C3850 unable to logon after downgrading IOS from 16.12.03a.SPA.bin to 16.09.06.SPA.bin

[pdmarshall]

Good evening

help is need please

I lab tested this downgrade on a few 3850s single and in a stack of 2, and I've had no issues.

But doing it live tonight, I have 2 single switches and a stack of 2 that I have now lost logon onto.

I can ssh to it, but it is not taking the password.

I can't find this as a bug, and previously when upgrading there has never been an issue, just downgrading the IOS to the latest Golden image.

I am guessing I can console into them and reset privilege, but I have 30 to do, which will take longer to get to the remote sites than doing the upgrade.

I MD5 checksumed them before hand and got the correct match

verify /md5 flash:cat3k_caa-universalk9.16.09.06.SPA.bin

..Done!
verify /md5 (flash:cat3k_caa-universalk9.16.09.06.SPA.bin) = 710e1bbaa07b0c8f593af3cab9b5c385

These are not under support so no TAC.

Has anyone got any ideas?

Thanks

Phil

[Reza Sharifi]

Hi,

Can you try telnet and see if it works? Sometimes, after an upgrade, you have to reconfigure SSH.

HTH

[pdmarshall]

Hi Reza

Thanks for replying, sorry to say that I did try that before and it was connection refused.

Thanks

Phil

[Reza Sharifi]

Hi Phil,

If neither telnet nor SSH works, I am afraid, the only way to get to the device is now by using a console cable.

HTH