I know this is an old thread, but in case someone finds this and would like an answer, the reason is in the output.
Stack topology is not a ring. ISSU upgrade aborted
Original Message:
Sent: Aug 26, 2024 04:30 PM
From: Evan Z
Subject: Tell if 'Allow unsafe upgrades' is required
Is there a command to display if a VSF pair of switches needs 'unsafe updates'?
I just upgraded from 10.13.1031 to 10.13.1040 on CX 6300s
It did not allow me to do an ISSU update. Is this a possible reason why?