Chapter 23
Before computer jargon made a large impact on our collective vocabulary, the word firewall meant a physical structure that is used to prevent the spread of a fire, or, more generally, a device that limits the damage an existing menace can inflict. Today, if you hear people talking about a firewall, they’re probably discussing protecting computers from Internet-based rogue programs (unless they’re firefighters).
In this chapter, we’ll explain what a firewall does and provide information about installing, configuring, and using two of the most popular firewall applications: ZoneAlarm Pro and BlackIce. We’ll cover the following topics: