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New Member

VTP question

I am confused about VTP, and I'm sure someone here can clear up my confusion.

Currently, most of our closet switches are set as VTP clients getting VLAN updates from our core switches (6500's). When I do a "show vlan" on the closet switch it will show the entire list of vlans that have been created on the core, which is what I would suspect. Now, on a couple of our closet switches we have enabled prunning on the core to only send the necesary vlans to that switch. Doing a show vlan proves that it works. When I change the closet switch to vtp transparent, the vlans still show up when a show vlan is requested. Also, I recently added a vlan to the 6500's that I wanted propagted to the closet switches, thinking that the transparent mode switches would not recieve that vlan update, but they did. So, basically I am looking for an explanation of why transparent mode would update it's vlan database from a root switch. Isn't it true that a transparent switch will only add locally created vlans and ignore all other vtp updates? ANy help is appreciated.

3 REPLIES
New Member

Re: VTP question

Have you verified that the transparent switches are configured correctly? A transparent switch does not ignore vtp updates they will forward vtp advertisements out any configured trunk ports but they should not update their database.

New Member

Re: VTP question

Also for a transparent switch to forward vtp advertisements it must be running vtp version 2.

Re: VTP question

Hi,

what hw/sw are the closet switches?

Are you 100% sure they are running in VTP transparent mode?

What is the sh vtp status (sh vtp domain for CatOS) output?

Have you tried to reboot one of them?

I'd also try to find a VTP bug for the sw image using CCO Bug Toolkit.

Regards,

Milan

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