Thursday 4 February 2010

Configure VTP

In this post I will configure VTP. I will be working with Switch1 and Switch2. I will configure port fa0/9 on each switch as a trunk port, configure VTP for the domain lab.local with a VTP password of cisco. I will configure Switch2 to be a VTP Client. Finally I will verify VTP is working with some useful show and debugging commands.


Switch 1

switch1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
switch1(config)#int fastEthernet 0/9
switch1(config-if)#switchport mode trunk
switch1(config-if)#exit


switch1(config)#vtp domain lab.local
Changing VTP domain name from NULL to lab.local
switch1(config)#vtp password cisco
Setting device VLAN database password to cisco.
switch1(config)#end


switch1#sh vtp status
VTP Version : 2
Configuration Revision : 0
Maximum VLANs supported locally : 64
Number of existing VLANs : 6
VTP Operating Mode : Server
VTP Domain Name : lab.local
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0x12 0xBF 0xAA 0x37 0xDC 0x26 0xF2 0x03
Configuration last modified by 10.0.1.210 at 3-1-93 03:11:00
Local updater ID is 10.0.1.210 on interface Vl1 (lowest numbered VLAN interface found)


Switch2

switch2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
switch2(config)#interface fastEthernet 0/9
switch2(config-if)#switchport mode trunk
switch2(config-if)#exit

switch2(config)#vtp domain lab.local
Changing VTP domain name from NULL to lab.local
switch2(config)#vtp password cisco
Setting device VLAN database password to cisco
switch2(config)#vtp mode client
Setting device to VTP CLIENT mode.
switch2(config)#end


switch2#sh vtp status
VTP Version : 2
Configuration Revision : 0
Maximum VLANs supported locally : 64
Number of existing VLANs : 6
VTP Operating Mode : Client
VTP Domain Name : lab.local
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0x12 0xBF 0xAA 0x37 0xDC 0x26 0xF2 0x03
Configuration last modified by 10.0.1.210 at 3-1-93 03:11:00


Turn on debugging for VTP events on Switch2

switch2#terminal monitor
switch2#debug sw-vlan vtp events
vtp events debugging is on


Create a new VLAN on Switch1

switch1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
switch1(config)#vlan 3
switch1(config-vlan)#name test-vlan
switch1(config-vlan)#end


Switch2 displays the VTP events.

00:11:10: VTP LOG RUNTIME: Summary packet received, domain = lab.local, rev = 1, followers = 1

00:11:10: VTP LOG RUNTIME: Summary packet rev 1 greater than domain lab.local rev 0

00:11:10: VTP LOG RUNTIME: Domain lab.local currently not in updating state

00:11:10: VTP LOG RUNTIME: Subset packet received, domain = lab.local, rev = 1, seq = 1, length = 244

00:11:10: VTP LOG RUNTIME: Transmit vtp summary, domain lab.local, rev 1, followers 1
MD5 digest calculated = C5 62 5F 4A 7B 07 69 C7 0E CD E9 42 0E 7C AF 5C


I verify that the VTP revision number has incremented on switch2

switch2#sh vtp status
VTP Version : 2
Configuration Revision : 1
Maximum VLANs supported locally : 64
Number of existing VLANs : 7
VTP Operating Mode : Client
VTP Domain Name : lab.local
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0xC5 0x62 0x5F 0x4A 0x7B 0x07 0x69 0xC7
Configuration last modified by 10.0.1.210 at 3-1-93 00:20:13



Attempts to create a VLAN on switch2 fails as it is in Client mode

switch2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
switch2(config)#vlan 4
VTP VLAN configuration not allowed when device is in CLIENT mode.