Chapter 3. Basics of the PIX Firewall

Terms you'll need to understand:

• Inside (trusted)

• Outside (untrusted)

• DMZ

• Bastion hosts

• Packet filters

• Proxy filters

• Stateful packet filters

• Embedded operating system

• URL filtering

• Failover, hot standby

• Activation keys

Techniques you'll need to master:

• Security levels

• Software licensing

• Adaptive Security Algorithm (ASA)

• Cut-Through proxy

• Traffic flow

• Hardware differences between models

There are several areas of a network in a secure environment; the most common are the inside, the outside, and the DMZ firewalls that help divide and control traffic between them. Cisco has designed the PIX series of firewalls to be the primary devices for performing these functions. This chapter covers the basics of the PIX firewall areas that connect to the firewall ”the trusted, untrusted, and DMZ.