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New Member

VTP Issue

Our Organization have 20 Cisco access switches (3560 and 2950 models) and it's all are connected to 6509 Coreswitch with no redundancy. All switches are running VTP mode as a server without any domain. My question is If I add a domain name in VTP server which is running in Core 6509, then all other access switches(also running VTP server mode) drop the connection or not?

Please advice..


Re: VTP Issue


I think they will not drop the connection.If they are going to learn the VTP domain name they are going to become the members of that domain.

Some experts need to put more input.



New Member

Re: VTP Issue

Hi Mahmoud,

Can you please confirm that. Because We didn't get any downtime for the change management.


Re: VTP Issue


There would not be any downtime. The access switches will not drop the connection due to this.

you may have to configure the domain name in all switches as i have seen sometimes the VTP domain name is not learnt and the swithces does not change from null domain

HTH, rate if it does


New Member

Re: VTP Issue

Ideally shouldn't the access switches have the domain info entered, and then the mode switched to client?

Re: VTP Issue


To avoid or minimize the chances of any disruption of service configure all the switches to VTP transparent mode, configure the core switch & other switches (as you desire) with the VTP domain name and convert them to VTP server/client mode one-by-one starting from the core switch.



Re: VTP Issue

There won't be downtime from just changing VTP domain name. But start your migration by putting them in transparent mode first, then change domain name, then return client switches to the client mode, finally return server switches to the server mode. Ensure that nobody modifies VLAN database on any switch during the migration.

New Member

Re: VTP Issue


A small piece of advise, I would suggest that you limit the number of switches that are VTP Servers. I would suggest that you set the 6509 as the VTP server and all of the access switches to VTP client. This configuration will limit vlan changes to the core device and limit the chance of a change to your vlan settings.

As for your change, start with the Access switches. First set the VTP mode to client, then change the VTP Domain. Once you complete the changes to the Access switches make the VTP Domain change to the 6509 Core switch as it will be left as the VTP Server. Then to confirm create a test vlan on the VTP Server and ensure that the VTP Clients receive the update. Once confirmed remove the test vlan.

Hope the info helps.

Greg P

Re: VTP Issue

Hi gopal,I would request you to start with with access switch by converting them to client mode,one by one in this manner you will be left with 6509 switch as vtp server.In this manner your management will be reduced.

New Member

Re: VTP Issue

watch your revision numbers on the access layer switches...all it takes is one of them to have the same or higher revision number and then you will have issues... even in client mode. At least that is what I have always been told...

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