VTP
1、 MAC地址表：
查找交换机端口哪一个端口的MAC地址是0010.5a0c.ffba。 # show mac address
sw-ac3#show mac-address-table
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
33 0010.5a0c.ffba DYNAMIC Fa0/1
2 、Trunk口：
查找交换机的Trunk接口。 # show interfaces trunk
sw-ac3#show interfaces trunk
Port Mode Encapsulation Status Native vlan
Fa0/3 on 802.1q trunking 1
Fa0/9 on 802.1q trunking 1
Fa0/12 on 802.1q trunking 1
Port Vlans allowed on trunk
Fa0/3 1-1005
Fa0/9 1-1005
Fa0/12 1-1005
Port Vlans allowed and active in management domain
Fa0/3 1,22,33,44,99
Fa0/9 1,22,33,44,99
Fa0/12 1,22,33,44,99
Port Vlans in spanning tree forwarding state and not pruned
Fa0/3 1,22,33,44,99
Fa0/9 1,22,44,99
Fa0/12 33
3、 路由器型号：
查看 vlan-r1 路由器的型号。 # show cdp neighbors
sw-ac3#show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
sw-ds1 Fas 0/12 164 S 2960 Fas 0/3
sw-ac2 Fas 0/9 164 S 2960 Fas 0/7
vlan-r1 Fas 0/3 164 R C2800 Fas 0/0
vlan-r1 Fas 0/3 164 R C2800 Fas 0/0.1
vlan-r1 Fas 0/3 164 R C2800 Fas 0/0.22
vlan-r1 Fas 0/3 164 R C2800 Fas 0/0.33
vlan-r1 Fas 0/3 164 R C2800 Fas 0/0.44
4、根桥交换机：
查找作为Vlan1根桥的交换机。 # show spanning-tree vlan 1
sw-ac3#show spanning-tree vlan 1
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 24577
Address 0010.1102.14C4
Cost 19
Port 9(FastEthernet0/9)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 00E0.F768.81B1
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 20
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/3 Desg FWD 19 128.3 P2p
Fa0/9 Root FWD 19 128.9 P2p
Fa0/12 Altn BLK 19 128.12 P2p
~~~~
"Port 9(FastEthernet0/9) " 得到与 根桥 链接的端口是Fa0/9,cost=19 下一条就是根桥
而 根端口 的对端交换机肯定是根桥。下一步 用cdp协议确定F0/9的对端设备。
sw-ac3#show cdp n
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
sw-ds1 Fas 0/12 144 S 2960 Fas 0/3
sw-ac2 Fas 0/9 144 S 2960 Fas 0/7
vlan-r1 Fas 0/3 144 R C2800 Fas 0/0
vlan-r1 Fas 0/3 144 R C2800 Fas 0/0.1
vlan-r1 Fas 0/3 144 R C2800 Fas 0/0.22
vlan-r1 Fas 0/3 144 R C2800 Fas 0/0.33
vlan-r1 Fas 0/3 144 R C2800 Fas 0/0.44
~~~~可看到Fa0/9的对端设备是sw-ac2
5 、端口网关：
查找SW-AC3的fa0/4的default-gateway网关地址 (已知Vlan 信息）找出接口所属Vlan ID。 #show vlan
sw-ac3#show vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa0/16
22 servers active
33 Management active Fa0/1, Fa0/2, Fa0/5, Fa0/6
Fa0/7
44 Production active Fa0/4, Fa0/8, Fa0/10, Fa0/11
99 no-where active Fa0/13, Fa0/14, Fa0/15, Fa0/17
Fa0/18, Fa0/19, Fa0/20, Fa0/21
Fa0/22, Fa0/23, Fa0/24, Gig1/1
Gig1/2
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup
~~fa0/4在vlan 44下
6、 服务器IP和设备型号：
找出SW3从哪一台交换机接收Vlan信息（2步）：
1）show vtp status 得知获取VLAN信息的服务器IP地址
2）show cdp neighbord detail 服务器IP所对应的设备型号
sw-ac3#show vtp status
VTP Version : 2
Configuration Revision : 4
Maximum VLANs supported locally : 255
Number of existing VLANs : 9
VTP Operating Mode : Client
VTP Domain Name : home-office
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0x29 0xF2 0x89 0xC3 0x33 0xDC 0x5F 0x0F
Configuration last modified by 192.168.1.249 at 3-1-93 00:53:00
~~从Configuration last modified by 192.168.1.249 at 3-1-93 00:53:00可知VTP的服务器IP地址。第二部查找该IP对应的设备。show cdp neighbors detail
!
Device ID: sw-ac2
Entry address(es):
IP address : 192.168.1.249
Platform: cisco 2960, Capabilities: Switch
Interface: FastEthernet0/9, Port ID (outgoing port): FastEthernet0/7
Holdtime: 142
Version :
Cisco IOS Software, C2960 Software (C2960-LANBASE-M), Version 12.2(25)FX, RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2005 by Cisco Systems, Inc.
Compiled Wed 12-Oct-05 22:05 by pt_team
~~~
7、修订版本号：
通过查看修订版本号 判断讲交换机SW-X通过F0/16接入SW-AC3会导致的后果。
sw-ac3#show vtp status
VTP Version : 2
Configuration Revision : 4 《《《《修订版本号~~
Maximum VLANs supported locally : 255
Number of existing VLANs : 9
VTP Operating Mode : Client
VTP Domain Name : home-office
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0x29 0xF2 0x89 0xC3 0x33 0xDC 0x5F 0x0F
Configuration last modified by 192.168.1.249 at 3-1-93 00:53:00
8、端口查看：
以00d0.d3a1.9a1b为源地址，以000a.8a47.e612为目的地址的数据帧会在交换机SW-AC3从哪些端口转发？
~~如果目的地址帧不在mac地址表中，则会发生泛洪flood，该Vlan内 除 发送端口外，其余端口以及Trunk口都会收到，但是处于block状态的Trunk口，收到后不会转发！
思路： 查看目的mac所属Vlan、找出该Vlan下的端口、删选掉其中处于Block状态的端口。
1）sw-ac3#show mac
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
1 0001.c9e5.be01 DYNAMIC Fa0/3
1 000c.8581.c59b DYNAMIC Fa0/9
1 0010.1102.14c4 DYNAMIC Fa0/9
1 00d0.9746.1686 DYNAMIC Fa0/9
1 00d0.ba9c.db07 DYNAMIC Fa0/9
22 0001.c9e5.be01 DYNAMIC Fa0/3
22 00d0.ba9c.db07 DYNAMIC Fa0/9
22 00e0.f7b0.8998 DYNAMIC Fa0/9
33 0000.0c6a.5547 DYNAMIC Fa0/12
33 0001.63a4.46e1 DYNAMIC Fa0/12
33 0001.c9e5.be01 DYNAMIC Fa0/3
33 0010.5a0c.ffba DYNAMIC Fa0/1
33 0040.0b19.aed1 DYNAMIC Fa0/12
33 0040.0b8a.86a3 DYNAMIC Fa0/12
33 0060.70ad.1603 DYNAMIC Fa0/12
33 00d0.d3a1.9a1b DYNAMIC Fa0/6
33 00e0.a396.b701 DYNAMIC Fa0/12
44 0001.427b.35a0 DYNAMIC Fa0/9
44 0001.c9e5.be01 DYNAMIC Fa0/3
44 000b.bec0.28a5 DYNAMIC Fa0/8
44 0090.2bac.1a6c DYNAMIC Fa0/9
44 00d0.5811.3aac DYNAMIC Fa0/4
44 00d0.ba9c.db07 DYNAMIC Fa0/9
44 00e0.a322.5848 DYNAMIC Fa0/9
44 00e0.a3ea.dd9b DYNAMIC Fa0/9
99 00d0.ba9c.db07 DYNAMIC Fa0/9
~由于目的地址不在mac表中，所以转发端口泛洪，转发端口9a1b Fa0/6处于vlan 33中
~~ vlan 33下端口 1 3 6 12？？？？
2）Vlan33中的端口
sw-ac3#show vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa0/16
22 servers active
33 Management active Fa0/1, Fa0/2, Fa0/5, Fa0/6
Fa0/7
~~1 2 5 6 7 ？？？？和mac地址表中的对应关系？？
3）查看处于Trunk口的端口
sw-ac3#show interfaces trunk 》》》》》》》注意不是 show ip interfaces trunk没有ip！！
Port Mode Encapsulation Status Native vlan
Fa0/3 on 802.1q trunking 1
Fa0/9 on 802.1q trunking 1
Fa0/12 on 802.1q trunking 1
4）查找出处于block状态的端口 # show spanning-tree vlan 33！牢记！
sw-ac3#show spanning-tree vlan 33
VLAN0033
Spanning tree enabled protocol ieee
Root ID Priority 24609
Address 00D0.9746.1686
Cost 19
Port 12(FastEthernet0/12)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32801 (priority 32768 sys-id-ext 33)
Address 00E0.F768.81B1
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 20
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/1 Desg FWD 19 128.1 P2p
Fa0/3 Desg FWD 19 128.3 P2p
Fa0/6 Desg FWD 19 128.6 P2p
Fa0/9 Altn BLK 19 128.9 P2p
Fa0/12 Root FWD 19 128.12 P2p
发现Fa0/9处于block状态。
9、用目的ip查找目的mac：
找出 SW-AC3向 190.0.2.5 发送信息的 目的mac地址
思路：目的ip不在本地vlan内时，信息首先被发往网关，所以便是查找网关的问题。SW-AC3上主机网关的路由器都是Vlan-R1。
1）确定Vlan-R1连接SW-AC3的端口 # show cdp neighbors 获取、发现相邻设备的型号。
sw-ac3#show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
vlan-r1 Fas 0/3 124 R C2800 Fas 0/0
vlan-r1 Fas 0/3 124 R C2800 Fas 0/0.1
vlan-r1 Fas 0/3 124 R C2800 Fas 0/0.22
sw-ds1 Fas 0/12 124 S 2960 Fas 0/3
vlan-r1 Fas 0/3 124 R C2800 Fas 0/0.33
vlan-r1 Fas 0/3 124 R C2800 Fas 0/0.44
sw-ac2 Fas 0/9 123 S 2960 Fas 0/7
》》》》》》》Vlan R1的本地端为Fas0/3
2）Local Intrfrce信息为Fas0/3 ，此时 需结合MAC地址表查找~最终结果如下：
sw-ac3#show mac
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
1 0001.c9e5.be01 DYNAMIC Fa0/3
Tips:
ctrl+U: 删除一行 ~~
ctrl+a:将光标移到首位 ctrl+e:移到末尾
ctal+z:退出配置模式，返回到EXEC模式。
Reference:
1) CDP cisco专用协议，可用于获取相邻设备上的硬件和协议信息。这些信息可用于排除故障和记录网络信息。
2) Port ID：对端设备上接口。我们所看到的内容都是与我们直接相连设备的。
3) Platform：直接相邻设备的类型。
4) show cdp entry *的 两个专项命令：
a)sw-ac3#show cdp entry * Protocol
仅可显示每个直连设备的 IP地址
b)sw-ac3#show cdp entry * version
可给出每个直连设备上运行的 IOS版本信息
Keyword:
VLAN Trunking Protocol | VLAN中继协议 | 虚拟局域网干道协议
