Network Defense and Countermeasures: Principles and Practices, 4th Edition

Chapter 3

Fundamentals of Firewalls

Chapter Objectives

After reading this chapter and completing the exercises, you will be able to do the following:

• Explain how firewalls work.

• Evaluate firewall solutions.

• Differentiate between packet filtering and stateful packet filtering.

• Differentiate between application gateway and circuit gateway.

• Understand host-based firewalls and router-based firewalls.

Introduction

The first two chapters of this book discussed threats to network security and ways to defend against those threats. This and the following two chapters will address security devices. One of the most fundamental devices used to implement network security is the firewall. This is a key part of any security architecture. In fact, other ...