Firewall Types

There are two major types of firewalls. The first is the packet aware packet filter. The second is the session aware application level gateway.

The packet aware firewall is aware of packets only and has no concept of a session. Each packet that passes through it is processed without regard to the packets that come before or after it.

The application level gateway has full knowledge of sessions and the applications that create them. It processes packets fully aware of which session each packet is associated with.