I have a problem with ASA5506X version 9.5.2. Active/Standby falover is configured but it seems that the outside interface status is not monitored correctly.
Failure of the inside interface activate the standby normaly, but a failure of the outside interface link does nothing. Even more. On the serial console of the "active" ASA5506, the show interface GigabitEthernet1/1 show the interface as "up" even tough there is no network cable connected to it.
So it's probably why the failover is not activated by failure of the outside interface
a "show failover" also reports the outside interface as normal even though no network cable is connected to it
If the failover is forced from the "secondary" now active, seems like both becomes active and no traffic id forwarded. A reboot of the secondary unit, brings back communication as it returned to it's standby state. I have done these setup many times with the ASA5505 without any problems.
Error message at boot process saying "Failed to start admin listener" Can't say it's related to the problem but I think it's very likely
