Thanks Leon,
Here is a snippit from the link you provided.
"This switch was previously used in the lab, and a good VTP domain name was entered. It was configured as a VTP client and was connected to the rest of the network. Then, the ISL link was brought up to the rest of the network. In just a few seconds, the whole network is down. What could have happened?
The configuration revision of the switch you inserted was higher than the configuration revision of the VTP domain. Therefore, your recently-introduced switch, with almost no configured VLANs, has erased all VLANs through the VTP domain.
This happens whether the switch is a VTP client or a VTP server. A VTP client can erase VLAN information on a VTP server. You can tell that this has happened when many of the ports in your network go into inactive state but continue to be assigned to a nonexistent VLAN."
This indicates that the configuration number is indeed stored somewhere and that this alone would make no sense unless it stored the vlan information for that revision number.
I have since run a test on my VTP client and a vlan.dat file is created and indeed reappears on boot up.
As far as I can see, Odom is wrong.
Regards,
Phil.
