I have read that a VTP client can synchronize a VTP server if the client Revision number is higher than the server.
If it is correct to assume that the only switch in a VTP domain to hold the VLAN database is the server, can we say that the VLAN information for a client is lost as soon as power down the switch. In that case, the only way I can see, this is probably where I am wrong, a client can update a server is if the switch has an higher revision number and is connected to a new VTP domain without being shut off.
Thanks for your help
the VLAN information for a client is NOT lost as soon as power down the switch. It's still available in the vlan.dat file.
for details of the "VTP bomb" well-known problem.