We're running redundant ACE SM's in two 6509's. Each ACE SM has 6 context and all them have the "no preempt" line, with ACE1 being active and ACE2 being the stand-by and they're in sync. Last night we upgraded the ACEs from the Version A2(2.4) to A2(3.2). We had to upgrade the active ACE1 first and then the standby ACE2. When the ACE1 was rebooted, the ACE2 became active and stayed this way because of the "no preempt" command, until it was rebooted as part of the upgrade . However, would it try syncing up the configs with ACE1 after ACE1 came back up?
