Part III describes how to establish a security policy for your site, maintain your firewall, and handle the security problems that may occur with even the most effective firewalls.
Chapter 11, Security Policies, discusses the importance of having a comprehensible and well-understood security policy for your site, and what that policy should and should not contain. It also discusses ways of getting management and users to buy into the policy.
Chapter 12, Maintaining Firewalls, describes how to maintain security at your firewall over time and how to keep yourself aware of new Internet security threats and technologies.
Chapter 13, Responding to Security Incidents, describes what to do when a breakin occurs, or when you suspect that your security is being breached.