Can VLAN traffic pass through an ASA?
Let's say I had the topology L3Switch1 -> ASA -> L3Switch2
Is it possible for the ASA to pass VLAN information to L3Switch2?
Example Setup
Solution 1:
If you configure the interfaces on the Cisco ASA as trunk interfaces and tag the traffic coming from the switch, it can pass along the tags assuming your Cisco ASA has been configured in transparent mode.
With regards to your comment, a transparent firewall is as secure as a firewall in routed mode. Both can check L3/L4 traffic.