I would like to know how do the Cisco network devices as well as FWSM communicate with different VLANs defined on Cat6500 24/48 port switch. Is SVI required for every VLAN defined on Cat6500 switch ?
For e.g. if an ASA is connected to VLAN2 (192.168.1.x subnet) on Cat6500 switch and would like to initiate connection to FWSM which is connected to VLAN3 (192.168.2.x subnet).
You would need an SVI for both vlans to route traffic between those vlans. So yes an SVI is required for both vlan 1 and 2 in your example.