I have two 6500s (primary/secondary w/ HSRP) and one IDSM. I want the IDSM to monitor the inside interface of two firewalls (active/standby). One firewall inside interface connects to one 6500 and the other firewall to the other 6500. The firewalls and 6500s are apart of a small network and VLAN (100). How do I get the one IDSM to monitor the traffic from the inside interfaces of the firewalls? My concern is if the firewalls failover the IDSM could potentially stop seeing network traffic. For example, if I have the IDSM monitor the primary firewall port. Traffic is lost when the firewall fails. Similarly, if the IDSM (6500A) is monitoring the VLAN 100 and the firewall connected to 6500B is active. I believe traffic could enter and leave 6500B without ever being forwarded to 6500A and monitored by the IDSM.

Thoughts?