VLAN not present in running config.

[fariha zain]

Hi Experts,

I have my switch running in Transparent mode and I am trying to copy the configuration on to it.

The config got uploaded but VLAN information is missing. I would like to know the reason for the same?

As in transparent mode it should not be bothered about looking the vlan.dat file as the vlan information is saved on the vlan.dat and running config, hence when i have the copy of running config and applying the same now on this switch but the vlans are missing.

Any help.

Regards

Fariha

[Bilal Nawaz · Accepted solution]

Hello. If you are trying to copy from another switch then there may be a valid reason why the vlans didn't get copied across.

All of the vlan info is saved in the VLAN.dat file, normally located on the flash of the switch.

Transparent mode or not, this is the same for all switches.

Remember when we want to factory reset a switch, there are two stages. Write erase the config. And also erase the VLAN.dat file too, to erase all of the VLAN information.

This is because all of the vlans are created in this file. You can copy from flash: vlan.dat

http://www.cisco.com/en/US/products/hw/switches/ps607/products_tech_note09186a00800c4546.shtml

Hope this helps

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[fariha zain]

Hi Bilal,

Yes I understand that,  but the configuration copy is from the same switch, I have just replaced the Sup module and re-applied the config after which I dont see the vlan information.

Do you have any reason?

Regards

Fari

[InayathUlla Sharieff · Accepted solution]

Hi Fari,

I agree to what bilal said and it is the same answer from me.

Have a look at the link below:

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/20ew/configuration/guide/vlans.html

If the switch is in VTP server or transparent mode (see the "Configuring VTP" section on page 24-6), you can configure VLANs in global and VLAN configuration modes. When you configure VLANs in global and config-vlan configuration modes, the VLAN configuration is saved in the vlan.dat files, not the running-config or startup-config files. To display the VLAN configuration, enter the show vlan command.

If the switch is in VLAN transparent mode, use the copy running-config startup-config command to save the VLAN configuration to the startup-config file. After you save the running configuration as the startup configuration, the show running-config and show startup-config commands display the VLAN configuration.

HTH

Regards

Inayath

[fariha zain]

Hi both,

Yes I understand the concept but practically its not working as expected.

I have just removed the primary sup and inserted the new sup module and reapplyied the config.

Why did it not copied the vlan into the configuration thats my big concern?

Regards

Fari

[Bilal Nawaz]

Hello,

In order to perform a complete backup of your configuration, include the vlan.dat file in the backup along with the configuration. Then, if the entire switch or the Supervisor Engine module requires replacement, the network administrator must upload both of these files in order to restore the complete configuration:

The vlan.dat file
The configuration file
Reference:
http://www.cisco.com/en/US/products/hw/switches/ps5213/products_tech_note09186a0080a49dbf.shtml

Cisco also state that:

When the switch boots, if the VTP domain name and VTP mode in the startup-config and vlan.dat files do not match, the switch uses the configuration in the vlan.dat file.

Reference: http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/20ew/configuration/guide/vlans.html

In your case if there was already a vlan.dat file present then it would have ignored the configuration. Did you have the vlan in your startup-config file?

If so, this is likely to be the reason why. Hence why Cisco advise to backup both vlan.dat and config files.

Hope this helps

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