静态路由与BFD联动实现快速检测链路状态使路由表快速收敛

 实现目的：

1.默认情况，PC1和PC2之间的通信使用AR1-AR9-AR10-AR2链路通信（主链路），当AR1-AR9-AR10-AR2链路中任何一点的链路断开后，路由会以毫秒级速度切换到AR1-AR3-AR2（备链路），实现网络的连通性。

2.当主链路恢复后，路由又切回到主线路。

 

实验前的配置基础：

1.配置PC和路由器端口IP；

2.添加静态路由，实现PC1到PC2网络可达。

3.然后创建BFD，绑定到路由上。

开启BFD
[AR1]bfd
[AR1-bfd]q

配置BFD的源地址，目的地址
[AR1]bfd abc bind peer-ip 10.0.33.2 source-ip 10.0.12.2 auto

绑定到主路由上，当BFD检测失败后，会把这个路由给删掉，然后ip route-static 192.168.50.0 255.255.255.0 10.0.13.3 preference 70这条浮动路由会生效。
[AR1]ip route-static 192.168.50.0 255.255.255.0 10.0.12.2 track bfd-session abc

　AR2路由器上的配置同上。

 

实现技术：使用BFD（双向转发检测）技术，说的直白点，就是在末端路由器上开启BFD，两端都要开启，设置BFD，将BFD绑定到静态路由，每100毫秒（时间可以自定义）发送一个BFD检测包，当链路断开后，BFD检测状态从UP变为DOWN,路由快速收敛，备份路由（浮动路由）成为主路由。

 

路由器和PC配置如下：

 

AR1配置：

[AR1]display current-configuration 
[V200R003C00]
#
 sysname AR1
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load flash:/portalpage.zip
#
 drop illegal-mac alarm
#
 wlan ac-global carrier id other ac id 0
#
 set cpu-usage threshold 80 restore 75
#
bfd
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 192.168.40.254 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 10.0.12.1 255.255.255.0 
#
interface GigabitEthernet0/0/2
 ip address 10.0.13.1 255.255.255.0 
#
interface NULL0
#
bfd aa bind peer-ip 10.0.12.2 source-ip 10.0.12.1 auto
 min-tx-interval 100
 min-rx-interval 100
 commit
#
bfd abc bind peer-ip 10.0.33.2 source-ip 10.0.12.1 auto
 min-tx-interval 100
 min-rx-interval 100
 commit
#
ip route-static 10.0.33.0 255.255.255.0 10.0.12.2
ip route-static 10.0.34.0 255.255.255.0 10.0.12.2
ip route-static 192.168.50.0 255.255.255.0 10.0.13.3 preference 70
ip route-static 192.168.50.0 255.255.255.0 10.0.12.2 track bfd-session abc
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

　AR1上查看bfd的状态：

 AR9配置：

[AR9]display current-configuration 
[V200R003C00]
#
 sysname AR9
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
 drop illegal-mac alarm
#
 set cpu-usage threshold 80 restore 75
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 10.0.12.2 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 10.0.34.1 255.255.255.0 
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
ip route-static 10.0.33.0 255.255.255.0 10.0.34.2
ip route-static 192.168.40.0 255.255.255.0 10.0.12.1
ip route-static 192.168.50.0 255.255.255.0 10.0.34.2
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

AR10配置：

[AR10]display current-configuration 
[V200R003C00]
#
 sysname AR10
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
 drop illegal-mac alarm
#
 set cpu-usage threshold 80 restore 75
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 10.0.33.1 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 10.0.34.2 255.255.255.0 
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
ip route-static 10.0.12.0 255.255.255.0 10.0.34.1
ip route-static 192.168.40.0 255.255.255.0 10.0.34.1
ip route-static 192.168.50.0 255.255.255.0 10.0.33.2
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

　　

AR2配置：

[AR2]display current-configuration 
[V200R003C00]
#
 sysname AR2
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load flash:/portalpage.zip
#
 drop illegal-mac alarm
#
 wlan ac-global carrier id other ac id 0
#
 set cpu-usage threshold 80 restore 75
#
bfd
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 10.0.33.2 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 192.168.50.254 255.255.255.0 
#
interface GigabitEthernet0/0/2
 ip address 10.0.23.2 255.255.255.0 
#
interface NULL0
#
bfd ar2-ar1 bind peer-ip 10.0.12.1 source-ip 10.0.12.2
 discriminator local 1
 discriminator remote 2
 min-rx-interval 100
 commit
#
bfd bb bind peer-ip 10.0.12.1 source-ip 10.0.12.2 auto
 min-tx-interval 100
 min-rx-interval 100
 commit
#
bfd def bind peer-ip 10.0.12.1 source-ip 10.0.33.2 auto
 min-tx-interval 100
 min-rx-interval 100
 commit
#
ip route-static 10.0.12.0 255.255.255.0 10.0.33.1
ip route-static 10.0.34.0 255.255.255.0 10.0.33.1
ip route-static 192.168.40.0 255.255.255.0 10.0.23.3 preference 70
ip route-static 192.168.40.0 255.255.255.0 10.0.33.1 track bfd-session def
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

 

在AR2上查看bfd状态：

 

AR3配置：

[AR3]display current-configuration 
[V200R003C00]
#
 sysname AR3
#
 snmp-agent local-engineid 800007DB03000000000000
 snmp-agent 
#
 clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load flash:/portalpage.zip
#
 drop illegal-mac alarm
#
 wlan ac-global carrier id other ac id 0
#
 set cpu-usage threshold 80 restore 75
#
aaa 
 authentication-scheme default
 authorization-scheme default
 accounting-scheme default
 domain default 
 domain default_admin 
 local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
 local-user admin service-type http
#
firewall zone Local
 priority 15
#
interface GigabitEthernet0/0/0
 ip address 10.0.13.3 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 10.0.23.3 255.255.255.0 
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
ip route-static 10.0.40.0 255.255.255.0 10.0.13.1
ip route-static 10.0.50.0 255.255.255.0 10.0.23.2
ip route-static 192.168.40.0 255.255.255.0 10.0.13.1
ip route-static 192.168.50.0 255.255.255.0 10.0.23.2
#
user-interface con 0
 authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

　　

PC1配置：

 PC2配置：

 

验证：

默认路由跟踪：

 

把AR9的ge0/0/1关闭调后，路由跟踪：