I’m trying to see if it is possible to introduce two transparent ASA 5520s in an Active/Standby pair between 2 switches that don't currently run any form of STP.
Does anyone know if this is a supported configuration? I’m aware that if both ASA units thought that they were the master this could introduce a L2 loop but under normal operation would a failover succeed without creating a loop or is STP definitely required to achieve this set-up?
I'm trying to avoid having to use routed mode in this instance as re-numbering the address spaces would be quite difficult for this particular scenario.
Exactly, while one unit is on standby mode it will not introduce any loop as it will not be forwarding any data.
That being said it's a supported scenario