Here is the scenario,
We have 2x ASA 5520's in an HA pair (Active/Standby), we need to connect the outside interfaces to two other ASA 5520 also in an HA pair (Active/Standby).
My question is can the outside interfaces from the first pair of ASA's be connected directly to the outside interfaces of the other ASA, or do the outside interfaces of each local pair need to be able to talk to one another?
outside interfaces on the ASA need to poll each other in active/standby failover pair to be sure that they are up and running. if you connect them directly to another pair of the ASA outside interfaces they wont be able to talk to each other.
you should have a switch in between the ASA pairs that will make it work.