Transparent firewall works on layer 2 and not considered as hop. It often calls as bump in the wire. It deals with mac lookup and forwarding is done through destination mac address. It’s outside and inside interface exists in the same network. We can induct a transparent firewall easily into an existing network because of its layer 2 characteristic.
Some of the features of transparent firewall
- Each interface is a broadcast domain.
- ASA performing secure transparent bridging between two broadcast domains in form of VLA
- No routing protocol to troubleshoot
- In common mode is going to see route lookup. In transparent mode it going to see media access lookup.
- It supports – mac application talk, IPX traffic, MPLS traffic, BPDU traffic,
- ARP inspection (most popular transparent inspection)