Strangely I was getting very mangled/broken output this morning on the console of an F5 appliance, and all baud settings etc were correct. Very confusing:
CIFLT1uabnm gn ay 1 221 CIFLT1 mg sysmhk 1d17 suppy #2 mas C npu v mvag 2) s ay 1 221 CIFLT1 mg sysmhk 1d1 suppy #2 an1 an spd ) s ay 1 221 CIFLT1 mg sysmhk 1d17 suppy #2 mas sandby v mvag ) s ay 1 221 CIFLT1 mg
Solution: full_box_reboot did the trick – this was a device in the process of being built but in case of production you could use the AOM to reset the console (ssh aom) in v11.x.
If you get stuck in the AOM prompt:
Press Enter to deactivate another concurrent session...
Get out with ~.