Warning: Attempting to overwrite an NVRAM configuration previously written by a different version of the system image

[lcaruso]

Hi,

I upgraded the IOS on my 887VA router which is not yet in service. The next day I did a cold boot and made some changes. Then, when I wrote them this warning popped up which seems to imply I need to recreate my configuration from scratch in order to avoid potential issues

Is that the correct interpretation of this message/scenario?

router#wr
Warning: Attempting to overwrite an NVRAM configuration previously written
by a different version of the system image.
Overwrite the previous NVRAM configuration?[confirm]
Building configuration...
[OK]

[Peter Paluch · Accepted solution]

Hello,

That message is simply telling you that your current IOS version is different from the one that saved the startup-config into the NVRAM. You current configuration will be saved to the NVRAM in its current form, and it will be loaded correctly if you reload the router with the same version IOS as you are running right now. However, if you boot the router using the previous IOS version, the configuration may not get loaded correctly because of obvious reasons - slight syntax changes, new commands that are not yet supported in the previous IOS version, etc.

So if you are not going back to your previous IOS version, you can safely ignore this message.

Best regards,

Peter

[lcaruso]

Thanks much.