Best Practise for VTP Transparent?

[andrew.butterworth]

When I configure Cisco switches unless there is a specific reason to use VTP (legacy network) I would normally configure VTP Transparent (or if its a recent CatOS switch disable VTP). I understand Server, Client & Transparent concepts but was wondering about the VTP Domain Name when using Transparent mode.

I would normally configure VTP Transparent before anything else on the switch but don't configure a VTP Domain Name:

cat-2950#sho vtp status

VTP Version : 2

Configuration Revision : 0

Maximum VLANs supported locally : 250

Number of existing VLANs : 8

VTP Operating Mode : Transparent

VTP Domain Name :

VTP Pruning Mode : Disabled

VTP V2 Mode : Disabled

VTP Traps Generation : Disabled

MD5 digest : 0x73 0xC8 0xF8 0x2C 0xB1 0x67 0xB6 0xC4

Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00

Are there any issues with not configuring a VTP Domain Name?

Andy

[glen.grant]

Will it let you create vlans without a domain name ? For some reason it seemed like you had to have a domain name even in transparent to create a vlan at least on catos , not sure about IOS . We just put one in anyway . If not then there should not be any issues that I can think of .

[Roberto Salazar]

Waht kind of issue are referring to? VTP transparent as you know would not send VTP, so not having a domain name would be okay since no VTP is sent from this switch anyway. As for creating a vlan on a VTP transparent, you should and will be able to do that as well. And from the sho vtp stat, it looks like you've already created 3 new vlans as it should have 5 vlans by default. I can't think if any issues.

[andrew.butterworth]

Yes you can create VLAN's without a VTP domain name and in Transparent mode, or at least on Catalyst IOS you can.

The issue I was thinking of was when you take a vanilla switch and connect it to an existing switch with a trunk and the new switch inheriting the VTP domain name and vlan database. For example if I configure up a 2950 as a VTP server with a domain name of VTP and then create VLAN's 10, 20 & 30. If I then take an unconfigured 2950 (or one that has had the configuration erased and the vlan.dat file removed) and put a cross-over cable between them, an 802.1q trunk link will be formed and the 'new' 2950 will inherit the VTP domain name VTP and the vlan database containing VLAN 10, 20 & 30.

Will the VTP domain name be inherited if the switch was set to Transparent before it was connected?

Andy