How to recover VLAN's if they're all wiped out? Just asking...

[000node000]

Today, I added some switches to a large production network. I first put them in VTP transparent mode and on a dummy domain to avoid wiping out my VLAN's.

But what if the VLAN's were wiped out by a new switch with a higher revision number? Would restoring be difficult? Even if my servers had backups of vlan.dat, the revision number would be less than current bad configuration. I guess I could reset the revision # to all the switches to zero...

I read Cisco's website and it seems their only advice is to quickly recreate all VLAN's. No duh....

Tomorrow, I will do some testing on a couple of switches and report any surprises...

[Peter Paluch]

Hello,

Unfortunately, I do not know of any good way to quickly restore the VLAN definitions if the VTP database get erased by a misbehaving VTP switch.

What I am thinking about is having a textual configuration of all VLANs available somewhere. Perhaps having a switch join the VTP domain, then - after it synchronizes its VLAN database - convert it to VTP Transparent mode, capture the VLAN definitions from the running-config and convert it back to VTP Server/Client mode. This would allow you to always keep a textual copy of your VLAN database, and in cases of emergency, you could simply paste it in your configuration again.

It would actually be SO helpful if there was a utility that could decode the vlan.dat into a text representation compatible with the CLI so that it would be possible to keep a text copy of the VLAN definitions! Well, maybe I'll write one...

Best regards,

Peter