Show Vlan doesn't show my vlans. Just installed 720 blade in a 6513.

[bruce.porter]

I installed a new 720 sup blade. I then brought the Config back into the unit. I now show no vlans when I do a show vlan command.

This is the VTP domain server. Did I forget to back something up? Is it something that Cisco Works may have backed up in the past?

Please help.. Router is crippled without the vlans. thx

[jeremiah.peterson]

Did you back up your vlan.dat ?

[bruce.porter]

Thanks. I had missed that. There was also an issue copying the vlan.dat into the 720 supervisor... permissions on the vlan.dat on the new blade were set to -rw-. This wouldn't allow an overwrite or delete. Cisco had same issue and is working it. Thanks again.

[jcoke]

If the old switch is still available you can toggle VTP transparent mode on and the vlan config will show up in the running config. Copy it off and then paste it into your new switch.

[bruce.porter]

That should have worked but it didn't because of the bug in 12.2(33) that apparently prevents you from doing anything to the vlan.dat file at all.

I have been researching IOS versions and see something unusual about the 720 images.

If you go to the software download center and look for images for IP services, you see versions 12.2(18)SXF in the listing followed, right after, by the next higher version of 12.2(33)SXH.

If you go to the image compare tool and compare a 12.2(18)SXF image to a 12.2(33)SXH image, with the same feature sets, many of the features in the later version are not showing up, features, such as IPv6, HSRP and CDPv2, etc.

I am wondering is there an issue with images in the 720? Maybe it is just an issue with the IOS version-comparison tool itself.

[bruce.porter]

I was able to use a work around to get the vlan.dat file into the const_nvram: directory. At first I couldn't overwrite or change the vlan.dat file that was there on the blade as shipped.

The problem was solved by loading an IOS several revs back. It had SXF7 at the end of the name (12.2.18-SXF7) (despite all the warnings not to use this version because of flaws).

That version let me overwrite the vlan.dat. After that, I upreved to the version I needed and all was well.

NOTES:

I wasn't able to boot off the flash card (something about a magic number?). I suspect that either the flash card must be reformatted or the rommon upgraded.

There is a great deal of space in the bootflash though, which is called sup-bootdisk: in the IOS and bootdisk: in rommon>.

Make sure you keep a pristine copy of your startup-config somewhere on the system. The constant copy run stars with different versions of the IOS wreck havock with the startup-configs.

[Edison Ortiz · Accepted solution]

The best way to back up Vlan information while moving between hardware (like in your situation) is changing the VTP mode from "Server" to "Transparent".

In "Transparent" mode, the Vlan information is displayed in the running-config and such information can be captured along with the regular configuration.

Once you move to the new hardware, you can change back to VTP "Server" and a new vlan.dat will be created.

The only caveat is the revision number will be set back to 0, something to be aware if you are running multiple switches in your environment. Though, if you are running multiple switches in your environment, the Vlan information can be obtained from those switches after a hardware swap - no need to backup the Vlan.dat at all.

HTH,

__

Edison.

[jlunsford · Accepted solution]

The easiest way I find to do this is to pick one of your VTP clients and set it to server. Then bring your real VTP server back on-line as a client. It will learn all the VLAN info from the temporary server, and then when it is done you can switch it back to server and the other one back to client..

[bruce.porter]

You guys are good. thx