Does anyone have any experience with using the same interface for LAN and stateful failover? Cisco documentation suggests using two interfaces. I am about to convert from a PIX 525 to an ASA (deciding on model). I would prefer to not burn 2 of the 4 GiE interfaces on failover. Currently my PIX 525 uses a serial cable and a 100 Mb interface. The stateful interface is passing about 10 Mb /sec of traffic. The serial cable is rated at 115K. These numbers would suggest 1 GiE interface would be plenty.
You can use one interface for both if you wish. This is in fact how I setup my ASA's. Here is some documentation to help you: