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Webcast-Catalyst9k
New Member

best practices for VTP / VLAN environment

Hi,

We currently have 1 VTP domain where all our network devices are configured.

We now want to join another VTP domain to this domain and I wander what the best approach will be to do this.

1. I can configure all the VLAN ID's at my own VTP server ( there are no overlapping ID's ) and configure the devices from the other domain as clients ( but what happens to the VLAN configurations made on the old VTP server ? ).

2. connect our 2 networks

or is it better to change only the VTP domain on the other VTP server ( the same as ours now ) and then connect the networks together ( what will happen with the VTP/vlan configuration of both servers, will they be added or will the sever with the highest revision number just copy his database to the other server and probably delete the current VTP/VLAN configuration ?

Is is good to have 2 VTP servers ?

7 REPLIES
Silver

Re: best practices for VTP / VLAN environment

If migration VTP servers in one network first:

Make sure your VLAN do not overlap..You did that.

Determine which VTP server you do not want to be in control.

Make the one you will get rid of th VTP client with the same VTP domain name.

The current VTP server will overwrite the vlan from the server to the client. Since the VLAN overlap no new vlans will be created or deleted.

Once you are in VLAN sync, you can make a 2nd VTP server, because the revision numbers will be in sync, just keep in mind that now there will be two points where VLAN's can be made/deleted/modified...

New Member

Re: best practices for VTP / VLAN environment

I would like to warn you!

As soon as the VTP server you want to get rid of will be moved in the other domain, its config revision number will be 0 (The change of domain name will reset the config revision number). Its vlan database will be erased by the VTP server of the new domain. All the vlans of the old VTP domain will be lost.

I would proceed in this way (VTP A is the VTP you want to keep, VTP B is the VTP you want to merge into VTP A):

1) configure all the VLANs of VTP B in VTP A

2) reconfigure all VTP B's switches as VTP A client.

That's it.

Regards,

Christophe

New Member

Re: best practices for VTP / VLAN environment

What will happen with the VLAN of the other domain, you said they wont be deleted but will the server update his database with these records or not ?

What will happen with the VLANs itself on that server since they are configured ( L3 switch which acts as default gateway for all those VLANs )

New Member

Re: best practices for VTP / VLAN environment

As long as you have configured every vlans of VTP B into VTP A, when you will change the domain name of one VTP B's switch, this switch will replace its vlan database by the VTP A's vlan database. Since you have configured all VTP B's vlan in VTP A you wont loose any vlans.

The vlan interfaces on the L3 device won't noticed the VTP change.

I hope this helps you.

Regards,

Christophe

Please rate if it helps. :-)

New Member

Re: best practices for VTP / VLAN environment

Having two VTP servers is not a problem at all. You will just have two switches on which you can add/remove vlans from the VTP domain.

I have a customer who configure all the distribution switches as VTP server (usually 4 per VTP domain) and he hasn't had any problem for several years.

Regards,

Christophe

New Member

Re: best practices for VTP / VLAN environment

I'll rate the messages as soon as I will merge the VTP domains.

I will be doing this somewhere at the end of this month.

I was thinking in the same way as Lemaire but wanted to be sure that it was the BEST way to merge them.

New Member

Re: best practices for VTP / VLAN environment

I've done the migration but had 1 problem.

When I configured the new servers and configured the old VTP domain to match our VTP domain no updates were send ( client or server mode )

No updates were send after shutting down and enabling the interface or runk or even after a reboot.

I had to delete the vlan.dat file in flash to make it all work.

From my previous expierence I know that this isn't the normal procedure to follow.

Why did the updates work fine after deleting the vlan.dat file ?

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