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New Member

Switch VTP domain?

I need some advice with VTP domains:

I have two remotes sites with Cisco Catalyst 3524XL switches. SiteA has 3 switches and SiteB has 2 switches. Each Site is it's own VTP domain, and seperate subnet. Someone will move 1 switch (VTP Client) from SiteA and install it at SiteB. The switch is currently network connected through the GBIC port(so I can telnet to it) but no ports are in use, so losing connectivity when I change the IP address to SiteB isn't a problem.

Here is the Problem: The person doing the physical move will not have access to the switch configurations to change settings, so I need to make all changes via telnet, if possible. I will change the IP address before it is disconnected from SiteA. But what should I do about changing the VTP domain name from SiteA to SiteB? I am concerned about messing things up at SiteB with the VTP revision #. Should I change the VTP domain on the switch before it is disconnected from SiteA or after it is reconnected at SiteB? Do I need to do anything else, like reset the revision # on the switch so that it doesn't overwrite the VTP database of the existing SiteB switches?

Any advice is appreciated. Normally, I would just reconfigure the switch from scratch, but I would like to do the changes remotely if I can.



New Member

Re: Switch VTP domain?

If it were me, my first choice would be to send a preconfigured one to Site B and have the person send Site A's to you. Evidentally you can't do that. My next choice would be to build a new config and copy it to the switch using COPY TFTP START right before disconnecting it from Site A, so that the next startup would use Site B's config. Another way to go is to reconfig the switch disabling VTP while at Site A, and then reenable VTP after the move to Site B.

Of course the hitch to all of that is what to do if something goes wrong and you can't telnet back to it. do you have enough equipment at your office to set up a test to try different ways and see which way you like best?

However, if the VTP domain names are different, I don't think they will even know about each other. Could someone else tell us about that? Seems the best way to know that is if you actually did it (even if it was by mistake!)

Re: Switch VTP domain?

Jim is right, copy tftp start is the safe way to handle IP address changes and even more complicated configuration changes. But it doesn't fix the VTP problem - VTP info is not saved in the config file. But changing VTP domain should set VTP configuration revision number to 0 on your switch, so there should be no harm. What I would do is: disconnect all users from the switch, then copy a new config to startup configuration, change VTP domain name and switch off the device. After moving to new site the switch should boot with new config, correct VTP domain name and VTP revision 0 - everybody happy.

This is how it should work - if everything works correctly.



New Member

Re: Switch VTP domain?

Thanks for the advice. Those are some good ideas.