I have 2 ASA 5550's in active/standby configuration. The customer wants to put some sort of 3rd party monitoring device on the outside of the ASAs. They need to monitor both ASA's at the same time. Can the management interface be given a different address on either box.
ASA 1 192.168.1.1
ASA 2 192.168.1.2
We're running 7.1(2)72
The standby device is never used by the clients themselves. Whichever unit is 'Active' it starts replying to the 'Active' IP address and the 'Standby' unit takes over the 'Standby' IP Address. However you can telnet/snmp to either IP address. And this should fulfill your goal.
There are some caveats tough, e.g. if the Management Machine is reachable to the ASA via a dynamic routing protocol then the standby unit will not have those dynamic routes in its routing table. This will need some special workarounds. Other than that, you can connect to the standby unit anytime you want. However its not recommended/supported to make any changes on the standby unit. Monitoring is OK tough.