Chapter 7. What Are Firewalls?

This chapter covers the following key topics:

• Firewalls- This section defines firewalls and lays the groundwork for discussing firewall products.

• Types of Firewalls- This section talks about the different kinds of firewalls in place in the industry today.

• Positioning of Firewalls- This section describes the important concept of positioning a firewall in a network.

Firewalls are an integral part of any secure network. As we continue the discussion of the various security features and designs, it is important to take an in-depth look at how firewalls protect a network.

This chapter is the first in a series of three chapters on firewalls. This chapter lays the foundation for an understanding of what firewalls in general are. We will discuss some of the most common features of firewalls and how these features are used to make a network secure. The next two chapters use the technical foundation built in this chapter to analyze the PIX and IOS firewalls.