Foundations of Python Network Programming: The comprehensive guide to building network applications with Python, Second Edition

Chapter 4. Socket Names and DNS

Having spent the last two chapters learning the basics of UDP and TCP, the two major data transports available on IP networks, it is time for us to step back and talk about two larger issues that need to be tackled regardless of which transport you are using. In this chapter, we will discuss the topic of network addresses and will describe the distributed service that allows names to be resolved to raw IP addresses.

Hostnames and Domain Names

Before we plunge into this topic, we should get a few terms straight that will play a big role in the discussion that follows.

• Top-level domain (TLD): These are the few hundred strings like com, net, org, gov, and mil that, together with country codes like de and uk, form the ...