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Purple

vlan.dat file

Does anyone back these up on their tftp server?Has anyone ever run into the problem where if you lose a supervisor and you have to replace it and you only replace the config without replacing the vlan.dat file it wouldn't comeup ? I would think you would have a vulnerability there . Not sure why they couldn't just put everything into the config instead of having a separate file for the vlan info . would like to hear how everyone else handles there switches and backing up this file.

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New Member

Re: vlan.dat file

The vlan.dat file is a major thorn to backing up switch configs. The main problem is that it is a binary encoded file, and there are no decoders that I know of.

Yes, you could use tftp or CiscoWorks to back it up. However, if you have a switch failure and you need to restore it, its not easy. You have to get basic config and probably some vlan info on the switch to get to the point where you could reload it. Or play with swapping flash cards around, if the switch supports it. And you really have no idea whats in the file and if its correct even if you can load it.

There are basically two ways to recover from a missing vlan.dat file. The first is to use a VTP domain. When a replacement switch is installed, it will hear the VTP broadcast and configure itself.

The second is to use VTP transparent mode. In transparent mode, all of the vlan config is written to the main config file, where it can be pasted in just like any other config.

I like either method over trying to reload the raw vlan.dat file.

Greg

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