Foundations of Mac OS X Leopard Security

CHAPTER 8Setting Up theMac OS X Firewall

Put simply, a firewall is a network traffic moderator. It uses a set of rules to determine what kind of traffic is allowed in and out of your computer or network. The word firewall can be ambiguous because there are a variety of types of firewalls. In Chapter 2, we discussed the importance of using a firewall to act as a gateway into your network, denying and allowing network traffic on a network-wide basis between your computers and the outside world. This is what we refer to as a hardware appliance firewall.

For the purposes of this chapter, we will discuss the intricacies of the built-in firewall of Mac OS X, the software in your operating system that determines which traffic your computer will accept. ...