Networking All-in-One For Dummies, 7th Edition

Chapter 3

IP Addresses

IN THIS CHAPTER

Delving into the binary system

Digging into IP addresses

Finding out how subnetting works

Looking at network address translation

One of the most basic components of TCP/IP is IP addressing. Every device on a TCP/IP network must have a unique IP address. In this chapter, I describe the ins and outs of these IP addresses. Enjoy!

Understanding Binary

Before you can understand the details of how IP addressing works, you need to understand how the binary numbering system works because binary is the basis of IP addressing. If you already understand binary, please skip to the section “Introducing IP Addresses.” I don’t want to bore you with stuff that’s too basic.

Counting by ones

Binary is a counting system that uses only two numerals: 0 and 1. In the decimal system (with which most people are accustomed), you use ten numerals: 0–9. In an ordinary decimal number — such as 3,482 — the rightmost digit represents ones; the next digit to the left, tens; the next, hundreds; the next, thousands; and so on. These digits represent powers of ten: first ...