Chapter 2. How Does DNS Work?

"... and what is the use of a book," thought Alice, "without pictures or conversations?"

The Domain Name System is basically a database of host information. Admittedly, you get a lot with that: funny dotted names, networked name servers, a shadowy "namespace." But keep in mind that, in the end, the service DNS provides is information about internet hosts.

We've already covered some important aspects of DNS, including its client-server architecture and the structure of the DNS database. However, we haven't gone into much detail, and we haven't explained the nuts and bolts of DNS's operation.

In this chapter, we explain and illustrate the mechanisms that make DNS work. We also introduce the terms you'll need to know to read the rest of the book (and to converse intelligently with your fellow zone administrators).

First, though, let's take a more detailed look at concepts introduced in the previous chapter. We'll try to add enough detail to spice it up a little.