we have a client who has switches all over the place. One of the switch is in VTP client mode, and I am trying to find out who its VTP server is. there are multiple VTP servers in the network though.
Issue the following command:
show vtp status
you should see something like this:
Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00
The IP address you see will be one of the VTP servers. I don't know of any way to show all the VTP domain servers at once.