traditional BGP did not have the feature to detect remote peer’scapabilities, e.g. whether it can handle prefix types other than IPv4unicast routes. This was a big problem using Multiprotocol Extensionfor BGP to operational network. RFC2842, CapabilitiesAdvertisement with BGP-4 adopted a feature called CapabilityNegotiation. bgpd use this Capability Negotiation to detectthe remote peer’s capabilities. If the peer is only configured as IPv4unicast neighbor, bgpd does not send these CapabilityNegotiation packets (at least not unless other optional BGP featuresrequire capability negotation).

By default, Quagga will bring up peering with minimal common capabilityfor the both sides. For example, local router has unicast andmulticast capabilitie and remote router has unicast capability. Inthis case, the local router will establish the connection with unicastonly capability. When there are no common capabilities, Quagga sendsUnsupported Capability error and then resets the connection.

If you want to completely match capabilities with remote peer. Pleaseuse strict-capability-match command.

BGP: neighbor peer strict-capability-match
BGP: no neighbor peer strict-capability-match: Strictly compares remote capabilities and local capabilities. If capabilitiesare different, send Unsupported Capability error then reset connection.

You may want to disable sending Capability Negotiation OPEN messageoptional parameter to the peer when remote peer does not implementCapability Negotiation. Please use dont-capability-negotiatecommand to disable the feature.

BGP: neighbor peer dont-capability-negotiate
BGP: no neighbor peer dont-capability-negotiate: Suppress sending Capability Negotiation as OPEN message optionalparameter to the peer. This command only affects the peer is configuredother than IPv4 unicast configuration.

When remote peer does not have capability negotiation feature, remotepeer will not send any capabilities at all. In that case, bgpconfigures the peer with configured capabilities.

You may prefer locally configured capabilities more than the negotiatedcapabilities even though remote peer sends capabilities. If the peeris configured by override-capability, bgpd ignoresreceived capabilities then override negotiated capabilities withconfigured values.

BGP: neighbor peer override-capability
BGP: no neighbor peer override-capability: Override the result of Capability Negotiation with local configuration.Ignore remote peer’s capability value.

11.13 Route Reflector

BGP: bgp cluster-id a.b.c.d

BGP: neighbor peer route-reflector-client
BGP: no neighbor peer route-reflector-client

11.14 Route Server

At an Internet Exchange point, many ISPs are connected to each other byexternal BGP peering. Normally these external BGP connection are done by‘full mesh’ method. As with internal BGP full mesh formation,this method has a scaling problem.

This scaling problem is well known. Route Server is a method to resolvethe problem. Each ISP’s BGP router only peers to Route Server. RouteServer serves as BGP information exchange to other BGP routers. Byapplying this method, numbers of BGP connections is reduced fromO(n*(n-1)/2) to O(n).

Unlike normal BGP router, Route Server must have several routing tablesfor managing different routing policies for each BGP speaker. We call therouting tables as different views. bgpd can work asnormal BGP router or Route Server or both at the same time.

11.14.1 Multiple instance

To enable multiple view function of bgpd, you must turn onmultiple instance feature beforehand.

Command: bgp multiple-instance: Enable BGP multiple instance feature. After this feature is enabled,you can make multiple BGP instances or multiple BGP views.

Command: no bgp multiple-instance: Disable BGP multiple instance feature. You can not disable this featurewhen BGP multiple instances or views exist.

When you want to make configuration more Cisco like one,

Command: bgp config-type cisco: Cisco compatible BGP configuration output.

When bgp config-type cisco is specified,

“no synchronization” is displayed.“no auto-summary” is displayed.

“network” and “aggregate-address” argument is displayed as“A.B.C.D M.M.M.M”

Quagga: network 10.0.0.0/8Cisco: network 10.0.0.0

Quagga: aggregate-address 192.168.0.0/24Cisco: aggregate-address 192.168.0.0 255.255.255.0

Community attribute handling is also different. If there is noconfiguration is specified community attribute and extended communityattribute are sent to neighbor. When user manually disable thefeature community attribute is not sent to the neighbor. In case ofbgp config-type cisco is specified, community attribute is notsent to the neighbor by default. To send community attribute user hasto specify neighbor A.B.C.D send-community command.

!
router bgp 1
 neighbor 10.0.0.1 remote-as 1
 no neighbor 10.0.0.1 send-community
!
router bgp 1
 neighbor 10.0.0.1 remote-as 1
 neighbor 10.0.0.1 send-community
!

Command: bgp config-type zebra: Quagga style BGP configuration. This is default.

11.14.2 BGP instance and view

BGP instance is a normal BGP process. The result of route selectiongoes to the kernel routing table. You can setup different AS at thesame time when BGP multiple instance feature is enabled.

Command: router bgp as-number: Make a new BGP instance. You can use arbitrary word for the name.

bgp multiple-instance
!
router bgp 1
 neighbor 10.0.0.1 remote-as 2
 neighbor 10.0.0.2 remote-as 3
!
router bgp 2
 neighbor 10.0.0.3 remote-as 4
 neighbor 10.0.0.4 remote-as 5

BGP view is almost same as normal BGP process. The result ofroute selection does not go to the kernel routing table. BGP view isonly for exchanging BGP routing information.

Command: router bgp as-number view name: Make a new BGP view. You can use arbitrary word for the name. Thisview’s route selection result does not go to the kernel routing table.

With this command, you can setup Route Server like below.

bgp multiple-instance
!
router bgp 1 view 1
 neighbor 10.0.0.1 remote-as 2
 neighbor 10.0.0.2 remote-as 3
!
router bgp 2 view 2
 neighbor 10.0.0.3 remote-as 4
 neighbor 10.0.0.4 remote-as 5

11.14.3 Routing policy

You can set different routing policy for a peer. For example, you canset different filter for a peer.

bgp multiple-instance
!
router bgp 1 view 1
 neighbor 10.0.0.1 remote-as 2
 neighbor 10.0.0.1 distribute-list 1 in
!
router bgp 1 view 2
 neighbor 10.0.0.1 remote-as 2
 neighbor 10.0.0.1 distribute-list 2 in

This means BGP update from a peer 10.0.0.1 goes to both BGP view 1 and view2. When the update is inserted into view 1, distribute-list 1 isapplied. On the other hand, when the update is inserted into view 2,distribute-list 2 is applied.

11.14.4 Viewing the view

To display routing table of BGP view, you must specify view name.

Command: show ip bgp view name: Display routing table of BGP view name.

11.15 How to set up a 6-Bone connection

zebra configuration 
=================== 
!  
! Actually there is no need to configure zebra 
!

bgpd configuration
==================
!
! This means that routes go through zebra and into the kernel.
!
router zebra
!
! MP-BGP configuration
!
router bgp 7675
 bgp router-id 10.0.0.1
 neighbor 3ffe:1cfa:0:2:2a0:c9ff:fe9e:f56 remote-as as-number
!
 address-family ipv6
 network 3ffe:506::/32
 neighbor 3ffe:1cfa:0:2:2a0:c9ff:fe9e:f56 activate
 neighbor 3ffe:1cfa:0:2:2a0:c9ff:fe9e:f56 route-map set-nexthop out
 neighbor 3ffe:1cfa:0:2:2c0:4fff:fe68:a231 remote-as as-number
 neighbor 3ffe:1cfa:0:2:2c0:4fff:fe68:a231 route-map set-nexthop out
 exit-address-family
!
ipv6 access-list all permit any
!
! Set output nexthop address.
!
route-map set-nexthop permit 10
 match ipv6 address all
 set ipv6 nexthop global 3ffe:1cfa:0:2:2c0:4fff:fe68:a225
 set ipv6 nexthop local fe80::2c0:4fff:fe68:a225
!
! logfile FILENAME is obsolete.  Please use log file FILENAME

log file bgpd.log
!

11.16 Dump BGP packets and table

Command: dump bgp all path [interval]
Command: dump bgp all-et path [interval]
Command: no dump bgp all [path] [interval]: Dump all BGP packet and events to path file.If interval is set, a new file will be created for echo interval of seconds.The path path can be set with date and time formatting (strftime).The type â€˜all-etâ€™ enables support for Extended Timestamp Header (see Packet Binary Dump Format).(see Packet Binary Dump Format)

Command: dump bgp updates path [interval]
Command: dump bgp updates-et path [interval]
Command: no dump bgp updates [path] [interval]: Dump only BGP updates messages to path file.If interval is set, a new file will be created for echo interval of seconds.The path path can be set with date and time formatting (strftime).The type â€˜updates-etâ€™ enables support for Extended Timestamp Header (see Packet Binary Dump Format).

Command: dump bgp routes-mrt path
Command: dump bgp routes-mrt path interval
Command: no dump bgp route-mrt [path] [interval]: Dump whole BGP routing table to path. This is heavy process.The path path can be set with date and time formatting (strftime).If interval is set, a new file will be created for echo interval of seconds.

Note: the interval variable can also be set using hours and minutes: 04h20m00.

11.17 BGP Configuration Examples

Example of a session to an upstream, advertising only one prefix to it.

router bgp 64512
 bgp router-id 10.236.87.1
 network 10.236.87.0/24
 neighbor upstream peer-group
 neighbor upstream remote-as 64515
 neighbor upstream capability dynamic
 neighbor upstream prefix-list pl-allowed-adv out
 neighbor 10.1.1.1 peer-group upstream
 neighbor 10.1.1.1 description ACME ISP
!
ip prefix-list pl-allowed-adv seq 5 permit 82.195.133.0/25
ip prefix-list pl-allowed-adv seq 10 deny any

A more complex example. With upstream, peer and customer sessions.Advertising global prefixes and NO_EXPORT prefixes and providingactions for customer routes based on community values. Extensive use ofroute-maps and the ’call’ feature to support selective advertising ofprefixes. This example is intended as guidance only, it has NOT beentested and almost certainly containts silly mistakes, if not seriousflaws.

router bgp 64512
 bgp router-id 10.236.87.1
 network 10.123.456.0/24
 network 10.123.456.128/25 route-map rm-no-export
 neighbor upstream capability dynamic
 neighbor upstream route-map rm-upstream-out out
 neighbor cust capability dynamic
 neighbor cust route-map rm-cust-in in
 neighbor cust route-map rm-cust-out out
 neighbor cust send-community both
 neighbor peer capability dynamic
 neighbor peer route-map rm-peer-in in
 neighbor peer route-map rm-peer-out out
 neighbor peer send-community both
 neighbor 10.1.1.1 remote-as 64515
 neighbor 10.1.1.1 peer-group upstream
 neighbor 10.2.1.1 remote-as 64516
 neighbor 10.2.1.1 peer-group upstream
 neighbor 10.3.1.1 remote-as 64517
 neighbor 10.3.1.1 peer-group cust-default
 neighbor 10.3.1.1 description customer1
 neighbor 10.3.1.1 prefix-list pl-cust1-network in
 neighbor 10.4.1.1 remote-as 64518
 neighbor 10.4.1.1 peer-group cust
 neighbor 10.4.1.1 prefix-list pl-cust2-network in
 neighbor 10.4.1.1 description customer2
 neighbor 10.5.1.1 remote-as 64519
 neighbor 10.5.1.1 peer-group peer
 neighbor 10.5.1.1 prefix-list pl-peer1-network in
 neighbor 10.5.1.1 description peer AS 1
 neighbor 10.6.1.1 remote-as 64520
 neighbor 10.6.1.1 peer-group peer
 neighbor 10.6.1.1 prefix-list pl-peer2-network in
 neighbor 10.6.1.1 description peer AS 2
!
ip prefix-list pl-default permit 0.0.0.0/0
!
ip prefix-list pl-upstream-peers permit 10.1.1.1/32
ip prefix-list pl-upstream-peers permit 10.2.1.1/32
!
ip prefix-list pl-cust1-network permit 10.3.1.0/24
ip prefix-list pl-cust1-network permit 10.3.2.0/24
!
ip prefix-list pl-cust2-network permit 10.4.1.0/24
!
ip prefix-list pl-peer1-network permit 10.5.1.0/24
ip prefix-list pl-peer1-network permit 10.5.2.0/24
ip prefix-list pl-peer1-network permit 192.168.0.0/24
!
ip prefix-list pl-peer2-network permit 10.6.1.0/24
ip prefix-list pl-peer2-network permit 10.6.2.0/24
ip prefix-list pl-peer2-network permit 192.168.1.0/24
ip prefix-list pl-peer2-network permit 192.168.2.0/24
ip prefix-list pl-peer2-network permit 172.16.1/24
!
ip as-path access-list asp-own-as permit ^$
ip as-path access-list asp-own-as permit _64512_
!
! #################################################################
! Match communities we provide actions for, on routes receives from
! customers. Communities values of <our-ASN>:X, with X, have actions:
!
! 100 - blackhole the prefix
! 200 - set no_export
! 300 - advertise only to other customers
! 400 - advertise only to upstreams
! 500 - set no_export when advertising to upstreams
! 2X00 - set local_preference to X00
!
! blackhole the prefix of the route
ip community-list standard cm-blackhole permit 64512:100
!
! set no-export community before advertising
ip community-list standard cm-set-no-export permit 64512:200
!
! advertise only to other customers
ip community-list standard cm-cust-only permit 64512:300
!
! advertise only to upstreams
ip community-list standard cm-upstream-only permit 64512:400
!
! advertise to upstreams with no-export
ip community-list standard cm-upstream-noexport permit 64512:500
!
! set local-pref to least significant 3 digits of the community
ip community-list standard cm-prefmod-100 permit 64512:2100
ip community-list standard cm-prefmod-200 permit 64512:2200
ip community-list standard cm-prefmod-300 permit 64512:2300
ip community-list standard cm-prefmod-400 permit 64512:2400
ip community-list expanded cme-prefmod-range permit 64512:2...
!
! Informational communities
!
! 3000 - learned from upstream
! 3100 - learned from customer
! 3200 - learned from peer
!
ip community-list standard cm-learnt-upstream permit 64512:3000
ip community-list standard cm-learnt-cust permit 64512:3100
ip community-list standard cm-learnt-peer permit 64512:3200
!
! ###################################################################
! Utility route-maps
!
! These utility route-maps generally should not used to permit/deny
! routes, i.e. they do not have meaning as filters, and hence probably
! should be used with 'on-match next'. These all finish with an empty
! permit entry so as not interfere with processing in the caller.
!
route-map rm-no-export permit 10
 set community additive no-export
route-map rm-no-export permit 20
!
route-map rm-blackhole permit 10
 description blackhole, up-pref and ensure it cant escape this AS
 set ip next-hop 127.0.0.1
 set local-preference 10
 set community additive no-export
route-map rm-blackhole permit 20
!
! Set local-pref as requested
route-map rm-prefmod permit 10
 match community cm-prefmod-100
 set local-preference 100
route-map rm-prefmod permit 20
 match community cm-prefmod-200
 set local-preference 200
route-map rm-prefmod permit 30
 match community cm-prefmod-300
 set local-preference 300
route-map rm-prefmod permit 40
 match community cm-prefmod-400
 set local-preference 400
route-map rm-prefmod permit 50
!
! Community actions to take on receipt of route.
route-map rm-community-in permit 10
 description check for blackholing, no point continuing if it matches.
 match community cm-blackhole
 call rm-blackhole
route-map rm-community-in permit 20
 match community cm-set-no-export
 call rm-no-export
 on-match next
route-map rm-community-in permit 30
 match community cme-prefmod-range
 call rm-prefmod
route-map rm-community-in permit 40
!
! #####################################################################
! Community actions to take when advertising a route.
! These are filtering route-maps, 
!
! Deny customer routes to upstream with cust-only set.
route-map rm-community-filt-to-upstream deny 10
 match community cm-learnt-cust
 match community cm-cust-only
route-map rm-community-filt-to-upstream permit 20
!
! Deny customer routes to other customers with upstream-only set.
route-map rm-community-filt-to-cust deny 10
 match community cm-learnt-cust
 match community cm-upstream-only
route-map rm-community-filt-to-cust permit 20
!
! ###################################################################
! The top-level route-maps applied to sessions. Further entries could
! be added obviously..
!
! Customers
route-map rm-cust-in permit 10
 call rm-community-in
 on-match next
route-map rm-cust-in permit 20
 set community additive 64512:3100
route-map rm-cust-in permit 30
!
route-map rm-cust-out permit 10
 call rm-community-filt-to-cust
 on-match next
route-map rm-cust-out permit 20
!
! Upstream transit ASes
route-map rm-upstream-out permit 10
 description filter customer prefixes which are marked cust-only
 call rm-community-filt-to-upstream
 on-match next
route-map rm-upstream-out permit 20
 description only customer routes are provided to upstreams/peers
 match community cm-learnt-cust
!
! Peer ASes
! outbound policy is same as for upstream
route-map rm-peer-out permit 10
 call rm-upstream-out
!
route-map rm-peer-in permit 10
 set community additive 64512:3200

12 Configuring Quagga as a Route Server

The purpose of a Route Server is to centralize the peerings between BGPspeakers. For example if we have an exchange point scenario with four BGPspeakers, each of which maintaining a BGP peering with the other threewe can convert it into a centralized scenario whereeach of the four establishes a single BGP peering against the Route Server.

We will first describe briefly the Route Server model implemented by Quagga.We will explain the commands that have been added for configuring thatmodel. And finally we will show a full example of Quagga configured as RouteServer.

12.1 Description of the Route Server model

First we are going to describe the normal processing that BGP announcementssuffer inside a standard BGP speaker, as shown in Figure 12.1,it consists of three steps:

When an announcement is received from some peer, the ‘In’ filtersconfigured for that peer are applied to the announcement. These filters canreject the announcement, accept it unmodified, or accept it with some of itsattributes modified.
The announcements that pass the ‘In’ filters go into theBest Path Selection process, where they are compared to otherannouncements referred to the same destination that have beenreceived from different peers (in case such otherannouncements exist). For each different destination, the announcementwhich is selected as the best is inserted into the BGP speaker’s Loc-RIB.
The routes which are inserted in the Loc-RIB areconsidered for announcement to all the peers (except the onefrom which the route came). This is done by passing the routesin the Loc-RIB through the ‘Out’ filters corresponding to eachpeer. These filters can reject the route,accept it unmodified, or accept it with some of its attributesmodified. Those routes which are accepted by the ‘Out’ filtersof a peer are announced to that peer.

Figure 12.1: Announcement processing inside a “normal” BGP speaker

Of course we want that the routing tables obtained in each of the routersare the same when using the route server than when not. But as a consequenceof having a single BGP peering (against the route server), the BGP speakerscan no longer distinguish from/to which peer each announce comes/goes.This means that the routers connected to the routeserver are not able to apply by themselves the same input/output filtersas in the full mesh scenario, so they have to delegate those functions tothe route server.

Even more, the “best path” selection must be also performed insidethe route server on behalf of its clients. The reason is that if, afterapplying the filters of the announcer and the (potential) receiver, theroute server decides to send to some client two or more differentannouncements referred to the same destination, the client will onlyretain the last one, considering it as an implicit withdrawal of theprevious announcements for the same destination. This is the expectedbehavior of a BGP speaker as defined in RFC1771, and even thoughthere are some proposals of mechanisms that permit multiple paths forthe same destination to be sent through a single BGP peering, none arecurrently supported by most existing BGP implementations.

As a consequence a route server must maintain additional information andperform additional tasks for a RS-client that those necessary for common BGPpeerings. Essentially a route server must:

Maintain a separated Routing Information Base (Loc-RIB)for each peer configured as RS-client, containing the routesselected as a result of the “Best Path Selection” processthat is performed on behalf of that RS-client.
Whenever it receives an announcement from a RS-client,it must consider it for the Loc-RIBs of the other RS-clients.
- This means that for each of them the route server must pass theannouncement through the appropriate ‘Out’ filter of theannouncer.
- Then through the appropriate ‘In’ filter ofthe potential receiver.
- Only if the announcement is accepted by both filters it will be passedto the “Best Path Selection” process.
- Finally, it might go into the Loc-RIB of the receiver.

When we talk about the “appropriate” filter, both the announcer and thereceiver of the route must be taken into account. Suppose that the routeserver receives an announcement from client A, and the route server isconsidering it for the Loc-RIB of client B. The filters that should beapplied are the same that would be used in the full mesh scenario, i.e.,first the ‘Out’ filter of router A for announcements going to router B, andthen the ‘In’ filter of router B for announcements coming from router A.

We call “Export Policy” of a RS-client to the set of ‘Out’ filters thatthe client would use if there was no route server. The same applies for the“Import Policy” of a RS-client and the set of ‘In’ filters of the clientif there was no route server.

It is also common to demand from a route server that it does notmodify some BGP attributes (next-hop, as-path and MED) that are usuallymodified by standard BGP speakers before announcing a route.

The announcement processing model implemented by Quagga is shown inFigure 12.2. The figure shows a mixture of RS-clients (B, C and D)with normal BGP peers (A). There are some details that worth additionalcomments:

Announcements coming from a normal BGP peer are alsoconsidered for the Loc-RIBs of all the RS-clients. Butlogically they do not pass through any export policy.
Those peers that are configured as RS-clients do notreceive any announce from the ‘Main’ Loc-RIB.
Apart from import and export policies,‘In’ and ‘Out’ filters can also be set for RS-clients. ‘In’filters might be useful when the route server has also normalBGP peers. On the other hand, ‘Out’ filters for RS-clients areprobably unnecessary, but we decided not to remove them asthey do not hurt anybody (they can always be left empty).

Figure 12.2: Announcement processing model implemented by the Route Server

12.2 Commands for configuring a Route Server

Now we will describe the commands that have been added to quaggain order to support the route server features.

Route-Server: neighbor peer-group route-server-client

Route-Server: neighbor A.B.C.D route-server-client

Route-Server: neighbor X:X::X:X route-server-client

This command configures the peer given by peer, A.B.C.D orX:X::X:X as an RS-client.

Actually this command is not new, it already existed in standard Quagga. Itenables the transparent mode for the specified peer. This means that someBGP attributes (as-path, next-hop and MED) of the routes announced to thatpeer are not modified.

With the route server patch, this command, apart from setting thetransparent mode, creates a new Loc-RIB dedicated to the specified peer(those named ‘Loc-RIB for X’ in Figure 12.2.). Starting fromthat moment, every announcement received by the route server will be alsoconsidered for the new Loc-RIB.

Route-Server: neigbor {A.B.C.D|X.X::X.X|peer-group} route-map WORD {import|export}: This set of commands can be used to specify the route-map thatrepresents the Import or Export policy of a peer which isconfigured as a RS-client (with the previous command).

Route-Server: match peer {A.B.C.D|X:X::X:X}

This is a new match statement for use in route-maps, enabling them todescribe import/export policies. As we said before, an import/export policyrepresents a set of input/output filters of the RS-client. This statementmakes possible that a single route-map represents the full set of filtersthat a BGP speaker would use for its different peers in a non-RS scenario.

The match peer statement has different semantics whether it is usedinside an import or an export route-map. In the first case the statementmatches if the address of the peer who sends the announce is the same thatthe address specified by {A.B.C.D|X:X::X:X}. For export route-maps itmatches when {A.B.C.D|X:X::X:X} is the address of the RS-Client into whoseLoc-RIB the announce is going to be inserted (how the same export policy isapplied before different Loc-RIBs is shown in Figure 12.2.).

Route-map Command: call WORD: This command (also used inside a route-map) jumps into a differentroute-map, whose name is specified by WORD. When the calledroute-map finishes, depending on its result the original route-mapcontinues or not. Apart from being useful for making import/exportroute-maps easier to write, this command can also be used insideany normal (in or out) route-map.

12.3 Example of Route Server Configuration

Finally we are going to show how to configure a Quagga daemon to act as aRoute Server. For this purpose we are going to present a scenario withoutroute server, and then we will show how to use the configurations of the BGProuters to generate the configuration of the route server.

All the configuration files shown in this section have been takenfrom scenarios which were tested using the VNUML toolVNUML.

12.3.1 Configuration of the BGP routers without Route Server

We will suppose that our initial scenario is an exchange point with threeBGP capable routers, named RA, RB and RC. Each of the BGP speakers generatessome routes (with the network command), and establishes BGP peeringsagainst the other two routers. These peerings have In and Out route-mapsconfigured, named like “PEER-X-IN” or “PEER-X-OUT”. For example theconfiguration file for router RA could be the following:

#Configuration for router 'RA'
!
hostname RA
password ****
!
router bgp 65001
  no bgp default ipv4-unicast
  neighbor 2001:0DB8::B remote-as 65002
  neighbor 2001:0DB8::C remote-as 65003
!
  address-family ipv6
    network 2001:0DB8:AAAA:1::/64
    network 2001:0DB8:AAAA:2::/64
    network 2001:0DB8:0000:1::/64
    network 2001:0DB8:0000:2::/64

    neighbor 2001:0DB8::B activate
    neighbor 2001:0DB8::B soft-reconfiguration inbound
    neighbor 2001:0DB8::B route-map PEER-B-IN in
    neighbor 2001:0DB8::B route-map PEER-B-OUT out

    neighbor 2001:0DB8::C activate
    neighbor 2001:0DB8::C soft-reconfiguration inbound
    neighbor 2001:0DB8::C route-map PEER-C-IN in
    neighbor 2001:0DB8::C route-map PEER-C-OUT out
  exit-address-family
!
ipv6 prefix-list COMMON-PREFIXES seq  5 permit 2001:0DB8:0000::/48 ge 64 le 64
ipv6 prefix-list COMMON-PREFIXES seq 10 deny any
!
ipv6 prefix-list PEER-A-PREFIXES seq  5 permit 2001:0DB8:AAAA::/48 ge 64 le 64
ipv6 prefix-list PEER-A-PREFIXES seq 10 deny any
!
ipv6 prefix-list PEER-B-PREFIXES seq  5 permit 2001:0DB8:BBBB::/48 ge 64 le 64
ipv6 prefix-list PEER-B-PREFIXES seq 10 deny any
!
ipv6 prefix-list PEER-C-PREFIXES seq  5 permit 2001:0DB8:CCCC::/48 ge 64 le 64
ipv6 prefix-list PEER-C-PREFIXES seq 10 deny any
!
route-map PEER-B-IN permit 10
  match ipv6 address prefix-list COMMON-PREFIXES
  set metric 100
route-map PEER-B-IN permit 20
  match ipv6 address prefix-list PEER-B-PREFIXES
  set community 65001:11111
!
route-map PEER-C-IN permit 10
  match ipv6 address prefix-list COMMON-PREFIXES
  set metric 200
route-map PEER-C-IN permit 20
  match ipv6 address prefix-list PEER-C-PREFIXES
  set community 65001:22222
!
route-map PEER-B-OUT permit 10
  match ipv6 address prefix-list PEER-A-PREFIXES
!
route-map PEER-C-OUT permit 10
  match ipv6 address prefix-list PEER-A-PREFIXES
!
line vty
!

12.3.2 Configuration of the BGP routers with Route Server

To convert the initial scenario into one with route server, first we mustmodify the configuration of routers RA, RB and RC. Now they must not peerbetween them, but only with the route server. For example, RA’sconfiguration would turn into:

# Configuration for router 'RA'
!
hostname RA
password ****
!
router bgp 65001
  no bgp default ipv4-unicast
  neighbor 2001:0DB8::FFFF remote-as 65000
!
  address-family ipv6
    network 2001:0DB8:AAAA:1::/64
    network 2001:0DB8:AAAA:2::/64
    network 2001:0DB8:0000:1::/64
    network 2001:0DB8:0000:2::/64

    neighbor 2001:0DB8::FFFF activate
    neighbor 2001:0DB8::FFFF soft-reconfiguration inbound
  exit-address-family
!
line vty
!

Which is logically much simpler than its initial configuration, as it nowmaintains only one BGP peering and all the filters (route-maps) havedisappeared.

12.3.3 Configuration of the Route Server itself

As we said when we described the functions of a route server(see Description of the Route Server model), it is in charge of all theroute filtering. To achieve that, the In and Out filters from the RA, RB andRC configurations must be converted into Import and Export policies in theroute server.

This is a fragment of the route server configuration (we only showthe policies for client RA):

# Configuration for Route Server ('RS')
!
hostname RS
password ix
!
bgp multiple-instance
!
router bgp 65000 view RS
  no bgp default ipv4-unicast
  neighbor 2001:0DB8::A  remote-as 65001
  neighbor 2001:0DB8::B  remote-as 65002
  neighbor 2001:0DB8::C  remote-as 65003
!
  address-family ipv6
    neighbor 2001:0DB8::A activate
    neighbor 2001:0DB8::A route-server-client
    neighbor 2001:0DB8::A route-map RSCLIENT-A-IMPORT import
    neighbor 2001:0DB8::A route-map RSCLIENT-A-EXPORT export
    neighbor 2001:0DB8::A soft-reconfiguration inbound

    neighbor 2001:0DB8::B activate
    neighbor 2001:0DB8::B route-server-client
    neighbor 2001:0DB8::B route-map RSCLIENT-B-IMPORT import
    neighbor 2001:0DB8::B route-map RSCLIENT-B-EXPORT export
    neighbor 2001:0DB8::B soft-reconfiguration inbound

    neighbor 2001:0DB8::C activate
    neighbor 2001:0DB8::C route-server-client
    neighbor 2001:0DB8::C route-map RSCLIENT-C-IMPORT import
    neighbor 2001:0DB8::C route-map RSCLIENT-C-EXPORT export
    neighbor 2001:0DB8::C soft-reconfiguration inbound
  exit-address-family
!
ipv6 prefix-list COMMON-PREFIXES seq  5 permit 2001:0DB8:0000::/48 ge 64 le 64
ipv6 prefix-list COMMON-PREFIXES seq 10 deny any
!
ipv6 prefix-list PEER-A-PREFIXES seq  5 permit 2001:0DB8:AAAA::/48 ge 64 le 64
ipv6 prefix-list PEER-A-PREFIXES seq 10 deny any
!
ipv6 prefix-list PEER-B-PREFIXES seq  5 permit 2001:0DB8:BBBB::/48 ge 64 le 64
ipv6 prefix-list PEER-B-PREFIXES seq 10 deny any
!
ipv6 prefix-list PEER-C-PREFIXES seq  5 permit 2001:0DB8:CCCC::/48 ge 64 le 64
ipv6 prefix-list PEER-C-PREFIXES seq 10 deny any
!
route-map RSCLIENT-A-IMPORT permit 10
  match peer 2001:0DB8::B
  call A-IMPORT-FROM-B
route-map RSCLIENT-A-IMPORT permit 20
  match peer 2001:0DB8::C
  call A-IMPORT-FROM-C
!
route-map A-IMPORT-FROM-B permit 10
  match ipv6 address prefix-list COMMON-PREFIXES
  set metric 100
route-map A-IMPORT-FROM-B permit 20
  match ipv6 address prefix-list PEER-B-PREFIXES
  set community 65001:11111
!
route-map A-IMPORT-FROM-C permit 10
  match ipv6 address prefix-list COMMON-PREFIXES
  set metric 200
route-map A-IMPORT-FROM-C permit 20
  match ipv6 address prefix-list PEER-C-PREFIXES
  set community 65001:22222
!
route-map RSCLIENT-A-EXPORT permit 10
  match peer 2001:0DB8::B
  match ipv6 address prefix-list PEER-A-PREFIXES
route-map RSCLIENT-A-EXPORT permit 20
  match peer 2001:0DB8::C
  match ipv6 address prefix-list PEER-A-PREFIXES
!
...
...
...

If you compare the initial configuration of RA with the route serverconfiguration above, you can see how easy it is to generate the Import andExport policies for RA from the In and Out route-maps of RA’s originalconfiguration.

When there was no route server, RA maintained two peerings, one with RB andanother with RC. Each of this peerings had an In route-map configured. Tobuild the Import route-map for client RA in the route server, simply addroute-map entries following this scheme:

route-map <NAME> permit 10
    match peer <Peer Address>
    call <In Route-Map for this Peer>
route-map <NAME> permit 20
    match peer <Another Peer Address>
    call <In Route-Map for this Peer>

This is exactly the process that has been followed to generate the route-mapRSCLIENT-A-IMPORT. The route-maps that are called inside it (A-IMPORT-FROM-Band A-IMPORT-FROM-C) are exactly the same than the In route-maps from theoriginal configuration of RA (PEER-B-IN and PEER-C-IN), only the name isdifferent.

The same could have been done to create the Export policy for RA (route-mapRSCLIENT-A-EXPORT), but in this case the original Out route-maps where sosimple that we decided not to use the call WORD commands, and weintegrated all in a single route-map (RSCLIENT-A-EXPORT).

The Import and Export policies for RB and RC are not shown, butthe process would be identical.

12.3.4 Further considerations about Import and Export route-maps

The current version of the route server patch only allows to specify aroute-map for import and export policies, while in a standard BGP speakerapart from route-maps there are other tools for performing input and outputfiltering (access-lists, community-lists, ...). But this does not representany limitation, as all kinds of filters can be included in import/exportroute-maps. For example suppose that in the non-route-server scenario peerRA had the following filters configured for input from peer B:

    neighbor 2001:0DB8::B prefix-list LIST-1 in
    neighbor 2001:0DB8::B filter-list LIST-2 in
    neighbor 2001:0DB8::B route-map PEER-B-IN in
    ...
    ...
route-map PEER-B-IN permit 10
  match ipv6 address prefix-list COMMON-PREFIXES
  set local-preference 100
route-map PEER-B-IN permit 20
  match ipv6 address prefix-list PEER-B-PREFIXES
  set community 65001:11111

It is posible to write a single route-map which is equivalent tothe three filters (the community-list, the prefix-list and theroute-map). That route-map can then be used inside the Importpolicy in the route server. Lets see how to do it:

    neighbor 2001:0DB8::A route-map RSCLIENT-A-IMPORT import
    ...
!
...
route-map RSCLIENT-A-IMPORT permit 10
  match peer 2001:0DB8::B
  call A-IMPORT-FROM-B
...
...
!
route-map A-IMPORT-FROM-B permit 1
  match ipv6 address prefix-list LIST-1
  match as-path LIST-2
  on-match goto 10
route-map A-IMPORT-FROM-B deny 2
route-map A-IMPORT-FROM-B permit 10
  match ipv6 address prefix-list COMMON-PREFIXES
  set local-preference 100
route-map A-IMPORT-FROM-B permit 20
  match ipv6 address prefix-list PEER-B-PREFIXES
  set community 65001:11111
!
...
...

The route-map A-IMPORT-FROM-B is equivalent to the three filters(LIST-1, LIST-2 and PEER-B-IN). The first entry of route-mapA-IMPORT-FROM-B (sequence number 1) matches if and only if boththe prefix-list LIST-1 and the filter-list LIST-2 match. If thathappens, due to the “on-match goto 10” statement the nextroute-map entry to be processed will be number 10, and as of thatpoint route-map A-IMPORT-FROM-B is identical to PEER-B-IN. Ifthe first entry does not match, ‘on-match goto 10” will beignored and the next processed entry will be number 2, which willdeny the route.

Thus, the result is the same that with the three original filters,i.e., if either LIST-1 or LIST-2 rejects the route, it does notreach the route-map PEER-B-IN. In case both LIST-1 and LIST-2accept the route, it passes to PEER-B-IN, which can reject, acceptor modify the route.

13 VTY shell

vtysh is integrated shell of Quagga software.

To use vtysh please specify —enable-vtysh to configure script. To usePAM for authentication use —with-libpam option to configure script.

vtysh only searches /etc/quagga path for vtysh.conf whichis the vtysh configuration file. Vtysh does not search currentdirectory for configuration file because the file includes userauthentication settings.

Currently, vtysh.conf has only two commands.

13.1 VTY shell username

Command: username username nopassword

With this set, user foo does not need password authentication for user vtysh.With PAM vtysh uses PAM authentication mechanism.

If vtysh is compiled without PAM authentication, every user can use vtyshwithout authentication. vtysh requires read/write permissionto the various daemons vty sockets, this can be accomplished through useof unix groups and the –enable-vty-group configure option.

13.2 VTY shell integrated configuration

Command: service integrated-vtysh-config

Write out integrated Quagga.conf file when ’write file’ is issued.

This command controls the behaviour of vtysh when it is told to write outthe configuration. Per default, vtysh will instruct each daemon to writeout their own config files when write file is issued. However, ifservice integrated-vtysh-config is set, when write fileis issued, vtysh will instruct the daemons will write out a Quagga.conf withall daemons’ commands integrated into it.

Vtysh per default behaves as if write-conf daemon is set. Notethat both may be set at same time if one wishes to have both Quagga.conf anddaemon specific files written out. Further, note that the daemons arehard-coded to first look for the integrated Quagga.conf file before lookingfor their own file.

We recommend you do not mix the use of the two types of files. Further, itis better not to use the integrated Quagga.conf file, as any syntax error init can lead to /all/ of your daemons being unable to start up. Per daemonfiles are more robust as impact of errors in configuration are limited tothe daemon in whose file the error is made.

14 Filtering

Quagga provides many very flexible filtering features. Filtering is usedfor both input and output of the routing information. Once filtering isdefined, it can be applied in any direction.

14.1 IP Access List

Command: access-list name permit ipv4-network
Command: access-list name deny ipv4-network

Basic filtering is done by access-list as shown in thefollowing example.

access-list filter deny 10.0.0.0/9
access-list filter permit 10.0.0.0/8

14.2 IP Prefix List

ip prefix-list provides the most powerful prefix basedfiltering mechanism. In addition to access-list functionality,ip prefix-list has prefix length range specification andsequential number specification. You can add or delete prefix basedfilters to arbitrary points of prefix-list using sequential number specification.

If no ip prefix-list is specified, it acts as permit. If ip prefix-list is defined, and no match is found, default deny is applied.

Command: ip prefix-list name (permit|deny) prefix [le len] [ge len]

Command: ip prefix-list name seq number (permit|deny) prefix [le len] [ge len]

You can create ip prefix-list using above commands.

seq: seq number can be set either automatically or manually. In thecase that sequential numbers are set manually, the user may pick anynumber less than 4294967295. In the case that sequential number are setautomatically, the sequential number will increase by a unit of five (5)per list. If a list with no specified sequential number is createdafter a list with a specified sequential number, the list willautomatically pick the next multiple of five (5) as the list number.For example, if a list with number 2 already exists and a new list withno specified number is created, the next list will be numbered 5. Iflists 2 and 7 already exist and a new list with no specified number iscreated, the new list will be numbered 10.
le: le command specifies prefix length. The prefix list will be applied if the prefix length is less than or equal to the le prefix length.
ge: ge command specifies prefix length. The prefix list will be applied if the prefix length is greater than or equal to the ge prefix length.

Less than or equal to prefix numbers and greater than or equal toprefix numbers can be used together. The order of the le and gecommands does not matter.

If a prefix list with a different sequential number but with the exactsame rules as a previous list is created, an error will result.However, in the case that the sequential number and the rules areexactly similar, no error will result.

If a list with the same sequential number as a previous list is created,the new list will overwrite the old list.

Matching of IP Prefix is performed from the smaller sequential number to thelarger. The matching will stop once any rule has been applied.

In the case of no le or ge command, the prefix length must match exactly thelength specified in the prefix list.

Command: no ip prefix-list name

14.2.1 ip prefix-list description

Command: ip prefix-list name description desc: Descriptions may be added to prefix lists. This command adds adescription to the prefix list.

Command: no ip prefix-list name description [desc]: Deletes the description from a prefix list. It is possible to use thecommand without the full description.

14.2.2 ip prefix-list sequential number control

Command: ip prefix-list sequence-number: With this command, the IP prefix list sequential number is displayed.This is the default behavior.

Command: no ip prefix-list sequence-number: With this command, the IP prefix list sequential number is notdisplayed.

14.2.3 Showing ip prefix-list

Command: show ip prefix-list: Display all IP prefix lists.

Command: show ip prefix-list name: Show IP prefix list can be used with a prefix list name.

Command: show ip prefix-list name seq num: Show IP prefix list can be used with a prefix list name and sequentialnumber.

Command: show ip prefix-list name a.b.c.d/m: If the command longer is used, all prefix lists with prefix lengths equal toor longer than the specified length will be displayed.If the command first match is used, the first prefix length match will bedisplayed.

Command: show ip prefix-list name a.b.c.d/m longer

Command: show ip prefix-list name a.b.c.d/m first-match

Command: show ip prefix-list summary

Command: show ip prefix-list summary name

Command: show ip prefix-list detail

Command: show ip prefix-list detail name

14.2.4 Clear counter of ip prefix-list

Command: clear ip prefix-list: Clears the counters of all IP prefix lists. Clear IP Prefix List can beused with a specified name and prefix.

Command: clear ip prefix-list name

Command: clear ip prefix-list name a.b.c.d/m

15 Route Map

Route maps provide a means to both filter and/or apply actions toroute, hence allowing policy to be applied to routes.

Route-maps are an ordered list of route-map entries. Each entry mayspecify up to four distincts sets of clauses:

‘Matching Policy’

This specifies the policy implied if the ‘Matching Conditions’ aremet or not met, and which actions of the route-map are to be taken, ifany. The two possibilities are:

- ‘permit’: If the entry matches, then carry out the ‘SetActions’. Then finish processing the route-map, permitting the route,unless an ‘Exit Action’ indicates otherwise.
- ‘deny’: If the entry matches, then finish processing the route-map anddeny the route (return ‘deny’).

The ‘Matching Policy’ is specified as part of the command whichdefines the ordered entry in the route-map. See below.

‘Matching Conditions’

A route-map entry may, optionally, specify one or more conditions whichmust be matched if the entry is to be considered further, as governedby the Match Policy. If a route-map entry does not explicitely specifyany matching conditions, then it always matches.

‘Set Actions’

A route-map entry may, optionally, specify one or more ‘SetActions’ to set or modify attributes of the route.

‘Call Action’

Call to another route-map, after any ‘Set Actions’ have beencarried out. If the route-map called returns ‘deny’ thenprocessing of the route-map finishes and the route is denied,regardless of the ‘Matching Policy’ or the ‘Exit Policy’. Ifthe called route-map returns ‘permit’, then ‘Matching Policy’and ‘Exit Policy’ govern further behaviour, as normal.

‘Exit Policy’

An entry may, optionally, specify an alternative ‘Exit Policy’ totake if the entry matched, rather than the normal policy of exiting theroute-map and permitting the route. The two possibilities are:

- ‘next’: Continue on with processing of the route-map entries.
- ‘goto N’: Jump ahead to the first route-map entry whose order inthe route-map is >= N. Jumping to a previous entry is not permitted.

The default action of a route-map, if no entries match, is to deny.I.e. a route-map essentially has as its last entry an empty ‘deny’entry, which matches all routes. To change this behaviour, one mustspecify an empty ‘permit’ entry as the last entry in the route-map.

To summarise the above:

	Match	No Match
Permit	action	cont
Deny	deny	cont

‘action’

- Apply set statements
- If call is present, call given route-map. If that returns a ‘deny’, finishprocessing and return ‘deny’.
- If ‘Exit Policy’ is next, goto next route-map entry
- If ‘Exit Policy’ is goto, goto first entry whose order in the listis >= the given order.
- Finish processing the route-map and permit the route.

‘deny’

- The route is denied by the route-map (return ‘deny’).

‘cont’

- goto next route-map entry

15.1 Route Map Command

Command: route-map route-map-name (permit|deny) order: Configure the order’th entry in route-map-name with‘Match Policy’ of either permit or deny.

15.2 Route Map Match Command

Route-map Command: match ip address access_list: Matches the specified access_list

Route-map Command: match ip next-hop ipv4_addr: Matches the specified ipv4_addr.

Route-map Command: match aspath as_path: Matches the specified as_path.

Route-map Command: match metric metric: Matches the specified metric.

Route-map Command: match local-preference metric: Matches the specified local-preference.

Route-map Command: match community community_list: Matches the specified community_list

15.3 Route Map Set Command

Route-map Command: set ip next-hop ipv4_address: Set the BGP nexthop address.

Route-map Command: set local-preference local_pref: Set the BGP local preference.

Route-map Command: set weight weight: Set the route’s weight.

Route-map Command: set metric metric: Set the BGP attribute MED.

Route-map Command: set as-path prepend as_path: Set the BGP AS path to prepend.

Route-map Command: set community community: Set the BGP community attribute.

Route-map Command: set ipv6 next-hop global ipv6_address: Set the BGP-4+ global IPv6 nexthop address.

Route-map Command: set ipv6 next-hop local ipv6_address: Set the BGP-4+ link local IPv6 nexthop address.

15.4 Route Map Call Command

Route-map Command: call name: Call route-map name. If it returns deny, deny the route andfinish processing the route-map.

15.5 Route Map Exit Action Command

Route-map Command: on-match next
Route-map Command: continue: Proceed on to the next entry in the route-map.

Route-map Command: on-match goto N
Route-map Command: continue N: Proceed processing the route-map at the first entry whose order is >= N

15.6 Route Map Examples

A simple example of a route-map:

route-map test permit 10
 match ip address 10
 set local-preference 200

This means that if a route matches ip access-list number 10 it’slocal-preference value is set to 200.

See BGP Configuration Examples for examples of more sophisticateduseage of route-maps, including of the ‘call’ action.

16 IPv6 Support

Quagga fully supports IPv6 routing. As described so far, Quagga supportsRIPng, OSPFv3, and BGP-4+. You can give IPv6 addresses to an interfaceand configure static IPv6 routing information. Quagga IPv6 also providesautomatic address configuration via a feature called addressauto configuration. To do it, the router must send router advertisementmessages to the all nodes that exist on the network.

16.1 Router Advertisement

Interface Command: no ipv6 nd suppress-ra: Send router advertisment messages.

Interface Command: ipv6 nd suppress-ra: Don’t send router advertisment messages.

Interface Command: ipv6 nd prefix ipv6prefix [valid-lifetime] [preferred-lifetime] [off-link] [no-autoconfig] [router-address]

Configuring the IPv6 prefix to include in router advertisements. Several prefixspecific optional parameters and flags may follow:

valid-lifetime - the length of time in seconds during what the prefix isvalid for the purpose of on-link determination. Value infinite representsinfinity (i.e. a value of all one bits (0xffffffff)).
Range: <0-4294967295> Default: 2592000
preferred-lifetime - the length of time in seconds during what addressesgenerated from the prefix remain preferred. Value infinite representsinfinity.
Range: <0-4294967295> Default: 604800
off-link - indicates that advertisement makes no statement about on-link oroff-link properties of the prefix.
Default: not set, i.e. this prefix can be used for on-link determination.
no-autoconfig - indicates to hosts on the local link that the specified prefixcannot be used for IPv6 autoconfiguration.
Default: not set, i.e. prefix can be used for autoconfiguration.
router-address - indicates to hosts on the local link that the specified prefix contains a complete IP address by setting R flag.
Default: not set, i.e. hosts do not assume a complete IP address is placed.

Interface Command: ipv6 nd ra-interval <1-1800>

Interface Command: no ipv6 nd ra-interval [<1-1800>]

The maximum time allowed between sending unsolicited multicast routeradvertisements from the interface, in seconds.

Default: 600

Interface Command: ipv6 nd ra-interval msec <70-1800000>

Interface Command: no ipv6 nd ra-interval [msec <70-1800000>]

The maximum time allowed between sending unsolicited multicast routeradvertisements from the interface, in milliseconds.

Default: 600000

Interface Command: ipv6 nd ra-lifetime <0-9000>

Interface Command: no ipv6 nd ra-lifetime [<0-9000>]

The value to be placed in the Router Lifetime field of router advertisementssent from the interface, in seconds. Indicates the usefulness of the routeras a default router on this interface. Setting the value to zero indicatesthat the router should not be considered a default router on this interface.Must be either zero or between value specified with ipv6 nd ra-interval(or default) and 9000 seconds.

Default: 1800

Interface Command: ipv6 nd reachable-time <1-3600000>

Interface Command: no ipv6 nd reachable-time [<1-3600000>]

The value to be placed in the Reachable Time field in the Router Advertisementmessages sent by the router, in milliseconds. The configured time enables therouter to detect unavailable neighbors. The value zero means unspecified (bythis router).

Default: 0

Interface Command: ipv6 nd managed-config-flag

Interface Command: no ipv6 nd managed-config-flag

Set/unset flag in IPv6 router advertisements which indicates to hosts that theyshould use managed (stateful) protocol for addresses autoconfiguration inaddition to any addresses autoconfigured using stateless addressautoconfiguration.

Default: not set

Interface Command: ipv6 nd other-config-flag

Interface Command: no ipv6 nd other-config-flag

Set/unset flag in IPv6 router advertisements which indicates to hosts thatthey should use administered (stateful) protocol to obtain autoconfigurationinformation other than addresses.

Default: not set

Interface Command: ipv6 nd home-agent-config-flag

Interface Command: no ipv6 nd home-agent-config-flag

Set/unset flag in IPv6 router advertisements which indicates to hosts thatthe router acts as a Home Agent and includes a Home Agent Option.

Default: not set

Interface Command: ipv6 nd home-agent-preference <0-65535>

Interface Command: no ipv6 nd home-agent-preference [<0-65535>]

The value to be placed in Home Agent Option, when Home Agent config flag is set, which indicates to hosts Home Agent preference. The default value of 0 standsfor the lowest preference possible.

Default: 0

Interface Command: ipv6 nd home-agent-lifetime <0-65520>

Interface Command: no ipv6 nd home-agent-lifetime [<0-65520>]

The value to be placed in Home Agent Option, when Home Agent config flag is set, which indicates to hosts Home Agent Lifetime. The default value of 0 means toplace the current Router Lifetime value.

Default: 0

Interface Command: ipv6 nd adv-interval-option

Interface Command: no ipv6 nd adv-interval-option

Include an Advertisement Interval option which indicates to hosts the maximum time, in milliseconds, between successive unsolicited Router Advertisements.

Default: not set

Interface Command: ipv6 nd router-preference (high|medium|low)

Interface Command: no ipv6 nd router-preference [(high|medium|low)]

Set default router preference in IPv6 router advertisements per RFC4191.

Default: medium

Interface Command: ipv6 nd mtu <1-65535>

Interface Command: no ipv6 nd mtu [<1-65535>]

Include an MTU (type 5) option in each RA packet to assist the attached hostsin proper interface configuration. The announced value is not verified to beconsistent with router interface MTU.

Default: don’t advertise any MTU option

interface eth0
 no ipv6 nd suppress-ra
 ipv6 nd prefix 2001:0DB8:5009::/64

For more information see RFC2462 (IPv6 Stateless Address Autoconfiguration), RFC4861 (Neighbor Discovery for IP Version 6 (IPv6)), RFC6275 (Mobility Support in IPv6)and RFC4191 (Default Router Preferences and More-Specific Routes).

17 Kernel Interface

There are several different methods for reading kernel routing tableinformation, updating kernel routing tables, and for looking upinterfaces.

‘ioctl’

The ‘ioctl’ method is a very traditional way for reading or writingkernel information. ‘ioctl’ can be used for looking up interfacesand for modifying interface addresses, flags, mtu settings and othertypes of information. Also, ‘ioctl’ can insert and delete kernelrouting table entries. It will soon be available on almost any platformwhich zebra supports, but it is a little bit ugly thus far, so if abetter method is supported by the kernel, zebra will use that.

‘sysctl’

‘sysctl’ can lookup kernel information using MIB (ManagementInformation Base) syntax. Normally, it only provides a way of gettinginformation from the kernel. So one would usually want to change kernelinformation using another method such as ‘ioctl’.

‘proc filesystem’

‘proc filesystem’ provides an easy way of getting kernelinformation.

‘routing socket’

‘netlink’

On recent Linux kernels (2.0.x and 2.2.x), there is a kernel/usercommunication support called netlink. It makes asynchronouscommunication between kernel and Quagga possible, similar to a routingsocket on BSD systems.

Before you use this feature, be sure to select (in kernel configuration) the kernel/netlink support option ’Kernel/User network link driver’ and ’Routing messages’.

Today, the /dev/route special device file is obsolete. Netlinkcommunication is done by reading/writing over netlink socket.

After the kernel configuration, please reconfigure and rebuild Quagga.You can use netlink as a dynamic routing update channel between Quaggaand the kernel.

18 SNMP Support

SNMP (Simple Network Managing Protocol) is a widely implementedfeature for collecting network information from router and/or host.Quagga itself does not support SNMP agent (server daemon) functionalitybut is able to connect to a SNMP agent using the SMUX protocol(RFC1227) or the AgentX protocol (RFC2741) and make therouting protocol MIBs available through it.

18.1 Getting and installing an SNMP agent

There are several SNMP agent which support SMUX or AgentX. We recommend to use the latestversion of net-snmp which was formerly known as ucd-snmp.It is free and open software and available at http://www.net-snmp.org/and as binary package for most Linux distributions.net-snmp has to be compiled with --with-mib-modules=agentx tobe able to accept connections from Quagga using AgentX protocol or with--with-mib-modules=smux to use SMUX protocol.

Nowadays, SMUX is a legacy protocol. The AgentX protocol should bepreferred for any new deployment. Both protocols have the same coverage.

18.2 AgentX configuration

To enable AgentX protocol support, Quagga must have been build with the--enable-snmp or --enable-snmp=agentx option. Both themaster SNMP agent (snmpd) and each of the Quagga daemons must beconfigured. In /etc/snmp/snmpd.conf, master agentxdirective should be added. In each of the Quagga daemons, agentxcommand will enable AgentX support.

/etc/snmp/snmpd.conf:
	#
	# example access restrictions setup
	#
	com2sec readonly default public
	group MyROGroup v1 readonly
	view all included .1 80
	access MyROGroup "" any noauth exact all none none
	#
	# enable master agent for AgentX subagents
	#
	master agentx

/etc/quagga/ospfd.conf:
	! ... the rest of ospfd.conf has been omitted for clarity ...
	!
	agentx
	!

Upon successful connection, you should get something like this in thelog of each Quagga daemons:

2012/05/25 11:39:08 ZEBRA: snmp[info]: NET-SNMP version 5.4.3 AgentX subagent connected

Then, you can use the following command to check everything works as expected:

# snmpwalk -c public -v1 localhost .1.3.6.1.2.1.14.1.1
OSPF-MIB::ospfRouterId.0 = IpAddress: 192.168.42.109
[...]

The AgentX protocol can be transported over a Unix socket or using TCPor UDP. It usually defaults to a Unix socket and depends on how NetSNMPwas built. If need to configure Quagga to use another transport, you canconfigure it through /etc/snmp/quagga.conf:

/etc/snmp/quagga.conf:
	[snmpd]
	# Use a remote master agent
	agentXSocket tcp:192.168.15.12:705

18.3 SMUX configuration

To enable SMUX protocol support, Quagga must have been build with the--enable-snmp=smux option.

A separate connection has then to be established between theSNMP agent (snmpd) and each of the Quagga daemons. This connectionseach use different OID numbers and passwords. Be aware that this OIDnumber is not the one that is used in queries by clients, it is solelyused for the intercommunication of the daemons.

In the following example the ospfd daemon will be connected to thesnmpd daemon using the password "quagga_ospfd". For testing it isrecommending to take exactly the below snmpd.conf as wrong accessrestrictions can be hard to debug.

/etc/snmp/snmpd.conf:
	#
	# example access restrictions setup
	#
	com2sec readonly default public
	group MyROGroup v1 readonly
	view all included .1 80
	access MyROGroup "" any noauth exact all none none
	#
	# the following line is relevant for Quagga
	#
	smuxpeer .1.3.6.1.4.1.3317.1.2.5 quagga_ospfd

/etc/quagga/ospf:
	! ... the rest of ospfd.conf has been omitted for clarity ...
	!
	smux peer .1.3.6.1.4.1.3317.1.2.5 quagga_ospfd
	!

After restarting snmpd and quagga, a successful connection can be verified inthe syslog and by querying the SNMP daemon:

snmpd[12300]: [smux_accept] accepted fd 12 from 127.0.0.1:36255 
snmpd[12300]: accepted smux peer: \
	oid GNOME-PRODUCT-ZEBRA-MIB::ospfd, quagga-0.96.5

# snmpwalk -c public -v1 localhost .1.3.6.1.2.1.14.1.1
OSPF-MIB::ospfRouterId.0 = IpAddress: 192.168.42.109

Be warned that the current version (5.1.1) of the Net-SNMP daemon writes a linefor every SNMP connect to the syslog which can lead to enormous log file sizes.If that is a problem you should consider to patch snmpd and comment out thetroublesome snmp_log() line in the functionnetsnmp_agent_check_packet() in agent/snmp_agent.c.

18.4 MIB and command reference

The following OID numbers are used for the interprocess communication of snmpd andthe Quagga daemons with SMUX only.

            (OIDs below .iso.org.dod.internet.private.enterprises)
zebra	.1.3.6.1.4.1.3317.1.2.1 .gnome.gnomeProducts.zebra.zserv
bgpd	.1.3.6.1.4.1.3317.1.2.2 .gnome.gnomeProducts.zebra.bgpd
ripd	.1.3.6.1.4.1.3317.1.2.3 .gnome.gnomeProducts.zebra.ripd
ospfd	.1.3.6.1.4.1.3317.1.2.5 .gnome.gnomeProducts.zebra.ospfd
ospf6d	.1.3.6.1.4.1.3317.1.2.6 .gnome.gnomeProducts.zebra.ospf6d

Sadly, SNMP has not been implemented in all daemons yet. The followingOID numbers are used for querying the SNMP daemon by a client:

zebra	.1.3.6.1.2.1.4.24   .iso.org.dot.internet.mgmt.mib-2.ip.ipForward
ospfd	.1.3.6.1.2.1.14	    .iso.org.dot.internet.mgmt.mib-2.ospf
bgpd	.1.3.6.1.2.1.15	    .iso.org.dot.internet.mgmt.mib-2.bgp 
ripd	.1.3.6.1.2.1.23	    .iso.org.dot.internet.mgmt.mib-2.rip2
ospf6d	.1.3.6.1.3.102	    .iso.org.dod.internet.experimental.ospfv3

The following syntax is understood by the Quagga daemons for configuring SNMP using SMUX:

Command: smux peer oid
Command: no smux peer oid

Command: smux peer oid password
Command: no smux peer oid password

Here is the syntax for using AgentX:

Command: agentx
Command: no agentx

18.5 Handling SNMP Traps

To handle snmp traps make sure your snmp setup of quagga workscorrectly as described in the quagga documentation in See SNMP Support.

The BGP4 mib will send traps on peer up/down events. These should bevisible in your snmp logs with a message similar to:

‘snmpd[13733]: Got trap from peer on fd 14’

To react on these traps they should be handled by a trapsink. Configureyour trapsink by adding the following lines to /etc/snmpd/snmpd.conf:

  # send traps to the snmptrapd on localhost
  trapsink localhost

This will send all traps to an snmptrapd running on localhost. You canof course also use a dedicated management station to catch traps.Configure the snmptrapd daemon by adding the following line to/etc/snmpd/snmptrapd.conf:

  traphandle .1.3.6.1.4.1.3317.1.2.2 /etc/snmp/snmptrap_handle.sh

This will use the bash script /etc/snmp/snmptrap_handle.sh to handlethe BGP4 traps. To add traps for other protocol daemons, lookup theirappropriate OID from their mib. (For additional information about whichtraps are supported by your mib, lookup the mib onhttp://www.oidview.com/mibs/detail.html).

Make sure snmptrapd is started.

The snmptrap_handle.sh script I personally use for handling BGP4 trapsis below. You can of course do all sorts of things when handling traps,like sound a siren, have your display flash, etc., be creative ;).

  #!/bin/bash

  # routers name
  ROUTER=`hostname -s`

  #email address use to sent out notification
  EMAILADDR="john@doe.com"
  #email address used (allongside above) where warnings should be sent
  EMAILADDR_WARN="sms-john@doe.com"

  # type of notification
  TYPE="Notice"

  # local snmp community for getting AS belonging to peer
  COMMUNITY="<community>"

  # if a peer address is in $WARN_PEERS a warning should be sent
  WARN_PEERS="192.0.2.1"


  # get stdin
  INPUT=`cat -`

  # get some vars from stdin
  uptime=`echo $INPUT | cut -d' ' -f5`
  peer=`echo $INPUT | cut -d' ' -f8 | \
	sed -e 's/SNMPv2-SMI::mib-2.15.3.1.14.//g'`
  peerstate=`echo $INPUT | cut -d' ' -f13`
  errorcode=`echo $INPUT | cut -d' ' -f9 | sed -e 's/\"//g'`
  suberrorcode=`echo $INPUT | cut -d' ' -f10 | sed -e 's/\"//g'`
  remoteas=`snmpget -v2c -c $COMMUNITY \
		localhost SNMPv2-SMI::mib-2.15.3.1.9.$peer \
		| cut -d' ' -f4`

  WHOISINFO=`whois -h whois.ripe.net " -r AS$remoteas" | \
		egrep '(as-name|descr)'`
  asname=`echo "$WHOISINFO" | grep "^as-name:" | \
		sed -e 's/^as-name://g' -e 's/  //g' -e 's/^ //g' | uniq`
  asdescr=`echo "$WHOISINFO" | grep "^descr:" | \
		sed -e 's/^descr://g' -e 's/  //g' -e 's/^ //g' | uniq`

  # if peer address is in $WARN_PEER, the email should also
  # be sent to $EMAILADDR_WARN
  for ip in $WARN_PEERS; do
    if [ "x$ip" == "x$peer" ]; then
      EMAILADDR="$EMAILADDR,$EMAILADDR_WARN"
      TYPE="WARNING"
      break
    fi
  done
  

  # convert peer state
  case "$peerstate" in
    1) peerstate="Idle" ;;
    2) peerstate="Connect" ;;
    3) peerstate="Active" ;;
    4) peerstate="Opensent" ;;
    5) peerstate="Openconfirm" ;;
    6) peerstate="Established" ;;
    *) peerstate="Unknown" ;;
  esac

  # get textual messages for errors
  case "$errorcode" in
    00)
      error="No error"
      suberror=""
      ;;
    01)
      error="Message Header Error"
      case "$suberrorcode" in
        01) suberror="Connection Not Synchronized" ;;
        02) suberror="Bad Message Length" ;;
        03) suberror="Bad Message Type" ;;
        *) suberror="Unknown" ;;
      esac
      ;;
    02)    
      error="OPEN Message Error"
      case "$suberrorcode" in
        01) suberror="Unsupported Version Number" ;;
        02) suberror="Bad Peer AS" ;;
        03) suberror="Bad BGP Identifier" ;;
        04) suberror="Unsupported Optional Parameter" ;;
        05) suberror="Authentication Failure" ;;
        06) suberror="Unacceptable Hold Time" ;;
        *) suberror="Unknown" ;;
      esac
      ;;
    03)
      error="UPDATE Message Error"
      case "$suberrorcode" in
        01) suberror="Malformed Attribute List" ;;
        02) suberror="Unrecognized Well-known Attribute" ;;
        03) suberror="Missing Well-known Attribute" ;;
        04) suberror="Attribute Flags Error" ;;
        05) suberror="Attribute Length Error" ;;
        06) suberror="Invalid ORIGIN Attribute" ;;
        07) suberror="AS Routing Loop" ;;
        08) suberror="Invalid NEXT_HOP Attribute" ;;
        09) suberror="Optional Attribute Error" ;;
        10) suberror="Invalid Network Field" ;;
        11) suberror="Malformed AS_PATH" ;;
        *) suberror="Unknown" ;;
      esac
      ;;
    04)
      error="Hold Timer Expired"
      suberror=""
      ;;
    05)
      error="Finite State Machine Error"
      suberror=""
      ;;
    06)
      error="Cease"
      case "$suberrorcode" in
        01) suberror="Maximum Number of Prefixes Reached" ;;
        02) suberror="Administratively Shutdown" ;;
        03) suberror="Peer Unconfigured" ;;
        04) suberror="Administratively Reset" ;;
        05) suberror="Connection Rejected" ;;
        06) suberror="Other Configuration Change" ;;
        07) suberror="Connection collision resolution" ;;
        08) suberror="Out of Resource" ;;
        09) suberror="MAX" ;;
        *) suberror="Unknown" ;;
      esac
      ;;
    *)
      error="Unknown"
      suberror=""
      ;;
  esac

  # create textual message from errorcodes
  if [ "x$suberror" == "x" ]; then
    NOTIFY="$errorcode ($error)"
  else
    NOTIFY="$errorcode/$suberrorcode ($error/$suberror)"
  fi
 

  # form a decent subject
  SUBJECT="$TYPE: $ROUTER [bgp] $peer is $peerstate: $NOTIFY"
  # create the email body
  MAIL=`cat << EOF
  BGP notification on router $ROUTER.
  
  Peer: $peer
  AS: $remoteas
  New state: $peerstate
  Notification: $NOTIFY

  Info:
  $asname
  $asdescr
 
  Snmpd uptime: $uptime
  EOF`

  # mail the notification
  echo "$MAIL" | mail -s "$SUBJECT" $EMAILADDR

Appendix A Zebra Protocol

A.1 Overview of the Zebra Protocol

Zebra Protocol is used by protocol daemons to communicate with thezebra daemon.

Each protocol daemon may request and send information to and from thezebra daemon such as interface states, routing state,nexthop-validation, and so on. Protocol daemons may also install routeswith zebra. The zebra daemon manages which route is installed into theforwarding table with the kernel.

Zebra Protocol is a streaming protocol, with a common header. Twoversions of the header are in use. Version 0 is implicitely versioned.Version 1 has an explicit version field. Version 0 can be distinguishedfrom all other versions by examining the 3rd byte of the header, whichcontains a marker value for all versions bar version 0. The marker bytecorresponds to the command field in version 0, and the marker value isa reserved command in version 0.

We do not anticipate there will be further versions of the header forthe foreseeable future, as the command field in version 1 is wideenough to allow for future extensions to done compatibly throughseperate commands.

Version 0 is used by all versions of GNU Zebra as of this writing, andversions of Quagga up to and including Quagga 0.98. Version 1 will beused as of Quagga 1.0.

A.2 Zebra Protocol Definition

A.2.1 Zebra Protocol Header (version 0)

0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+---------------+
|           Length (2)          |   Command (1) |
+-------------------------------+---------------+

A.2.2 Zebra Protocol Common Header (version 1)

0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+---------------+-------------+
|           Length (2)          |   Marker (1)  | Version (1) |
+-------------------------------+---------------+-------------+
|          Command (2)          |
+-------------------------------+

A.2.3 Zebra Protocol Header Field Definitions

‘Length’: Total packet length including this header. The minimum length is 3bytes for version 0 messages and 6 bytes for version 1 messages.
‘Marker’: Static marker with a value of 255 always. This is to allow version 0Zserv headers (which do not include version explicitely) to bedistinguished from versioned headers. Not present in version 0messages.
‘Version’: Version number of the Zserv message. Clients should not continueprocessing messages past the version field for versions they do notrecognise. Not present in version 0 messages.
‘Command’: The Zebra Protocol command.

A.2.4 Zebra Protocol Commands

Command	Value
ZEBRA_INTERFACE_ADD	1
ZEBRA_INTERFACE_DELETE	2
ZEBRA_INTERFACE_ADDRESS_ADD	3
ZEBRA_INTERFACE_ADDRESS_DELETE	4
ZEBRA_INTERFACE_UP	5
ZEBRA_INTERFACE_DOWN	6
ZEBRA_IPV4_ROUTE_ADD	7
ZEBRA_IPV4_ROUTE_DELETE	8
ZEBRA_IPV6_ROUTE_ADD	9
ZEBRA_IPV6_ROUTE_DELETE	10
ZEBRA_REDISTRIBUTE_ADD	11
ZEBRA_REDISTRIBUTE_DELETE	12
ZEBRA_REDISTRIBUTE_DEFAULT_ADD	13
ZEBRA_REDISTRIBUTE_DEFAULT_DELETE	14
ZEBRA_IPV4_NEXTHOP_LOOKUP	15
ZEBRA_IPV6_NEXTHOP_LOOKUP	16

Appendix B Packet Binary Dump Format

Quagga can dump routing protocol packet into file with a binary format(see Dump BGP packets and table).

It seems to be better that we share the MRT’s header format forbackward compatibility with MRT’s dump logs. We should also define thebinary format excluding the header, because we must support both IPv4 and v6 addresses as socket addresses and / or routing entries.

In the last meeting, we discussed to have a version field in theheader. But Masaki told us that we can define new ‘type’ value ratherthan having a ‘version’ field, and it seems to be better because wedon’t need to change header format.

Here is the common header format. This is same as that of MRT.

0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                              Time                             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|             Type              |            Subtype            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                             Length                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

If ‘type’ is PROTOCOL_BGP4MP_ET, the common header format willcontain an additional microsecond field (RFC6396 2011).

0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                              Time                             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|             Type              |            Subtype            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                             Length                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                          Microsecond                          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

If ‘type’ is PROTOCOL_BGP4MP, ‘subtype’ is BGP4MP_STATE_CHANGE, andAddress Family == IP (version 4)

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Source AS number       |     Destination AS number     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Interface Index        |      Address Family           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address                    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|            Old State          |           New State           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Where State is the value defined in RFC1771.

If ‘type’ is PROTOCOL_BGP4MP, ‘subtype’ is BGP4MP_STATE_CHANGE,and Address Family == IP version 6

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Source AS number       |     Destination AS number     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Interface Index        |      Address Family           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address (Cont'd)             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address (Cont'd)             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address (Cont'd)             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address                    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address (Cont'd)           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address (Cont'd)           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address (Cont'd)           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|            Old State          |           New State           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

If ‘type’ is PROTOCOL_BGP4MP, ‘subtype’ is BGP4MP_MESSAGE,and Address Family == IP (version 4)

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Source AS number       |     Destination AS number     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Interface Index        |      Address Family           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address                    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                       BGP Message Packet                      |
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Where BGP Message Packet is the whole contents of theBGP4 message including header portion.

If ‘type’ is PROTOCOL_BGP4MP, ‘subtype’ is BGP4MP_MESSAGE,and Address Family == IP version 6

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Source AS number       |     Destination AS number     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Interface Index        |      Address Family           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address (Cont'd)             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address (Cont'd)             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Source IP address (Cont'd)             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address                    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address (Cont'd)           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address (Cont'd)           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Destination IP address (Cont'd)           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                       BGP Message Packet                      |
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

If ‘type’ is PROTOCOL_BGP4MP, ‘subtype’ is BGP4MP_ENTRY,and Address Family == IP (version 4)

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|            View #             |            Status             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Time Last Change                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Address Family          |    SAFI       | Next-Hop-Len  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Next Hop Address                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix Length |             Address Prefix [variable]         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Attribute Length        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      BGP Attribute [variable length]    			|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

If ‘type’ is PROTOCOL_BGP4MP, ‘subtype’ is BGP4MP_ENTRY,and Address Family == IP version 6

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|            View #             |            Status             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Time Last Change                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Address Family          |    SAFI       | Next-Hop-Len  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Next Hop Address                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Next Hop Address (Cont'd)              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Next Hop Address (Cont'd)              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Next Hop Address (Cont'd)              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix Length |             Address Prefix [variable]         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Address Prefix (cont'd) [variable]        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Attribute Length        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      BGP Attribute [variable length]    			    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

BGP4 Attribute must not contain MP_UNREACH_NLRI.If BGP Attribute has MP_REACH_NLRI field, it must haszero length NLRI, e.g., MP_REACH_NLRI has only AddressFamily, SAFI and next-hop values.

If ‘type’ is PROTOCOL_BGP4MP and ‘subtype’ is BGP4MP_SNAPSHOT,

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           View #              |       File Name [variable]    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The file specified in "File Name" contains all routing entries, which are in the format of “subtype == BGP4MP_ENTRY”.

Constants:
  /* type value */
  #define MSG_PROTOCOL_BGP4MP    16
  #define MSG_PROTOCOL_BGP4MP_ET 17
  /* subtype value */
  #define BGP4MP_STATE_CHANGE 0
  #define BGP4MP_MESSAGE 1
  #define BGP4MP_ENTRY 2
  #define BGP4MP_SNAPSHOT 3

Command Index

Jump to:	A B C D E F H I L M N O P R S T U V W

	Index Entry	Section

A
	`access-class access-list`:	Basic Config Commands
	`access-list name deny ipv4-network`:	IP Access List
	`access-list name permit ipv4-network`:	IP Access List
	`admin-grp bandwidth`:	Link Parameters Commands
	`agentx`:	MIB and command reference
	`aggregate-address A.B.C.D/M`:	Route Aggregation
	`aggregate-address A.B.C.D/M as-set`:	Route Aggregation
	`aggregate-address A.B.C.D/M summary-only`:	Route Aggregation
	`area <0-4294967295> authentication`:	OSPF area
	`area <0-4294967295> authentication message-digest`:	OSPF area
	`area <0-4294967295> export-list NAME`:	OSPF area
	`area <0-4294967295> filter-list prefix NAME in`:	OSPF area
	`area <0-4294967295> filter-list prefix NAME out`:	OSPF area
	`area <0-4294967295> import-list NAME`:	OSPF area
	`area <0-4294967295> range a.b.c.d/m`:	OSPF area
	`area <0-4294967295> shortcut`:	OSPF area
	`area <0-4294967295> stub`:	OSPF area
	`area <0-4294967295> stub no-summary`:	OSPF area
	`area <0-4294967295> virtual-link a.b.c.d`:	OSPF area
	`area a.b.c.d authentication`:	OSPF area
	`area a.b.c.d authentication message-digest`:	OSPF area
	`area a.b.c.d default-cost <0-16777215>`:	OSPF area
	`area a.b.c.d export-list NAME`:	OSPF area
	`area a.b.c.d filter-list prefix NAME in`:	OSPF area
	`area a.b.c.d filter-list prefix NAME out`:	OSPF area
	`area a.b.c.d import-list NAME`:	OSPF area
	`area a.b.c.d range a.b.c.d/m`:	OSPF area
	`area a.b.c.d range IPV4_PREFIX not-advertise`:	OSPF area
	`area a.b.c.d range IPV4_PREFIX substitute IPV4_PREFIX`:	OSPF area
	`area a.b.c.d shortcut`:	OSPF area
	`area a.b.c.d stub`:	OSPF area
	`area a.b.c.d stub no-summary`:	OSPF area
	`area a.b.c.d virtual-link a.b.c.d`:	OSPF area
	`area-password [clear \| md5] <password>`:	ISIS router
	`auto-cost reference-bandwidth <1-4294967>`:	OSPF router
	`auto-cost reference-bandwidth cost`:	OSPF6 router
	`ava-bw bandwidth`:	Link Parameters Commands

B
	`bandwidth <1-10000000>`:	Standard Commands
	`banner motd default`:	Basic Config Commands
	`bgp always-compare-med`:	BGP MED
	`bgp bestpath as-path confed`:	BGP decision process
	`bgp bestpath as-path multipath-relax`:	BGP decision process
	`bgp bestpath compare-routerid`:	BGP decision process
	`bgp cluster-id a.b.c.d`:	Route Reflector
	`bgp config-type cisco`:	Multiple instance
	`bgp config-type zebra`:	Multiple instance
	`bgp dampening <1-45> <1-20000> <1-20000> <1-255>`:	BGP route flap dampening
	`bgp deterministic-med`:	BGP MED
	`bgp multiple-instance`:	Multiple instance
	`bgp route-reflector allow-outbound-policy`:	Peer filtering
	`bgp router-id A.B.C.D`:	BGP router

C
	`call name`:	Route Map Call Command
	`call WORD`:	Commands for configuring a Route Server
	`capability opaque`:	Opaque LSA
	`clear ip bgp peer`:	More Show IP BGP
	`clear ip bgp peer soft in`:	More Show IP BGP
	`clear ip prefix-list`:	Clear counter of ip prefix-list
	`clear ip prefix-list name`:	Clear counter of ip prefix-list
	`clear ip prefix-list name a.b.c.d/m`:	Clear counter of ip prefix-list
	`clear zebra fpm stats`:	zebra Terminal Mode Commands
	`configure terminal`:	Terminal Mode Commands
	`continue`:	Route Map Exit Action Command
	`continue N`:	Route Map Exit Action Command

D
	`debug event`:	More Show IP BGP
	`debug isis adj-packets`:	Debugging ISIS
	`debug isis checksum-errors`:	Debugging ISIS
	`debug isis events`:	Debugging ISIS
	`debug isis local-updates`:	Debugging ISIS
	`debug isis packet-dump`:	Debugging ISIS
	`debug isis protocol-errors`:	Debugging ISIS
	`debug isis route-events`:	Debugging ISIS
	`debug isis snp-packets`:	Debugging ISIS
	`debug isis spf-events`:	Debugging ISIS
	`debug isis spf-statistics`:	Debugging ISIS
	`debug isis spf-triggers`:	Debugging ISIS
	`debug isis update-packets`:	Debugging ISIS
	`debug keepalive`:	More Show IP BGP
	`debug ospf event`:	Debugging OSPF
	`debug ospf ism`:	Debugging OSPF
	`debug ospf ism (status\|events\|timers)`:	Debugging OSPF
	`debug ospf lsa`:	Debugging OSPF
	`debug ospf lsa (generate\|flooding\|refresh)`:	Debugging OSPF
	`debug ospf nsm`:	Debugging OSPF
	`debug ospf nsm (status\|events\|timers)`:	Debugging OSPF
	`debug ospf nssa`:	Debugging OSPF
	`debug ospf packet (hello\|dd\|ls-request\|ls-update\|ls-ack\|all) (send\|recv) [detail]`:	Debugging OSPF
	`debug ospf te`:	Debugging OSPF
	`debug ospf zebra`:	Debugging OSPF
	`debug ospf zebra (interface\|redistribute)`:	Debugging OSPF
	`debug rip events`:	RIP Debug Commands
	`debug rip packet`:	RIP Debug Commands
	`debug rip zebra`:	RIP Debug Commands
	`debug ripng events`:	ripngd Terminal Mode Commands
	`debug ripng packet`:	ripngd Terminal Mode Commands
	`debug ripng zebra`:	ripngd Terminal Mode Commands
	`debug update`:	More Show IP BGP
	`default-information originate`:	How to Announce RIP route
	`default-information originate`:	Redistribute routes to OSPF
	`default-information originate always`:	Redistribute routes to OSPF
	`default-information originate always metric <0-16777214>`:	Redistribute routes to OSPF
	`default-information originate always metric <0-16777214> metric-type (1\|2)`:	Redistribute routes to OSPF
	`default-information originate always metric <0-16777214> metric-type (1\|2) route-map word`:	Redistribute routes to OSPF
	`default-information originate metric <0-16777214>`:	Redistribute routes to OSPF
	`default-information originate metric <0-16777214> metric-type (1\|2)`:	Redistribute routes to OSPF
	`default-information originate metric <0-16777214> metric-type (1\|2) route-map word`:	Redistribute routes to OSPF
	`default-metric <0-16777214>`:	Redistribute routes to OSPF
	`default-metric <1-16>`:	RIP Metric Manipulation
	`delay <0-16777215> [min <0-16777215> \| max <0-16777215>]`:	Link Parameters Commands
	`delay-variation <0-16777215>`:	Link Parameters Commands
	`description description ...`:	Standard Commands
	`distance <1-255>`:	RIP distance
	`distance <1-255>`:	Redistribute routes to OSPF
	`distance <1-255> A.B.C.D/M`:	RIP distance
	`distance <1-255> A.B.C.D/M`:	BGP distance
	`distance <1-255> A.B.C.D/M access-list`:	RIP distance
	`distance <1-255> A.B.C.D/M word`:	BGP distance
	`distance bgp <1-255> <1-255> <1-255>`:	BGP distance
	`distance ospf (intra-area\|inter-area\|external) <1-255>`:	Redistribute routes to OSPF
	`distribute-list access_list (in\|out) ifname`:	ripngd Filtering Commands
	`distribute-list access_list direct ifname`:	Filtering RIP Routes
	`distribute-list NAME out (kernel\|connected\|static\|rip\|ospf`:	Redistribute routes to OSPF
	`distribute-list prefix prefix_list (in\|out) ifname`:	Filtering RIP Routes
	`domain-password [clear \| md5] <password>`:	ISIS router
	`dump bgp all path [interval]`:	Dump BGP packets and table
	`dump bgp all-et path [interval]`:	Dump BGP packets and table
	`dump bgp routes-mrt path`:	Dump BGP packets and table
	`dump bgp routes-mrt path interval`:	Dump BGP packets and table
	`dump bgp updates path [interval]`:	Dump BGP packets and table
	`dump bgp updates-et path [interval]`:	Dump BGP packets and table

E
	`enable`:	Link Parameters Commands
	`enable password password`:	Basic Config Commands
	`exec-timeout minute`:	Basic Config Commands
	`exec-timeout minute second`:	Basic Config Commands

F
	`flush_timer time`:	ripngd Configuration

H
	`hostname dynamic`:	ISIS router
	`hostname hostname`:	Basic Config Commands

I
	`interface ifname`:	Standard Commands
	`interface ifname area area`:	OSPF6 router
	`ip address address/prefix`:	Standard Commands
	`ip address address/prefix secondary`:	Standard Commands
	`ip as-path access-list word {permit\|deny} line`:	AS Path Access List
	`ip community-list <1-99> {permit\|deny} community`:	Numbered BGP Community Lists
	`ip community-list <100-199> {permit\|deny} community`:	Numbered BGP Community Lists
	`ip community-list expanded name {permit\|deny} line`:	BGP Community Lists
	`ip community-list name {permit\|deny} community`:	Numbered BGP Community Lists
	`ip community-list standard name {permit\|deny} community`:	BGP Community Lists
	`ip extcommunity-list expanded name {permit\|deny} line`:	BGP Extended Community Lists
	`ip extcommunity-list standard name {permit\|deny} extcommunity`:	BGP Extended Community Lists
	`ip mroute prefix nexthop [distance]`:	Multicast RIB Commands
	`ip multicast rpf-lookup-mode mode`:	Multicast RIB Commands
	`ip ospf area AREA [ADDR]`:	OSPF interface
	`ip ospf authentication message-digest`:	OSPF interface
	`ip ospf authentication-key AUTH_KEY`:	OSPF interface
	`ip ospf cost <1-65535>`:	OSPF interface
	`ip ospf dead-interval <1-65535>`:	OSPF interface
	`ip ospf dead-interval minimal hello-multiplier <2-20>`:	OSPF interface
	`ip ospf hello-interval <1-65535>`:	OSPF interface
	`ip ospf message-digest-key KEYID md5 KEY`:	OSPF interface
	`ip ospf network (broadcast\|non-broadcast\|point-to-multipoint\|point-to-point)`:	OSPF interface
	`ip ospf priority <0-255>`:	OSPF interface
	`ip ospf retransmit-interval <1-65535>`:	OSPF interface
	`ip ospf transmit-delay`:	OSPF interface
	`ip prefix-list name (permit\|deny) prefix [le len] [ge len]`:	IP Prefix List
	`ip prefix-list name description desc`:	ip prefix-list description
	`ip prefix-list name seq number (permit\|deny) prefix [le len] [ge len]`:	IP Prefix List
	`ip prefix-list sequence-number`:	ip prefix-list sequential number control
	`ip protocol protocol route-map routemap`:	zebra Route Filtering
	`ip rip authentication key-chain key-chain`:	RIP Authentication
	`ip rip authentication mode md5`:	RIP Authentication
	`ip rip authentication mode text`:	RIP Authentication
	`ip rip authentication string string`:	RIP Authentication
	`ip rip receive version version`:	RIP Version Control
	`ip rip send version version`:	RIP Version Control
	`ip route network gateway`:	Static Route Commands
	`ip route network gateway distance`:	Static Route Commands
	`ip route network netmask gateway`:	Static Route Commands
	`ip router isis WORD`:	ISIS interface
	`ip split-horizon`:	RIP Configuration
	`ipv6 address address/prefix`:	Standard Commands
	`ipv6 nd adv-interval-option`:	Router Advertisement
	`ipv6 nd home-agent-config-flag`:	Router Advertisement
	`ipv6 nd home-agent-lifetime <0-65520>`:	Router Advertisement
	`ipv6 nd home-agent-preference <0-65535>`:	Router Advertisement
	`ipv6 nd managed-config-flag`:	Router Advertisement
	`ipv6 nd mtu <1-65535>`:	Router Advertisement
	`ipv6 nd other-config-flag`:	Router Advertisement
	`ipv6 nd prefix ipv6prefix [valid-lifetime] [preferred-lifetime] [off-link] [no-autoconfig] [router-address]`:	Router Advertisement
	`ipv6 nd ra-interval <1-1800>`:	Router Advertisement
	`ipv6 nd ra-interval msec <70-1800000>`:	Router Advertisement
	`ipv6 nd ra-lifetime <0-9000>`:	Router Advertisement
	`ipv6 nd reachable-time <1-3600000>`:	Router Advertisement
	`ipv6 nd router-preference (high\|medium\|low)`:	Router Advertisement
	`ipv6 nd suppress-ra`:	Router Advertisement
	`ipv6 ospf6 cost COST`:	OSPF6 interface
	`ipv6 ospf6 dead-interval DEADINTERVAL`:	OSPF6 interface
	`ipv6 ospf6 hello-interval HELLOINTERVAL`:	OSPF6 interface
	`ipv6 ospf6 network (broadcast\|point-to-point)`:	OSPF6 interface
	`ipv6 ospf6 priority PRIORITY`:	OSPF6 interface
	`ipv6 ospf6 retransmit-interval RETRANSMITINTERVAL`:	OSPF6 interface
	`ipv6 ospf6 transmit-delay TRANSMITDELAY`:	OSPF6 interface
	`ipv6 route network gateway`:	Static Route Commands
	`ipv6 route network gateway distance`:	Static Route Commands
	`is-type [level-1 \| level-1-2 \| level-2-only]`:	ISIS region
	`isis circuit-type [level-1 \| level-1-2 \| level-2]`:	ISIS interface
	`isis csnp-interval <1-600>`:	ISIS interface
	`isis csnp-interval <1-600> [level-1 \| level-2]`:	ISIS interface
	`isis hello padding`:	ISIS interface
	`isis hello-interval <1-600>`:	ISIS interface
	`isis hello-interval <1-600> [level-1 \| level-2]`:	ISIS interface
	`isis hello-multiplier <2-100>`:	ISIS interface
	`isis hello-multiplier <2-100> [level-1 \| level-2]`:	ISIS interface
	`isis metric [<0-255> \| <0-16777215>]`:	ISIS interface
	`isis metric [<0-255> \| <0-16777215>] [level-1 \| level-2]`:	ISIS interface
	`isis network point-to-point`:	ISIS interface
	`isis passive`:	ISIS interface
	`isis password [clear \| md5] <password>`:	ISIS interface
	`isis priority <0-127>`:	ISIS interface
	`isis priority <0-127> [level-1 \| level-2]`:	ISIS interface
	`isis psnp-interval <1-120>`:	ISIS interface
	`isis psnp-interval <1-120> [level-1 \| level-2]`:	ISIS interface

L
	`line vty`:	Basic Config Commands
	`link-detect`:	Standard Commands
	`link-params`:	Link Parameters Commands
	`list`:	Terminal Mode Commands
	`log commands`:	Basic Config Commands
	`log facility facility`:	Basic Config Commands
	`log file filename`:	Basic Config Commands
	`log file filename level`:	Basic Config Commands
	`log monitor`:	Basic Config Commands
	`log monitor level`:	Basic Config Commands
	`log record-priority`:	Basic Config Commands
	`log stdout`:	Basic Config Commands
	`log stdout level`:	Basic Config Commands
	`log syslog`:	Basic Config Commands
	`log syslog level`:	Basic Config Commands
	`log timestamp precision <0-6>`:	Basic Config Commands
	`log trap level`:	Basic Config Commands
	`log-adjacency-changes`:	ISIS router
	`log-adjacency-changes [detail]`:	OSPF router
	`logmsg level message`:	Terminal Mode Commands
	`lsp-gen-interval <1-120>`:	ISIS Timer
	`lsp-gen-interval [level-1 \| level-2] <1-120>`:	ISIS Timer
	`lsp-refresh-interval <1-65235>`:	ISIS Timer
	`lsp-refresh-interval <1-65235>`:	ISIS Timer
	`lsp-refresh-interval [level-1 \| level-2] <1-65235>`:	ISIS Timer
	`lsp-refresh-interval [level-1 \| level-2] <1-65235>`:	ISIS Timer

M
	`match as-path word`:	Using AS Path in Route Map
	`match aspath as_path`:	Route Map Match Command
	`match community community_list`:	Route Map Match Command
	`match community word`:	BGP Community in Route Map
	`match community word exact-match`:	BGP Community in Route Map
	`match extcommunity word`:	BGP Extended Communities in Route Map
	`match interface word`:	RIP route-map
	`match ip address access_list`:	Route Map Match Command
	`match ip address prefix-list word`:	RIP route-map
	`match ip address word`:	RIP route-map
	`match ip next-hop ipv4_addr`:	Route Map Match Command
	`match ip next-hop prefix-list word`:	RIP route-map
	`match ip next-hop word`:	RIP route-map
	`match local-preference metric`:	Route Map Match Command
	`match metric <0-4294967295>`:	RIP route-map
	`match metric metric`:	Route Map Match Command
	`match peer {A.B.C.D\|X:X::X:X}`:	Commands for configuring a Route Server
	`max-bw bandwidth`:	Link Parameters Commands
	`max-lsp-lifetime <360-65535>`:	ISIS Timer
	`max-lsp-lifetime [level-1 \| level-2] <360-65535>`:	ISIS Timer
	`max-metric router-lsa administrative`:	OSPF router
	`max-metric router-lsa [on-startup\|on-shutdown] <5-86400>`:	OSPF router
	`max-rsv-bw bandwidth`:	Link Parameters Commands
	`metric <0-4294967295>`:	Link Parameters Commands
	`metric-style [narrow \| transition \| wide]`:	ISIS router
	`mpls-te inter-as area <area-id>\|as`:	OSPF Traffic Engineering
	`mpls-te on`:	OSPF Traffic Engineering
	`mpls-te on`:	ISIS Traffic Engineering
	`mpls-te router-address <A.B.C.D>`:	OSPF Traffic Engineering
	`mpls-te router-address <A.B.C.D>`:	ISIS Traffic Engineering
	`multicast`:	Standard Commands

N
	`neigbor {A.B.C.D\|X.X::X.X\|peer-group} route-map WORD {import\|export}`:	Commands for configuring a Route Server
	`neighbor <A.B.C.D> as <0-65535>`:	Link Parameters Commands
	`neighbor a.b.c.d`:	RIP Configuration
	`neighbor A.B.C.D route-server-client`:	Commands for configuring a Route Server
	`neighbor peer default-originate`:	BGP Peer commands
	`neighbor peer description ...`:	BGP Peer commands
	`neighbor peer distribute-list name [in\|out]`:	Peer filtering
	`neighbor peer dont-capability-negotiate`:	Capability Negotiation
	`neighbor peer ebgp-multihop`:	BGP Peer commands
	`neighbor peer filter-list name [in\|out]`:	Peer filtering
	`neighbor peer interface ifname`:	BGP Peer commands
	`neighbor peer local-as as-number`:	BGP Peer commands
	`neighbor peer local-as as-number no-prepend`:	BGP Peer commands
	`neighbor peer local-as as-number no-prepend replace-as`:	BGP Peer commands
	`neighbor peer maximum-prefix number`:	BGP Peer commands
	`neighbor peer next-hop-self [all]`:	BGP Peer commands
	`neighbor peer override-capability`:	Capability Negotiation
	`neighbor peer peer-group word`:	BGP Peer Group
	`neighbor peer port port`:	BGP Peer commands
	`neighbor peer port port`:	BGP Peer commands
	`neighbor peer prefix-list name [in\|out]`:	Peer filtering
	`neighbor peer remote-as asn`:	Defining Peer
	`neighbor peer route-map name [in\|out]`:	Peer filtering
	`neighbor peer route-reflector-client`:	Route Reflector
	`neighbor peer send-community`:	BGP Peer commands
	`neighbor peer send-community`:	BGP Peer commands
	`neighbor peer shutdown`:	BGP Peer commands
	`neighbor peer strict-capability-match`:	Capability Negotiation
	`neighbor peer ttl-security hops number`:	BGP Peer commands
	`neighbor peer update-source <ifname\|address>`:	BGP Peer commands
	`neighbor peer version version`:	BGP Peer commands
	`neighbor peer weight weight`:	BGP Peer commands
	`neighbor peer-group route-server-client`:	Commands for configuring a Route Server
	`neighbor word peer-group`:	BGP Peer Group
	`neighbor X:X::X:X route-server-client`:	Commands for configuring a Route Server
	`net XX.XXXX. ... .XXX.XX`:	ISIS router
	`network A.B.C.D/M`:	BGP route
	`network a.b.c.d/m area <0-4294967295>`:	OSPF router
	`network a.b.c.d/m area a.b.c.d`:	OSPF router
	`network ifname`:	RIP Configuration
	`network ifname`:	ripngd Configuration
	`network network`:	RIP Configuration
	`network network`:	ripngd Configuration
	`no agentx`:	MIB and command reference
	`no aggregate-address A.B.C.D/M`:	Route Aggregation
	`no area <0-4294967295> authentication`:	OSPF area
	`no area <0-4294967295> export-list NAME`:	OSPF area
	`no area <0-4294967295> filter-list prefix NAME in`:	OSPF area
	`no area <0-4294967295> filter-list prefix NAME out`:	OSPF area
	`no area <0-4294967295> import-list NAME`:	OSPF area
	`no area <0-4294967295> range a.b.c.d/m`:	OSPF area
	`no area <0-4294967295> shortcut`:	OSPF area
	`no area <0-4294967295> stub`:	OSPF area
	`no area <0-4294967295> stub no-summary`:	OSPF area
	`no area <0-4294967295> virtual-link a.b.c.d`:	OSPF area
	`no area a.b.c.d authentication`:	OSPF area
	`no area a.b.c.d default-cost <0-16777215>`:	OSPF area
	`no area a.b.c.d export-list NAME`:	OSPF area
	`no area a.b.c.d filter-list prefix NAME in`:	OSPF area
	`no area a.b.c.d filter-list prefix NAME out`:	OSPF area
	`no area a.b.c.d import-list NAME`:	OSPF area
	`no area a.b.c.d range a.b.c.d/m`:	OSPF area
	`no area a.b.c.d range IPV4_PREFIX not-advertise`:	OSPF area
	`no area a.b.c.d range IPV4_PREFIX substitute IPV4_PREFIX`:	OSPF area
	`no area a.b.c.d shortcut`:	OSPF area
	`no area a.b.c.d stub`:	OSPF area
	`no area a.b.c.d stub no-summary`:	OSPF area
	`no area a.b.c.d virtual-link a.b.c.d`:	OSPF area
	`no area-password`:	ISIS router
	`no auto-cost reference-bandwidth`:	OSPF router
	`no auto-cost reference-bandwidth`:	OSPF6 router
	`no bandwidth <1-10000000>`:	Standard Commands
	`no banner motd`:	Basic Config Commands
	`no bgp multiple-instance`:	Multiple instance
	`no capability opaque`:	Opaque LSA
	`no debug event`:	More Show IP BGP
	`no debug isis adj-packets`:	Debugging ISIS
	`no debug isis checksum-errors`:	Debugging ISIS
	`no debug isis events`:	Debugging ISIS
	`no debug isis local-updates`:	Debugging ISIS
	`no debug isis packet-dump`:	Debugging ISIS
	`no debug isis protocol-errors`:	Debugging ISIS
	`no debug isis route-events`:	Debugging ISIS
	`no debug isis snp-packets`:	Debugging ISIS
	`no debug isis spf-events`:	Debugging ISIS
	`no debug isis spf-statistics`:	Debugging ISIS
	`no debug isis spf-triggers`:	Debugging ISIS
	`no debug isis update-packets`:	Debugging ISIS
	`no debug keepalive`:	More Show IP BGP
	`no debug ospf event`:	Debugging OSPF
	`no debug ospf ism`:	Debugging OSPF
	`no debug ospf ism (status\|events\|timers)`:	Debugging OSPF
	`no debug ospf lsa`:	Debugging OSPF
	`no debug ospf lsa (generate\|flooding\|refresh)`:	Debugging OSPF
	`no debug ospf nsm`:	Debugging OSPF
	`no debug ospf nsm (status\|events\|timers)`:	Debugging OSPF
	`no debug ospf nssa`:	Debugging OSPF
	`no debug ospf packet (hello\|dd\|ls-request\|ls-update\|ls-ack\|all) (send\|recv) [detail]`:	Debugging OSPF
	`no debug ospf te`:	Debugging OSPF
	`no debug ospf zebra`:	Debugging OSPF
	`no debug ospf zebra (interface\|redistribute)`:	Debugging OSPF
	`no debug update`:	More Show IP BGP
	`no default-information originate`:	Redistribute routes to OSPF
	`no default-metric`:	Redistribute routes to OSPF
	`no default-metric <1-16>`:	RIP Metric Manipulation
	`no distance <1-255>`:	RIP distance
	`no distance <1-255>`:	Redistribute routes to OSPF
	`no distance <1-255> A.B.C.D/M`:	RIP distance
	`no distance <1-255> A.B.C.D/M access-list`:	RIP distance
	`no distance ospf`:	Redistribute routes to OSPF
	`no distribute-list NAME out (kernel\|connected\|static\|rip\|ospf`:	Redistribute routes to OSPF
	`no domain-password`:	ISIS router
	`no dump bgp all [path] [interval]`:	Dump BGP packets and table
	`no dump bgp route-mrt [path] [interval]`:	Dump BGP packets and table
	`no dump bgp updates [path] [interval]`:	Dump BGP packets and table
	`no exec-timeout`:	Basic Config Commands
	`no hostname dynamic`:	ISIS router
	`no ip address address/prefix`:	Standard Commands
	`no ip address address/prefix secondary`:	Standard Commands
	`no ip as-path access-list word`:	AS Path Access List
	`no ip as-path access-list word {permit\|deny} line`:	AS Path Access List
	`no ip community-list expanded name`:	BGP Community Lists
	`no ip community-list name`:	BGP Community Lists
	`no ip community-list standard name`:	BGP Community Lists
	`no ip extcommunity-list expanded name`:	BGP Extended Community Lists
	`no ip extcommunity-list name`:	BGP Extended Community Lists
	`no ip extcommunity-list standard name`:	BGP Extended Community Lists
	`no ip mroute prefix nexthop [distance]`:	Multicast RIB Commands
	`no ip multicast rpf-lookup-mode [mode]`:	Multicast RIB Commands
	`no ip ospf area [ADDR]`:	OSPF interface
	`no ip ospf authentication-key`:	OSPF interface
	`no ip ospf cost`:	OSPF interface
	`no ip ospf dead-interval`:	OSPF interface
	`no ip ospf hello-interval`:	OSPF interface
	`no ip ospf message-digest-key`:	OSPF interface
	`no ip ospf network`:	OSPF interface
	`no ip ospf priority`:	OSPF interface
	`no ip ospf retransmit interval`:	OSPF interface
	`no ip ospf transmit-delay`:	OSPF interface
	`no ip prefix-list name`:	IP Prefix List
	`no ip prefix-list name description [desc]`:	ip prefix-list description
	`no ip prefix-list sequence-number`:	ip prefix-list sequential number control
	`no ip rip authentication key-chain key-chain`:	RIP Authentication
	`no ip rip authentication mode md5`:	RIP Authentication
	`no ip rip authentication mode text`:	RIP Authentication
	`no ip rip authentication string string`:	RIP Authentication
	`no ip router isis WORD`:	ISIS interface
	`no ip split-horizon`:	RIP Configuration
	`no ipv6 address address/prefix`:	Standard Commands
	`no ipv6 nd adv-interval-option`:	Router Advertisement
	`no ipv6 nd home-agent-config-flag`:	Router Advertisement
	`no ipv6 nd home-agent-lifetime [<0-65520>]`:	Router Advertisement
	`no ipv6 nd home-agent-preference [<0-65535>]`:	Router Advertisement
	`no ipv6 nd managed-config-flag`:	Router Advertisement
	`no ipv6 nd mtu [<1-65535>]`:	Router Advertisement
	`no ipv6 nd other-config-flag`:	Router Advertisement
	`no ipv6 nd ra-interval [<1-1800>]`:	Router Advertisement
	`no ipv6 nd ra-interval [msec <70-1800000>]`:	Router Advertisement
	`no ipv6 nd ra-lifetime [<0-9000>]`:	Router Advertisement
	`no ipv6 nd reachable-time [<1-3600000>]`:	Router Advertisement
	`no ipv6 nd router-preference [(high\|medium\|low)]`:	Router Advertisement
	`no ipv6 nd suppress-ra`:	Router Advertisement
	`no is-type`:	ISIS region
	`no isis circuit-type`:	ISIS interface
	`no isis csnp-interval`:	ISIS interface
	`no isis csnp-interval [level-1 \| level-2]`:	ISIS interface
	`no isis hello-interval`:	ISIS interface
	`no isis hello-interval [level-1 \| level-2]`:	ISIS interface
	`no isis hello-multiplier`:	ISIS interface
	`no isis hello-multiplier [level-1 \| level-2]`:	ISIS interface
	`no isis metric`:	ISIS interface
	`no isis metric [level-1 \| level-2]`:	ISIS interface
	`no isis network point-to-point`:	ISIS interface
	`no isis passive`:	ISIS interface
	`no isis password`:	ISIS interface
	`no isis priority`:	ISIS interface
	`no isis priority [level-1 \| level-2]`:	ISIS interface
	`no isis psnp-interval`:	ISIS interface
	`no isis psnp-interval [level-1 \| level-2]`:	ISIS interface
	`no link-detect`:	Standard Commands
	`no link-param`:	Link Parameters Commands
	`no log facility`:	Basic Config Commands
	`no log file`:	Basic Config Commands
	`no log monitor`:	Basic Config Commands
	`no log record-priority`:	Basic Config Commands
	`no log stdout`:	Basic Config Commands
	`no log syslog`:	Basic Config Commands
	`no log timestamp precision`:	Basic Config Commands
	`no log trap`:	Basic Config Commands
	`no log-adjacency-changes`:	ISIS router
	`no log-adjacency-changes [detail]`:	OSPF router
	`no lsp-gen-interval`:	ISIS Timer
	`no lsp-gen-interval [level-1 \| level-2]`:	ISIS Timer
	`no lsp-refresh-interval`:	ISIS Timer
	`no lsp-refresh-interval`:	ISIS Timer
	`no lsp-refresh-interval [level-1 \| level-2]`:	ISIS Timer
	`no lsp-refresh-interval [level-1 \| level-2]`:	ISIS Timer
	`no max-lsp-lifetime`:	ISIS Timer
	`no max-lsp-lifetime [level-1 \| level-2]`:	ISIS Timer
	`no max-metric router-lsa [on-startup\|on-shutdown\|administrative]`:	OSPF router
	`no metric-style`:	ISIS router
	`no mpls-te`:	OSPF Traffic Engineering
	`no mpls-te`:	OSPF Traffic Engineering
	`no mpls-te`:	ISIS Traffic Engineering
	`no mpls-te inter-as`:	OSPF Traffic Engineering
	`no mpls-te router-address`:	ISIS Traffic Engineering
	`no multicast`:	Standard Commands
	`no neighbor`:	Link Parameters Commands
	`no neighbor a.b.c.d`:	RIP Configuration
	`no neighbor peer default-originate`:	BGP Peer commands
	`no neighbor peer description ...`:	BGP Peer commands
	`no neighbor peer dont-capability-negotiate`:	Capability Negotiation
	`no neighbor peer ebgp-multihop`:	BGP Peer commands
	`no neighbor peer interface ifname`:	BGP Peer commands
	`no neighbor peer local-as`:	BGP Peer commands
	`no neighbor peer maximum-prefix number`:	BGP Peer commands
	`no neighbor peer next-hop-self [all]`:	BGP Peer commands
	`no neighbor peer override-capability`:	Capability Negotiation
	`no neighbor peer route-reflector-client`:	Route Reflector
	`no neighbor peer shutdown`:	BGP Peer commands
	`no neighbor peer strict-capability-match`:	Capability Negotiation
	`no neighbor peer ttl-security hops number`:	BGP Peer commands
	`no neighbor peer update-source`:	BGP Peer commands
	`no neighbor peer weight weight`:	BGP Peer commands
	`no net XX.XXXX. ... .XXX.XX`:	ISIS router
	`no network A.B.C.D/M`:	BGP route
	`no network a.b.c.d/m area <0-4294967295>`:	OSPF router
	`no network a.b.c.d/m area a.b.c.d`:	OSPF router
	`no network ifname`:	RIP Configuration
	`no network network`:	RIP Configuration
	`no ospf abr-type type`:	OSPF router
	`no ospf opaque-lsa`:	Opaque LSA
	`no ospf rfc1583compatibility`:	OSPF router
	`no ospf router-id`:	OSPF router
	`no passive-interface IFNAME`:	RIP Configuration
	`no passive-interface interface`:	OSPF router
	`no pce address`:	Router Information
	`no pce domain as <0-65535>`:	Router Information
	`no pce flag`:	Router Information
	`no pce neighbor as <0-65535>`:	Router Information
	`no pce scope`:	Router Information
	`no redistribute (kernel\|connected\|static\|rip\|bgp)`:	Redistribute routes to OSPF
	`no redistribute bgp`:	How to Announce RIP route
	`no redistribute connected`:	How to Announce RIP route
	`no redistribute kernel`:	How to Announce RIP route
	`no redistribute ospf`:	How to Announce RIP route
	`no redistribute static`:	How to Announce RIP route
	`no route a.b.c.d/m`:	How to Announce RIP route
	`no router bgp asn`:	BGP router
	`no router isis WORD`:	ISIS router
	`no router ospf`:	OSPF router
	`no router rip`:	RIP Configuration
	`no router-info`:	Router Information
	`no set-overload-bit`:	ISIS router
	`no shutdown`:	Standard Commands
	`no smux peer oid`:	MIB and command reference
	`no smux peer oid password`:	MIB and command reference
	`no spf-interval`:	ISIS Timer
	`no spf-interval [level-1 \| level-2]`:	ISIS Timer
	`no timers basic`:	RIP Timers
	`no timers throttle spf`:	OSPF router
	`no timers throttle spf`:	OSPF6 router
	`no version`:	RIP Version Control

O
	`offset-list access-list (in\|out)`:	RIP Metric Manipulation
	`offset-list access-list (in\|out) ifname`:	RIP Metric Manipulation
	`on-match goto N`:	Route Map Exit Action Command
	`on-match next`:	Route Map Exit Action Command
	`ospf abr-type type`:	OSPF router
	`ospf opaque-lsa`:	Opaque LSA
	`ospf rfc1583compatibility`:	OSPF router
	`ospf router-id a.b.c.d`:	OSPF router

P
	`packet-loss percentage`:	Link Parameters Commands
	`passive-interface (IFNAME\|default)`:	RIP Configuration
	`passive-interface interface`:	OSPF router
	`password password`:	Basic Config Commands
	`pce address <A.B.C.D>`:	Router Information
	`pce domain as <0-65535>`:	Router Information
	`pce flag BITPATTERN`:	Router Information
	`pce neighbor as <0-65535>`:	Router Information
	`pce scope BITPATTERN`:	Router Information

R
	`redistribute (kernel\|connected\|static\|rip\|bgp)`:	Redistribute routes to OSPF
	`redistribute (kernel\|connected\|static\|rip\|bgp) metric <0-16777214>`:	Redistribute routes to OSPF
	`redistribute (kernel\|connected\|static\|rip\|bgp) metric <0-16777214> route-map word`:	Redistribute routes to OSPF
	`redistribute (kernel\|connected\|static\|rip\|bgp) metric-type (1\|2)`:	Redistribute routes to OSPF
	`redistribute (kernel\|connected\|static\|rip\|bgp) metric-type (1\|2) metric <0-16777214>`:	Redistribute routes to OSPF
	`redistribute (kernel\|connected\|static\|rip\|bgp) metric-type (1\|2) metric <0-16777214> route-map word`:	Redistribute routes to OSPF
	`redistribute (kernel\|connected\|static\|rip\|bgp) metric-type (1\|2) route-map word`:	Redistribute routes to OSPF
	`redistribute (kernel\|connected\|static\|rip\|bgp) route-map`:	Redistribute routes to OSPF
	`redistribute bgp`:	How to Announce RIP route
	`redistribute bgp metric <0-16>`:	How to Announce RIP route
	`redistribute bgp route-map route-map`:	How to Announce RIP route
	`redistribute connected`:	How to Announce RIP route
	`redistribute connected`:	Redistribute routes to OSPF6
	`redistribute connected`:	Redistribute to BGP
	`redistribute connected metric <0-16>`:	How to Announce RIP route
	`redistribute connected route-map route-map`:	How to Announce RIP route
	`redistribute kernel`:	How to Announce RIP route
	`redistribute kernel`:	Redistribute to BGP
	`redistribute kernel metric <0-16>`:	How to Announce RIP route
	`redistribute kernel route-map route-map`:	How to Announce RIP route
	`redistribute ospf`:	How to Announce RIP route
	`redistribute ospf`:	Redistribute to BGP
	`redistribute ospf metric <0-16>`:	How to Announce RIP route
	`redistribute ospf route-map route-map`:	How to Announce RIP route
	`redistribute rip`:	Redistribute to BGP
	`redistribute ripng`:	Redistribute routes to OSPF6
	`redistribute static`:	How to Announce RIP route
	`redistribute static`:	Redistribute routes to OSPF6
	`redistribute static`:	Redistribute to BGP
	`redistribute static metric <0-16>`:	How to Announce RIP route
	`redistribute static route-map route-map`:	How to Announce RIP route
	`res-bw bandwidth`:	Link Parameters Commands
	`route a.b.c.d/m`:	How to Announce RIP route
	`route network`:	ripngd Configuration
	`route-map route-map-name (permit\|deny) order`:	Route Map Command
	`router bgp as-number`:	BGP instance and view
	`router bgp as-number view name`:	BGP instance and view
	`router bgp asn`:	BGP router
	`router isis WORD`:	ISIS router
	`router ospf`:	OSPF router
	`router ospf6`:	OSPF6 router
	`router rip`:	RIP Configuration
	`router ripng`:	ripngd Configuration
	`router zebra`:	ripngd Configuration
	`router-id a.b.c.d`:	OSPF6 router
	`router-info [as \| area <A.B.C.D>]`:	Router Information

S
	`service advanced-vty`:	Basic Config Commands
	`service integrated-vtysh-config`:	VTY shell integrated configuration
	`service password-encryption`:	Basic Config Commands
	`service terminal-length <0-512>`:	Basic Config Commands
	`set as-path prepend as-path`:	Using AS Path in Route Map
	`set as-path prepend as_path`:	Route Map Set Command
	`set as-path prepend last-as num`:	Using AS Path in Route Map
	`set comm-list word delete`:	BGP Community in Route Map
	`set community community`:	BGP Community in Route Map
	`set community community`:	Route Map Set Command
	`set community community additive`:	BGP Community in Route Map
	`set community none`:	BGP Community in Route Map
	`set extcommunity rt extcommunity`:	BGP Extended Communities in Route Map
	`set extcommunity soo extcommunity`:	BGP Extended Communities in Route Map
	`set ip next-hop A.B.C.D`:	RIP route-map
	`set ip next-hop ipv4_address`:	Route Map Set Command
	`set ipv6 next-hop global ipv6_address`:	Route Map Set Command
	`set ipv6 next-hop local ipv6_address`:	Route Map Set Command
	`set local-preference local_pref`:	Route Map Set Command
	`set metric <0-4294967295>`:	RIP route-map
	`set metric metric`:	Route Map Set Command
	`set src address`:	zebra Route Filtering
	`set weight weight`:	Route Map Set Command
	`set-overload-bit`:	ISIS router
	`show bgp ipv4 encap summary`:	BGP Address Family
	`show bgp ipv4 vpn summary`:	BGP Address Family
	`show bgp ipv6 encap summary`:	BGP Address Family
	`show bgp ipv6 vpn summary`:	BGP Address Family
	`show debug`:	More Show IP BGP
	`show debugging isis`:	Debugging ISIS
	`show debugging ospf`:	Debugging OSPF
	`show debugging rip`:	RIP Debug Commands
	`show debugging ripng`:	ripngd Terminal Mode Commands
	`show interface`:	zebra Terminal Mode Commands
	`show ip bgp`:	Show IP BGP
	`show ip bgp A.B.C.D`:	Show IP BGP
	`show ip bgp community`:	Display BGP Routes by Community
	`show ip bgp community community`:	Display BGP Routes by Community
	`show ip bgp community community`:	More Show IP BGP
	`show ip bgp community community exact-match`:	Display BGP Routes by Community
	`show ip bgp community community exact-match`:	More Show IP BGP
	`show ip bgp community-list word`:	Display BGP Routes by Community
	`show ip bgp community-list word`:	More Show IP BGP
	`show ip bgp community-list word exact-match`:	Display BGP Routes by Community
	`show ip bgp community-list word exact-match`:	More Show IP BGP
	`show ip bgp dampened-paths`:	More Show IP BGP
	`show ip bgp encap all`:	BGP Address Family
	`show ip bgp flap-statistics`:	More Show IP BGP
	`show ip bgp neighbor [peer]`:	More Show IP BGP
	`show ip bgp regexp line`:	Display BGP Routes by AS Path
	`show ip bgp regexp line`:	More Show IP BGP
	`show ip bgp summary`:	More Show IP BGP
	`show ip bgp view name`:	Viewing the view
	`show ip bgp vpnv4 all`:	BGP Address Family
	`show ip bgp X:X::X:X`:	Show IP BGP
	`show ip community-list`:	BGP Community Lists
	`show ip community-list name`:	BGP Community Lists
	`show ip extcommunity-list`:	BGP Extended Community Lists
	`show ip extcommunity-list name`:	BGP Extended Community Lists
	`show ip ospf`:	Showing OSPF information
	`show ip ospf database`:	Showing OSPF information
	`show ip ospf database (opaque-link\|opaque-area\|opaque-external)`:	Opaque LSA
	`show ip ospf database (opaque-link\|opaque-area\|opaque-external) adv-router adv-router`:	Opaque LSA
	`show ip ospf database (opaque-link\|opaque-area\|opaque-external) link-state-id`:	Opaque LSA
	`show ip ospf database (opaque-link\|opaque-area\|opaque-external) link-state-id adv-router adv-router`:	Opaque LSA
	`show ip ospf database (opaque-link\|opaque-area\|opaque-external) link-state-id self-originate`:	Opaque LSA
	`show ip ospf database (opaque-link\|opaque-area\|opaque-external) self-originate`:	Opaque LSA
	`show ip ospf database … adv-router adv-router`:	Showing OSPF information
	`show ip ospf database … link-state-id`:	Showing OSPF information
	`show ip ospf database … link-state-id adv-router adv-router`:	Showing OSPF information
	`show ip ospf database … link-state-id self-originate`:	Showing OSPF information
	`show ip ospf database … self-originate`:	Showing OSPF information
	`show ip ospf database asbr-router`:	Showing OSPF information
	`show ip ospf database asbr-summary`:	Showing OSPF information
	`show ip ospf database external`:	Showing OSPF information
	`show ip ospf database max-age`:	Showing OSPF information
	`show ip ospf database network`:	Showing OSPF information
	`show ip ospf database self-originate`:	Showing OSPF information
	`show ip ospf database summary`:	Showing OSPF information
	`show ip ospf interface [INTERFACE]`:	Showing OSPF information
	`show ip ospf mpls-te interface`:	OSPF Traffic Engineering
	`show ip ospf mpls-te interface interface`:	OSPF Traffic Engineering
	`show ip ospf mpls-te router`:	OSPF Traffic Engineering
	`show ip ospf neighbor`:	Showing OSPF information
	`show ip ospf neighbor detail`:	Showing OSPF information
	`show ip ospf neighbor INTERFACE`:	Showing OSPF information
	`show ip ospf neighbor INTERFACE detail`:	Showing OSPF information
	`show ip ospf route`:	Showing OSPF information
	`show ip ospf router-info`:	Router Information
	`show ip ospf router-info pce`:	Router Information
	`show ip prefix-list`:	Showing ip prefix-list
	`show ip prefix-list detail`:	Showing ip prefix-list
	`show ip prefix-list detail name`:	Showing ip prefix-list
	`show ip prefix-list name`:	Showing ip prefix-list
	`show ip prefix-list name a.b.c.d/m`:	Showing ip prefix-list
	`show ip prefix-list name a.b.c.d/m first-match`:	Showing ip prefix-list
	`show ip prefix-list name a.b.c.d/m longer`:	Showing ip prefix-list
	`show ip prefix-list name seq num`:	Showing ip prefix-list
	`show ip prefix-list summary`:	Showing ip prefix-list
	`show ip prefix-list summary name`:	Showing ip prefix-list
	`show ip prefix-list [name]`:	zebra Terminal Mode Commands
	`show ip protocol`:	zebra Terminal Mode Commands
	`show ip rip`:	Show RIP Information
	`show ip rip status`:	Show RIP Information
	`show ip ripng`:	ripngd Terminal Mode Commands
	`show ip route`:	zebra Terminal Mode Commands
	`show ip route isis`:	Showing ISIS information
	`show ip rpf`:	Multicast RIB Commands
	`show ip rpf addr`:	Multicast RIB Commands
	`show ipforward`:	zebra Terminal Mode Commands
	`show ipv6 bgp encap all`:	BGP Address Family
	`show ipv6 bgp vpn all`:	BGP Address Family
	`show ipv6 ospf6 database`:	Showing OSPF6 information
	`show ipv6 ospf6 interface`:	Showing OSPF6 information
	`show ipv6 ospf6 neighbor`:	Showing OSPF6 information
	`show ipv6 ospf6 request-list A.B.C.D`:	Showing OSPF6 information
	`show ipv6 ospf6 [INSTANCE_ID]`:	Showing OSPF6 information
	`show ipv6 route`:	zebra Terminal Mode Commands
	`show ipv6 route ospf6`:	Showing OSPF6 information
	`show ipv6forward`:	zebra Terminal Mode Commands
	`show isis database`:	Showing ISIS information
	`show isis database <LSP id> [detail]`:	Showing ISIS information
	`show isis database detail <LSP id>`:	Showing ISIS information
	`show isis database [detail]`:	Showing ISIS information
	`show isis hostname`:	Showing ISIS information
	`show isis interface`:	Showing ISIS information
	`show isis interface <interface name>`:	Showing ISIS information
	`show isis interface detail`:	Showing ISIS information
	`show isis mpls-te interface`:	ISIS Traffic Engineering
	`show isis mpls-te interface interface`:	ISIS Traffic Engineering
	`show isis mpls-te router`:	ISIS Traffic Engineering
	`show isis neighbor`:	Showing ISIS information
	`show isis neighbor <System Id>`:	Showing ISIS information
	`show isis neighbor detail`:	Showing ISIS information
	`show isis summary`:	Showing ISIS information
	`show isis topology`:	Showing ISIS information
	`show isis topology [level-1\|level-2]`:	Showing ISIS information
	`show logging`:	Terminal Mode Commands
	`show route-map [name]`:	zebra Terminal Mode Commands
	`show version`:	Terminal Mode Commands
	`show zebra fpm stats`:	zebra Terminal Mode Commands
	`shutdown`:	Standard Commands
	`smux peer oid`:	MIB and command reference
	`smux peer oid password`:	MIB and command reference
	`spf-interval <1-120>`:	ISIS Timer
	`spf-interval [level-1 \| level-2] <1-120>`:	ISIS Timer

T
	`table tableno`:	Static Route Commands
	`terminal length <0-512>`:	Terminal Mode Commands
	`timers basic update timeout garbage`:	RIP Timers
	`timers throttle spf delay initial-holdtime max-holdtime`:	OSPF router
	`timers throttle spf delay initial-holdtime max-holdtime`:	OSPF6 router

U
	`unrsv-bw <0-7> bandwidth`:	Link Parameters Commands
	`use-bw bandwidth`:	Link Parameters Commands
	`username username nopassword`:	VTY shell username

V
	`version version`:	RIP Version Control

W
	`who`:	Terminal Mode Commands
	`write file`:	Terminal Mode Commands
	`write terminal`:	Terminal Mode Commands

Jump to:	A B C D E F H I L M N O P R S T U V W

VTY Key Index

Jump to:	? C D L M R T U

	Index Entry	Section

?
	`?`:	CLI Advanced Commands

C
	`C-a`:	CLI Movement Commands
	`C-b`:	CLI Movement Commands
	`C-c`:	CLI Advanced Commands
	`C-d`:	CLI Editing Commands
	`C-e`:	CLI Movement Commands
	`C-f`:	CLI Movement Commands
	`C-h`:	CLI Editing Commands
	`C-k`:	CLI Editing Commands
	`C-n`:	CLI Advanced Commands
	`C-p`:	CLI Advanced Commands
	`C-t`:	CLI Editing Commands
	`C-u`:	CLI Editing Commands
	`C-v`:	CLI Editing Commands
	`C-w`:	CLI Editing Commands
	`C-z`:	CLI Advanced Commands

D
	`DEL`:	CLI Editing Commands
	`DOWN`:	CLI Advanced Commands

L
	`LEFT`:	CLI Movement Commands

M
	`M-b`:	CLI Movement Commands
	`M-d`:	CLI Editing Commands
	`M-f`:	CLI Movement Commands

R
	`RIGHT`:	CLI Movement Commands

T
	`TAB`:	CLI Advanced Commands

U
	`UP`:	CLI Advanced Commands

Jump to:	? C D L M R T U

Index

Jump to:	A B C D E F G H I L M N O Q R S

	Index Entry	Section

A
	About Quagga:	About Quagga

B
	Bug hunting:	Bug Reports
	Bug Reports:	Bug Reports
	Build options:	The Configure script and its options
	Building on Linux boxes:	Linux notes
	Building the system:	Installation

C
	Compatibility with other systems:	Supported Platforms
	Configuration files for running the software:	Config Commands
	Configuration options:	The Configure script and its options
	Configuring Quagga:	Linux notes
	Contact information:	Mailing List

D
	Distance-vector routing protocol:	OSPF Fundamentals
	Distribution configuration:	The Configure script and its options

E
	Errors in the software:	Bug Reports

F
	Files for running configurations:	Config Commands
	Found a bug?:	Bug Reports

G
	Getting the herd running:	Config Commands

H
	How to get in touch with Quagga:	Mailing List
	How to install Quagga:	Installation

I
	Installation:	Installation
	Installing Quagga:	Installation
	ISIS:	OSPF6 Configuration Examples

L
	Link State Advertisement:	OSPF Fundamentals
	Link State Announcement:	OSPF Fundamentals
	Link State DataBase:	OSPF Fundamentals
	Link-state routing protocol:	OSPF Fundamentals
	Link-state routing protocol advantages:	OSPF Fundamentals
	Link-state routing protocol disadvantages:	OSPF Fundamentals
	Linux configurations:	Linux notes
	LSA flooding:	OSPF Fundamentals

M
	Mailing lists:	Mailing List
	Mailing Quagga:	Mailing List
	Making Quagga:	Installation
	Modifying the herd’s behavior:	Config Commands

N
	NHRP:	ISIS Configuration Examples

O
	Operating systems that support Quagga:	Supported Platforms
	Options for configuring:	The Configure script and its options
	Options to `./configure`:	The Configure script and its options
	OSPF Areas overview:	OSPF Fundamentals
	OSPF Fundamentals:	OSPFv2
	OSPF Hello Protocol:	OSPF Fundamentals
	OSPF Hello Protocol overview:	OSPF Fundamentals
	OSPF LSA overview:	OSPF Fundamentals
	OSPFv2:	ripngd Filtering Commands
	Overview:	Overview

Q
	Quagga Least-Privileges:	Least-Privilege support
	Quagga on other systems:	Supported Platforms
	Quagga Privileges:	Least-Privilege support

R
	Reporting bugs:	Bug Reports
	Reporting software errors:	Bug Reports

S
	Software architecture:	System Architecture
	Software internals:	System Architecture
	Supported platforms:	Supported Platforms
	System architecture:	System Architecture

Jump to:	A B C D E F G H I L M N O Q R S

Footnotes

(1)

GNU/Linux has very flexible kernel configuration features

(2)

For some set of objects to havean order, there must be some binary ordering relation that is definedfor every combination of those objects, and that relation mustbe transitive. I.e., if the relation operator is â‰º, and if a â‰º b and b â‰º c then that relation must carry overand it must be that a â‰º c for the objects to have anorder. The ordering relation may allow for equality, i.e. a â‰º b and b â‰º a may both be true amd imply thata and b are equal in the order and not distinguished by it, inwhich case the set has a partial order. Otherwise, if there is an order,all the objects have a distinct place in the order and the set has a totalorder.

posted @ 2017-04-25 21:27 张同光阅读(213) 评论(0) 编辑收藏举报

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• Overview:
• Installation:
• Basic commands:
• Zebra:
• RIP:
• RIPng:
• OSPFv2:
• OSPFv3:
• ISIS:
• NHRP:
• BGP:
• Configuring Quagga as a Route Server:
• VTY shell:
• Filtering:
• Route Map:
• IPv6 Support:
• Kernel Interface:
• SNMP Support:
• Zebra Protocol:
• Packet Binary Dump Format:
• Command Index:
• VTY Key Index:
• Index:

• About Quagga:		Basic information about Quagga
• System Architecture:		The Quagga system architecture
• Supported Platforms:		Supported platforms and future plans
• Supported RFCs:		Supported RFCs
• How to get Quagga:
• Mailing List:		Mailing list information
• Bug Reports:		Mail address for bug data

• Config Commands:		Commands used in config files
• Terminal Mode Commands:		Common commands used in a VTY
• Common Invocation Options:		Starting the daemons
• Virtual Terminal Interfaces:		Interacting with the daemons

• Basic Config Commands:		Some of the generic config commands
• Sample Config File:		An example config file

• VTY Overview:		Basics about VTYs
• VTY Modes:		View, Enable, and Other VTY modes
• VTY CLI Commands:		Commands for movement, edition, and management

• Configure the Software:
• Build the Software:
• Install the Software:

• The Configure script and its options:
• Least-Privilege support:
• Linux notes:

• VTY View Mode:		Mode for read-only interaction
• VTY Enable Mode:		Mode for read-write interaction
• VTY Other Modes:		Special modes (tftp, etc)

• CLI Movement Commands:		Commands for moving the cursor about
• CLI Editing Commands:		Commands for changing text
• CLI Advanced Commands:		Other commands, session management and so on

• Invoking zebra:		Running the program
• Interface Commands:		Commands for zebra interfaces
• Static Route Commands:		Commands for adding static routes
• Multicast RIB Commands:		Commands for controlling MRIB behavior
• zebra Route Filtering:		Commands for zebra route filtering
• zebra FIB push interface:		Interface to optional FPM component
• zebra Terminal Mode Commands:		Commands for zebra’s VTY

• Starting and Stopping ripd:
• RIP Configuration:
• RIP Version Control:
• How to Announce RIP route:
• Filtering RIP Routes:
• RIP Metric Manipulation:
• RIP distance:
• RIP route-map:
• RIP Authentication:
• RIP Timers:
• Show RIP Information:
• RIP Debug Commands:

• Invoking ripngd:
• ripngd Configuration:
• ripngd Terminal Mode Commands:
• ripngd Filtering Commands:

• OSPF Fundamentals:
• Configuring ospfd:
• OSPF router:
• OSPF area:
• OSPF interface:
• Redistribute routes to OSPF:
• Showing OSPF information:
• Opaque LSA:
• OSPF Traffic Engineering:
• Router Information:
• Debugging OSPF:
• OSPF Configuration Examples:

• OSPF6 router:
• OSPF6 area:
• OSPF6 interface:
• Redistribute routes to OSPF6:
• Showing OSPF6 information:
• OSPF6 Configuration Examples:

• Configuring isisd:
• ISIS router:
• ISIS Timer:
• ISIS region:
• ISIS interface:
• Showing ISIS information:
• ISIS Traffic Engineering:
• Debugging ISIS:
• ISIS Configuration Examples:

• Routing Design:
• Configuring NHRP:
• Hub Functionality:
• Integration with IKE:
• NHRP Events:
• Configuration Example:

• Starting BGP:
• BGP router:
• BGP MED:
• BGP network:
• BGP Peer:
• BGP Peer Group:
• BGP Address Family:
• Autonomous System:
• BGP Communities Attribute:
• BGP Extended Communities Attribute:
• Displaying BGP routes:
• Capability Negotiation:
• Route Reflector:
• Route Server:
• How to set up a 6-Bone connection:
• Dump BGP packets and table:
• BGP Configuration Examples:

• BGP distance:
• BGP decision process:
• BGP route flap dampening:

• BGP route:
• Route Aggregation:
• Redistribute to BGP:

• AS Path Regular Expression:
• Display BGP Routes by AS Path:
• AS Path Access List:
• Using AS Path in Route Map:
• Private AS Numbers:

• BGP Community Lists:
• Numbered BGP Community Lists:
• BGP Community in Route Map:
• Display BGP Routes by Community:
• Using BGP Communities Attribute:

• BGP Extended Community Lists:
• BGP Extended Communities in Route Map:

• Multiple instance:
• BGP instance and view:
• Routing policy:
• Viewing the view:

• Description of the Route Server model:
• Commands for configuring a Route Server:
• Example of Route Server Configuration:

• Configuration of the BGP routers without Route Server:
• Configuration of the BGP routers with Route Server:
• Configuration of the Route Server itself:
• Further considerations about Import and Export route-maps:

张同光 (Tongguang Zhang)