Password required, but none set

on October 9th, 2015 by Hades | No Comments »

I had a strange thing happen today when I upgraded a 2960G/WS-C3750X-48T-S from IOS 12.2 to 15.0. After booting the upgraded IOS, I logged in, entered the enable command, and was surprised to get this error:

3750x-01>en

Password required, but none set
Password:
3750x-01#


Everything seemed to work fine, but it was a little odd. I did discover that the following command resolves the error:
aaa authentication enable default enable