Enterprise Mac Security: Mac OS X Snow Leopard

11.1. Introducing Network Services

The primary purpose behind most network traffic is for computers to communicate with one another. There are a wide variety of communication paths, or routes, that computers take to do this. And there are different purposes, or roles, for these varied communication paths. One communication path might have the intent of sending printing commands to a printer, while another might need to send an Internet request to an Internet gateway, or router. A network service then communicates with other devices using a structured mechanism for conversing, known as a protocol. For firewalls to manage these various protocols, they use rules. A rule is a set of parameters that enables the firewall to allow or deny access to ...