Part I
TCP/IP from Names to Addresses
In this part . . .
You canât play the game if you donât know the rules. And TCP/IP is the set of rules, or protocols, for networks. TCP/IP is the software underpinning of the Internet and its World Wide Web. TCP/IP also includes services and applications that work with the protocols. Before we get into the hairy details of the protocols themselves, we give you some background on the people and committees who decide the direction of TCP/IPâs growth. Did you know that you can be part of these groups? We tell you how. You also become familiar with TCP/IP and Internet buzzwords.
Part I then delves into the ingredients of the TCP/IP suite: the protocols and services themselves and IP addressing. You see how the protocols fit into the layers of the TCP/IP network model, and you take a look at the most important ones. TCP/IP is a suite because it consists of more protocols than the two itâs named for, plus a set of services and applications. The TCP/IP protocols, services, and applications in the suite work together just like the rooms in a hotel suite or the pieces in a furniture suite work together. The set of protocols is also referred to as a stack.
From there, we go into Internet addressing.
People love names. Computers love numbers. Youâll hear this in each part of this book.
If your computer is named Woodstock, for example, the Internet may think of it as 198.162.1.4. You get to see how to build and understand these numeric addresses. Also, if youâre worried because you think that the Internet is running low on addresses, Part I eases your worries by cluing you in to a couple of different ways to make IP addresses go further: subnetting and NAT (Network Address Translation).
Bear in mind that TCP/IP stays alive by morphing regularly â at times, daily. So, the list of protocols we describe here â the Internetâs rules â will be even longer by the time you read this book.
Chapter 1
Understanding TCP/IP Basics
In This Chapter
Protocols in this chapter: IP, TCP, IPSec, PPTP, L2TP
Introducing TCP/IP
Defining a protocol
Understanding RFCs â the protocol documentation
Differentiating between intranets, extranets, and Virtual Private Networks (VPNs)
Figuring out whoâs in charge of TCP/IP and the Internet
Investigating different types of networks that rely on TCP/IP software
You bought or borrowed this book, or maybe youâre just flipping through it to pick up some information and tips about TCP/IP and its pieces and parts. Transmission Control Protocol/Internet Protocol, or TCP/IP, is the internationally accepted software for networking in general and, specifically, for making the Internetâs services possible.
As you read this book, you get a behind-the-scenes look at how TCP/IP makes the Internet work. You also see how to use TCP/IP to set up your own home, office, or even international network. This chapter gets started by defining a protocol in general and TCP/IP protocols specifically. Proposals known as Requests for Comment, or RFCs, document how TCP/IP should function. You may wonder whoâs in charge of defining these protocols that rule the Internet. The answer is: lots of people who join international committees. This chapter describes the main Internet governing committees and what they do.
The Internet is one giant worldwide network that consists of tens of thousands of other networks. We give you an idea in this chapter of the different kinds of networks that connect via TCP/IP into the Internet.
Following Rules for the Internet: TCP/IP Protocols
A protocol is a set of behavior-related rules that people follow. Some protocols are formally defined. For example, when people meet and greet each other, they might say, âEnchante de faire votre conaissanceâ or âHow do you doâ? We also hear our niece, Emily, and her friends saying âHey, dude!â All these examples are widely accepted behaviors for people to start communicating â they are protocols. The more formal greetings are written down in etiquette books. âHey, dudeâ has become accepted (at least by people much younger than we are) because of its wide use. Common ways of connecting arenât enough, though. After you meet, you need a common language in order to communicate. Just as people connect and communicate in accepted ways, computers connect and communicate with each other and with you. In the world of computers and networks, TCP/IP is a common language used for both connection and communication.
Although TCP/IP sounds like it consists of just two protocols, itâs a whole set of protocols for connecting computers to the Internet. This set of protocols is the TCP/IP stack, or protocol suite. We describe in Chapter 2 the most well-known protocols in the TCP/IP stack. Before we get to the protocols themselves, the following sections look at whoâs in charge of the Internet and who decides what gets to be a standard part of the TCP/IP protocol suite. You also get familiar with Requests for Comments (RFCs), the documents that describe TCP/IP standards.
Whoâs in charge of the Internet and TCP/IP?
Youâre in charge. Or, you might say that everyone is, and no one is, in charge of the Internet and TCP/IP. No one person, organization, corporation, or government owns or controls the TCP/IP protocols or the Internet. Moreover, no one person, organization, corporation, or government finances the TCP/IP...
