VTP domains allow you to manage all of your vlans from a central switch. This can be a great tool if you are dealing with a large number of vlans spread out over multiple switches. There are a couple of issues that you must be careful of when you implement a vtp domain, which I will go over shortly.
The first requirement is to make sure that your trunks between switches are up and working.
The first requirement is to make sure that your trunks between switches are up and working.
C3750-Payment#show interface trunk
And the output should look something like:
C3750-Payment#sh int trunk
Port Mode Encapsulation Status Native vlan
Fa2/0/48 on 802.1q trunking 1
Port Vlans allowed on trunk
Fa2/0/48 1-4094
Port Vlans allowed and active in management domain
Fa2/0/48 1-2,4,6,8,10,12,16-37,102-103,256-258
Port Vlans in spanning tree forwarding state and not pruned
Fa2/0/48 1-2,4,6,8,10,12,16-37,102-103,256-258
If there are not any ports listed as a trunk, that needs to be fixed before proceeding. Now that we know the switches are communicating, we can proceed to look at the current vtp configuration.
C3750-Payment#show vtp status
And you should get:
C3750-Payment#sh vtp status
VTP Version : 2
Configuration Revision : 0
Maximum VLANs supported locally : 1005
Number of existing VLANs : 7
VTP Operating Mode : Transparent
VTP Domain Name :
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0×18 0×17 0xE9 0×22 0×49 0×96 0×0C 0×7E
Configuration last modified by 10.10.10.20 at 3-1-93 00:03:25
If the VTP Operating Mode is not “Transparent” on all of the switches, it needs to be set to transparent to prevent problems later.
C3750-Payment(config)#vpt mode transparent
This will reset the Configuration Revision to 0. It is very important that all switches have the configuration revision reset!
Now, on the switch that you want to be the vtp server; set the domain, password, and then change it to server mode.
C3750-Payment(config)#vtp domain Test
VTP domain Test modified
C3750-Payment(config)#vtp password Testpassword
C3750-Payment(config)#vtp mode server
Setting the device to VTP SERVER mode
Make sure all of the vlans that you need are on this switch. Once they are, setup the other switches as clients.
C3750-Client(config)#vtp domain Test
Changing VTP domain name from NULL to Test
C3750-Client(config)#vtp password Testpassword
C3750-Client(config)#vtp mode client
Setting device to VTP CLIENT mode
Check the VTP status on the client to confirm the vtp status has changed and the vlans have been configured.
C3750-Client#show vtp status
VTP Version : 2
Configuration Revision : 62
Maximum VLANs supported locally : 1005
Number of existing VLANs : 38
VTP Operating Mode : Client
VTP Domain Name : Test
VTP Pruning Mode : Enabled
VTP V2 Mode : Enabled
VTP Traps Generation : Disabled
MD5 digest : 0xCD 0×9D 0xFF 0xC3 0×6F 0×63 0×5F 0xF5
Configuration last modified by 10.10.10.2 at 10-16-07 22:16:43
C3750-Client#show vlan
Everything is now configured. Vlan additions can now be made on the switch that is in server mode and they will be propagated down to all of the clients.
Adding a switch to an already established vtp domain is basically the same, just make sure to set the switch to transparent mode first. For more details, check Adding a Cisco switch to a vtp domain.