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New Member

VTP Question

Hi everyone! I have a quick question about managing multiple VTP domains.

First off, I have three VTP domains in my all cisco network. I know using VTP version 2 is not the most secure thing in the world, and best practice is to set them to transparent or use VTP Version 3...but for now I'm using this because it just makes it easier.

My question:

Is it possible for one VTP domain to have the same VLAN as another VTP domain? Reason I'm asking is, I have a data center VTP domain...I want a VLAN that appears in another one of my VTP domains to appear in this VTP domain, so I can assign it to ports and have it pass out addresses in that range. Let me know if I'm wording this strangely, or have the wrong idea!

1 ACCEPTED SOLUTION

Accepted Solutions
New Member

Re: VTP Question

Hi,

VTP is only "Advertising" protocol. If you need to have the same Vlan in 2 switches running different VTP domain, then you need to create the same Vlan on both VTP servers on both VTP domains. Just don't forget to allow the Vlan on trunks between the switches.

HTH,

BR,

Timor Sherf

6 REPLIES
New Member

Re: VTP Question

Hi Cinmachina,

Let me try this one.

First of all, i would say, why you would require two different domain when you are having same VLAN info in both the domain? If at all its your requirement, then from my point of you, it is not possible to have such scenario, VTP server shares vlan info based on the domain name it is configured with. VTP client will synchronise it with the VTP server having same domain name.

Any one please correct me if at all i'm wrong with this concept.


Regards,

Hardik

New Member

Re: VTP Question

There are over 50 VLANS in each one of the VTP domains. I just want a SINGLE VLAN to be shared.

Purple

Re: VTP Question

   Don't see why you couldn't.

If  you connect a port on one switch with say it assigned to vlan 3 to another switch in a different

vtp domain in vlan 3  it is going to talk ok .  If you connect the two different domains together  with a trunk just make sure it is a transparent trunk and only allow whats needed  across the  trunk .   This is all assuming those vlans are in the same ip address range , you can't obviously have a vlan 3 say 192.168.3.0/24  in one vtp domain  and connect it to a vlan 3 in another vtp domain that is say 192.168.10.0/24  .

New Member

Re: VTP Question

Hi,

VTP is only "Advertising" protocol. If you need to have the same Vlan in 2 switches running different VTP domain, then you need to create the same Vlan on both VTP servers on both VTP domains. Just don't forget to allow the Vlan on trunks between the switches.

HTH,

BR,

Timor Sherf

Cisco Employee

Re: VTP Question

You might need to turn off CDP on the trunk ports also, I believe you will receive annoying message about VTP domain name mismatch.

Regards,

jerry

New Member

Re: VTP Question

Yes you can, VTP is used only to advertise Vlan information,

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