Cisco switch starting-config changing after switch boots

angelajackson94 · ‎08-24-2021

Good morning all, I have a Cisco switch that is displaying some strange behavior. I have a .cfg file that I am copying to starting-config, and I verify it looks correct when i do show starting-config. However, when i reload the switch, the running-config is slightly different from the starting-config. After reload, the running-config (which I assume should be identical to what I made the starting-config) has a couple of VLAN and ports with slightly different IP addresses than the .cfg file that I set to the starting-config. I'm not sure why the running-config for the switch is not using the exact contents of the .cfg file I was setting as the starting-config. Is there anything that might prevent it from using the .cfg file I selected, or anything that might be changing it?

Leo Laohoo · ‎08-24-2021

Was the VLAN.dat deleted before the reload?

angelajackson94 · ‎08-24-2021

Hi Leo, thanks for the quick reply. Yes, I deleted both vlan.dat and config.text prior to reload. Post reload, vlan.dat was the same size as the original, and config.text was the same size as my .cfg file that I copied to starting-config.

Leo Laohoo · ‎08-24-2021

Let me get the process correctly:

Delete the config (wr erase)
Delete the VLAN.dat
Reboot the switch
Copy the config to startup

Is this correct?

angelajackson94 · ‎08-24-2021

1. wr erase

2. delete vlan.dat

3. delete config.text

4. reboot

5. copy abc.cfg start

6. reboot

At this point, the switch boots with everything in abc.cfg as the starting-config, except a couple IP's for a VLAN have changed.

We actually just discovered it was happening on two of our switches. One of their VLAN IP addresses in the running config was getting swapped so switch A thought it was switch B and vice versa. The abc.config that we copy to start had them labeled correctly in both switches, but post reboot they seem to get mixed up somehow.

Leo Laohoo · ‎08-24-2021

@angelajackson94 wrote:

We actually just discovered it was happening on two of our switches. One of their VLAN IP addresses in the running config was getting swapped so switch A thought it was switch B and vice versa. The abc.config that we copy to start had them labeled correctly in both switches, but post reboot they seem to get mixed up somehow.

I have never seen this sort of behaviour before.

Is it the same if the config was copied into the running-config?

angelajackson94 · ‎08-24-2021

If we copy the .cfg into running-config, the switch has the correct IP. As soon as we reboot, however, the IP changes.

I wonder if maybe doing "copy run start" after we do "copy abc.cfg run" might change anything. I don't think it should be any different from just "copy abc.cfg start" after we delete our files and reboot, but the behavior is very strange like you mentioned so I think I'll give it a shot anyway.

Leo Laohoo · ‎08-24-2021

Another thing, try a different file extension, say, txt (instead of cfg).

angelajackson94 · ‎08-24-2021

Do you mean for the file I am copying to start? Use one with a .txt instead of .cfg?

Leo Laohoo · ‎08-24-2021

@angelajackson94 wrote:

Do you mean for the file I am copying to start? Use one with a .txt instead of .cfg?

Yes. Txt to start.
If it does not work, txt to run (and then save).

angelajackson94 · ‎08-24-2021

Got it. Thanks for the help Leo, ill give it a try... but what do you mean by "and then save" ?

edit: i think that means txt to run, then run to start. thank you again!

angelajackson94 · ‎08-24-2021

edit

mlund · ‎08-25-2021

Hi

I agree with Leo, this is really strange behavior. But just to clarify, you mention you are copy to starting-config, is this a typo? It should be startup-config. Because the switch is using startup-config, not starting-config when booting up.

/Mikael

angelajackson94 · ‎08-25-2021

Yes, that's a typo on my part. When I type the command I always just type start so I was a little hazy on the full phrasing