Hey guys,
I just experienced this myself. I was upgrading a WS-C2960X-48FPS-L from 15.0(2)EX4 to 15.2(4)EX6. My switch would hang on:
POST: ACT2 Authentication : Begin
POST: ACT2 Authentication : End, Status Passed
extracting front_end/front_end_ucode_info (43 bytes)
and it would just stay there. I pulled the power cable and nothing . Issue was apparently still there. I called Cisco TAC and with them on the phone I pulled the power cable again and this patiently waited. Switch came up and already running on the new version. My suggestion is if you run into the same issue, pull the power cable and just wait. If it gets passed the lines referenced above, you should be good to rock. Hope this helps anyone out there.
manny
