Introduction

TCP/IP is the glue that holds together the Internet and the World Wide Web. To be well connected (network-wise, that is), sooner or later you have to become familiar with TCP/IP applications and services. If you want to understand what TCP/IP is, what it's for, why you need it, and what to do with it, and you just don't know where to start — this book is for you.

If you're on a network, whether you know it or not, odds are, you're working with TCP/IP and its many pieces and parts. We help you understand how it all fits together. We also give you plenty of hands-on tips so that you can get all those pieces and parts set up and running.

We take the mystery out of TCP/IP by giving you down-to-earth explanations for all the buzzwords and technical jargon that TCP/IP loves.

This isn't a formal tutorial; skip around and taste TCP/IP in little bites. If you need to impress your boss and colleagues with buzzwords, you can find out just enough to toss them around intelligently with the technocrats at meetings and parties. Or, you can go further and discover how to set up and use the most important features and tools. If you want the full TCP/IP banquet, you can explore the technical tasks that take place behind the scenes to make the Internet and the Web work. It's right here in your hands.

About This Book

We hope you find TCP/IP For Dummies, 6th Edition, to be a fun and fast way to dive into the guts of the Internet. The book is both an introduction to the basics and a reference to help you work with Internet applications and tools on all kinds of connected computers. We added and updated the latest Internetworking protocols and servers — with examples from Microsoft Windows Server 2008, Windows 7, Windows Vista, Windows XP, Linux, Unix, and Mac OS X. Here are just a few of the subjects we describe:

• Uncover the relationships among TCP/IP, the Net, and the Web.

• Get up and running and keep running on the Internet, whether you have a small network or a big enterprise network and whether it's wired or wireless.

• Install and configure TCP/IP client and server applications and services.

• Phone home without the phone or the bill, thanks to VoIP.

• Build and enforce security everywhere on your network.

• Get in on all the newest Internet security protocols and trends.

• Boldly go to the next generation: IPv6.

This book is loaded with information. But don't try to read it from cover to cover in one sitting — you may hurt yourself. If your head explodes and bits and bytes go flying, please don't blame us.

Conventions Used in This Book

All commands that you need to enter yourself appear either in bold, like this, or on a separate line, like this:

COMMAND to type

To enter this command, you type COMMAND to type exactly as you see it here and then press Enter.

When you type commands, be careful to use the same upper- and lowercase letters that we show you. (Some computer systems are fussy about this issue.)

When we want you to move through a series of menus or buttons, we say "Click" once and then point to the next place with a command arrow ().

Whenever we show you something that's displayed onscreen (such as an error message or a response to your input), it looks like this:

A TCP/IP message on your screen

Foolish Assumptions

In writing this book, we tried not to make too many assumptions about you. We figure that you've done a little Web browsing and e-mailing. Our only assumption is that you're not really a dummy — you're just trying something new. Good for you!

How This Book Is Organized

This book contains five parts, each of which contains several chapters. We don't expect you to read the whole book from cover to cover, but please feel free to do so. Instead, you can glance at the table of contents for the topic you're interested in and go from there. The layout of the book is easy to follow. Here's a quick look at what you can find in each major part.

Part I: TCP/IP from Names to Addresses

Part I starts at the beginning with the buzzwords and how TCP/IP and the Internet are joined at the hip. You also find out that, contrary to its name, TCP/IP is so much more than just two protocols. We give you a quick look at the most important protocols, and you get to see all the lingo that should take you far through this century.

You'll find that as much as people like names, computers like numbers even more. After you get some of the buzzwords under your belt, the chapters in Part I explain what an Internet protocol (IP) address is, how to build one, how to use it, and how to be frugal and save enough Internet addresses for someone else. We clue you in on different ways to make IP addresses go further. No worries — the Internet won't get full.

Part II: Getting Connected

After you know how IP addresses are constructed, we move on to setting up your TCP/IP network, both wired and wireless, to connect to the world (the Internet). In this part of the book, we show you how hardware and software work together to make a network. We discuss just the minimum hardware you need to understand.

Then we throw in IPv6, which puts you ahead of most people in understanding the next generation of Internet addresses. If you're not ready to go where no one (well, hardly anyone) has gone before, don't worry — you can skip Chapter 9 entirely.

Part III: Configuring Clients and Servers: Web, E-Mail, and Chat

TCP/IP is a big set of protocols, services, and applications. Whether you're aware of it or not, you use TCP/IP applications and services to do everything from reading news to exchanging e-mail and online conversations with your friends to copying good stuff like games, technical articles, and even TCP/IP itself. This section explains how these applications and services work behind the scenes with client/server technology. The numerous hands-on sections help you configure popular applications and services for both clients and servers.

Security is one of the stars of Part III. Hackers love to try to break into your Web, e-mail, and chat applications, and we love to show you how to thwart their every move. We throw in a quick-start security guide to get you going. If you're interested in online shopping or banking, we walk you through a secure Internet credit card transaction.

Part IV: Even More TCP/IP Applications and Services

"How could there possibly be more?" you might ask. Well, we told you that TCP/IP consists of much more than just a couple of protocols — for example, there's Mobile IP, for when you take your laptop to your favorite café rather than to your office. If you have a smartphone or organizer, such as a Palm or BlackBerry, you need to know this stuff. But wait! There's more. How about saving big bucks on phone calls? With or without a phone? Voice over Internet Protocol, or just VoIP, lets you make calls, even international ones, for free. Finally, Part IV covers remote access applications, from sharing files to working on someone else's computer when you're 5,000 miles away.

Part V: Network Troubleshooting and Security

Part V delves into some advanced topics. If you're a system or network administrator, you may need to know more than just the basics about network hardware. We hope that after you install and configure TCP/IP and your network applications, nothing ever goes wrong for you, but stuff happens. Part V steps you through a basic troubleshooting procedure so that you can figure out what went wrong and where. Then you can fix it.

The rest of Part V is devoted to security. You find practical security tips, and you can delve deeper, to see how to use encryption, authentication, digital certificates, and signatures. You get hands-on advice for setting up a software firewall and the Kerberos authentication server.

Part VI: The Part of Tens

You may already know that every For Dummies book has one of these parts. In it, you can find security tips, Internet traffic factoids, advice about places to go and things to do (even if you never leave your computer), and more security pointers. And all this happens in, roughly, sets of ten.

Icons Used in This Book

Indicates nifty shortcuts that make your life easier.

Lets you know that a loaded gun is pointed directly at your foot. Watch out!

Where to Go from Here

Check out the table of contents or the index and decide where you want to start. If you're an information technology manager, you're probably interested in buzzwords and you know why everyone is on the TCP/IP bandwagon. If you're a system or network administrator, start with Chapter 2 or 4, where we describe the major protocols and what they do. Chapters 12, 14, 20, and 21 talk about Internet security — a topic that's for everyone concerned that their personal data is at risk.

Or, you can just turn the pages one by one. We don't mind. Really.