Introduction

Often, learning something new can be a chore, particularly with computer technology. In fact, because you've obviously been searching for a book long enough to at least have opened up this one, you've probably looked at a few other books as well. There's no problem finding networking booksthere are tons of thembut almost all of them are geared toward people who want to be networking geeks, and the books frequently get deep and technical in a hurry. They're like the old joke where one guy walks through a door with an unseen long drop to the ground below, and his buddy shouts out, "Watch out for that first step. It's a doozy!"

Computer Networking First-Step is an easy first step toward learning about networking, instead of taking a doozy of a step off the networking ledge. With Computer Networking First-Step, you don't have to worry about the pain normally associated with getting into something new. This book is designed and written assuming that you come to the game with no experience at all with the topics, but with a lot of interest in them.

This book is intended for anyone who needs to know a little about networking, but it also requires almost no prerequisite knowledge. You might want to know a little about networking, but not a lot, because that's all you need to know for your job. For instance, maybe you're in sales, and you need to be able to talk to networking geeks. Or maybe you work in another information technology (IT) area where you talk to the networking folks occasionally, and you need to be able to have more meaningful conversations. Or maybe you want to learn a lot about networking, but you aren't sure where to start. Simply put, if you're getting started with networking, this book is for you. If you've used a computer before, you've got the right prerequisite knowledge coming into this book.

When you finish reading this book, you will know enough to talk to people about how networks operate. You won't be an expert at any one part of networking, but you will understand the basic concepts behind a wide variety of technologies used in a typical network today. If your goal is to have a conversational level of knowledge, this book will do it for you. If your goal is to become a networking professional, but you don't have much knowledge or experience yet, this book will help you start down that path.

Interested? The next few pages will give you a little more detail about what's between the covers. Then you can dive in to the first chapter and start learning about networking!

There's a Lot Here, but Then Again, There's Not

Computer Networking First-Step covers a lot of topics, so there are many chapters, but each chapter averages 20 pages. And with the book's conversational style, you can grab it when you have 15 spare minutes and complete another chapter. If you're using this book to get started and want to learn networking even deeper, you'll want to take a few more minutes to study the questions and review the terms. In short, you'll find a lot of topics here, but they're pretty much in bite-sized pieces for easy digestion.

The part and chapter titles, as well as the headings inside the chapters, are purposefully nontechie. It seems silly to title things using terms that you might not have heard about before. But you might have heard of a few networking terms, so if you want a little better idea of the main topics in each major part of this book and each chapter, take a look at the following comments about what's hidden inside.

Part I: Networking Basics

Part I covers a broad brush of the basics of networking, with examples referencing tools that many computer users use every day:

• Chapter 1, "What Is a Network?" Defines the basic terms, including defining what different people might mean when they use the term "network."

• Chapter 2, "A Network's Reason for Existence" Covers networks and networking from a user's perspective.

• Chapter 3, "Building a Network: It All Starts with a Plan" Explains the concepts behind an architectural model that vendors use to build networking products and engineers use to implement a particular network.

Part II: Running the Local Department of (Network) Transportation

After Part I's broad coverage, Part II takes a closer look at the basics of small networks, called local-area networks (LANs), using analogies with how the U.S. Department of Transportation (DOT) builds roads:

• Chapter 4, "How to Build a Local (Network) Roadway" Using analogies with how the U.S. DOT builds roads, this chapter shows how to physically construct a LAN using cabling, PCs, and other networking gear.

• Chapter 5, "Rules of the Road: How to Use the Local (Network) Roadway" Just as you need to obey traffic laws, data must follow the traffic laws of the LAN. This chapter tells you how to pass a LAN driving test.

• Chapter 6, "Reducing Congestion and Driving Faster on the Local (Network) Roadway" It's more fun to drive a fast car. This chapter covers how to do the equivalent with LANs.

• Chapter 7, "Adding Local (Network) Roadways for No Extra Money" It's free, and it's better in many cases. "It" is a thing called virtual LANs (VLANs), which allow you to create lots of LANs with no additional hardware.

Part III: Shipping and Logistics: Commerce Using the (Network) Roadways

This part changes the focus to what the end user of a network experiencesthe applications. Chapters draw analogies with doing business by shipping goods to market over the roadways:

• Chapter 8, "Shipping Goods over a (Network) Roadway" This chapter focuses on applications that the end user of a network usesthings that you have probably already done yourself, such as use a web browser to look at a website.

• Chapter 9, "Choosing Shipping Options When Transporting the Goods over the (Network) Roadway" Behind the scenes, applications need services from other things in the network, just like most companies use a large shipping company for shipping products. This chapter looks at those basic services.

Part IV: Navigating the Roadways to Find the Right Street Address

The person driving the shipping truck needs to get to the right street address. Part IV covers the equivalent idea in networking, defining how data is delivered across any network, including the Internet:

• Chapter 10, "Delivering the Goods to the Right Street (IP) Address" Internet Protocol (IP) defines logical addressesthe equivalent of a street address. This chapter defines how networking devices together deliver data from one computer to another using IP addresses.

• Chapter 11, "Knowing Where to Turn at Each Intersection (Router)" One of the more important types of networking devices is called a router. This chapter covers how routers work, with analogies drawn to how a driver makes decisions about where to turn at each intersection.

• Chapter 12, "Painting the Road Signs on Your Interstate (Internetwork)" If you take a trip, you might rely on road signs to tell you where to turn. Routers can do the networking equivalent of posting road signs, which is explained in this chapter.

• Chapter 13, "People Like Names, but Computers Like Numbers" Let's face it: Computers are better at math than we are. This chapter explains how networks let us use names (such as www.ciscopress.com), and how the computer converts those names to numbers that are more useful to the computer.

Part V: Building an Interstate (Inter-LAN) Highway System

When computers in the network are far apart, the physical connections are called wide-area networks (WANs). This part explains three major branches of WANs, all of which require that you lease someone else's physical network because of the impracticality of having everyone run cables for hundreds of miles:

• Chapter 14, "Leasing a (Network) Roadway Between Two Points" This chapter covers how two routers at two different physical sites can send data using the equivalent of a never-ending telephone call between the two routers.

• Chapter 15, "Leasing a (Network) Roadway Between Lots of Places" If you have more than two routers at different sites, it's cheaper to use a different type of WAN, called Frame Relay, as explained in this chapter.

• Chapter 16, "Driving from Home onto the Globally Interconnected (Internet) Roadway" Most everyone knows about the Internet. But what really happens when you connect to the Internet from home? This chapter covers the high points.

Part VI: Securing the Network

This part highlights how to protect your network from both the curious and the malicious people on the Internet:

• Chapter 17, "Accepting the Right People and Rejecting the Wrong People" You shouldn't just let anyone use a network. This chapter hits the key points of how to make sure only the right people use your network.

• Chapter 18, "Keeping a Watchful Eye Over Who Drives into Your (Network) Neighborhood" This chapter covers how to set up ground rules for what's allowed into your network from the Internet, and how to watch for crackers who might try to cause harm to your network.

Part VII: Appendixes

• Appendix A, "Answers to Chapter Review Questions" Each chapter ends with a "Chapter Review Questions" section that contains some open-ended questions. This appendix repeats the questions and lists answers as well.

• Appendix B, "Converting IP Addresses Between Decimal and Binary" The coverage of IP in Chapter 10 doesn't require you to think about IP addresses in binary. However, for any of you who are interested in learning networking more deeply after reading this book, this appendix can help you with some of the basic math relating to IP addressing.

Glossary

The college professor who first taught me about networking, Dr. Phil Enslow, used to say that 80 percent of networking was understanding the lingo and then understanding how other people used the same lingo. The Glossary will be a valuable tool as you build up your lexicon for having conversations about networking.