Firewall Components

The primary components (or aspects) of a firewall are:

• network policy,

• advanced authentication mechanisms,

• packet filtering, and

• application gateways.

The following sections describe each of these components more fully.

• Network Policy
• Service Access Policy
• Firewall Design Policy
• Advanced Authentication
• Packet Filtering
• Which Protocols to Filter
• Problems with Packet Filtering Routers
• Application Gateways
• Circuit-Level Gateways