This section discusses some of the basic features of the PIX Firewall. These features are the fundamental building blocks of the PIX Firewall. After we have established how the PIX achieves basic firewalling, we will go into a more detailed discussion of some of the PIX's advanced features. As you will see in the following discussion, a firewall with just the basic features can cater to most of a simple network's needs. However, to increase the firewall's utility when you're faced with some of the more complicated application layer protocol connection setups and to increase the firewall's usefulness when you're faced with unique network topologies, some of the advanced features come in handy.