Chapter 8: Networking

Overview

TCP/IP:
Learn how it fits together,
You cannot escape.

BSD is famous for its network performance. In fact, the TCP/IP network protocol itself was first developed in the days when BSD lived in Berkeley, and BSD was the first major deployment of TCP/IP. Many other operating systems have chosen to use the BSD network stack because of its high performance and liberal licensing. While other protocols were considered more exciting during the 1980s, the wide availability of the BSD stack made it the de facto standard.

Many systems administrators today have a vague familiarity with some of the basics of networking, but don't really understand how it all hangs together. Good sysadmins come from all walks of life, but they all have one thing in common: They understand the network. Knowing what an IP address really is, how a netmask really works, and what a port number means is part of what transforms a novice into a professional. We'll cover some of these issues here.

Note

TCP/IP is a very dense topic, with many details, "gotchas," and caveats. While this section gives a good overview, we cannot possibly cover everything. If you want to know more about TCP/IP, pick up one of the big thick books on the subject. My favorite is Stevens' s TCP/IP Illustrated, volumes 1 through 3.