book allows me to teach more people than I'd ever thought possible. I hope you will find the discussions both informative and enjoyable. I have noticed over the years that people in the computer, networking, and telecom industries are often misinformed about the basics of these disciplines. I believe that in many cases, this is the result of poor teaching or the use of reference material that does not convey complex concepts well. With this book, I hope to show people how easy some of these concepts are. Of course, as I like to say, "It's easy when you know how," SO I have tried very hard to help anyone who picks up my book understand the ideas contained herein. If you are reading this, my guess is that you would like to know more about networking. So would I! Learning should be a never-ending adventure, and I am honored that you have let me be a part of your journey. I have been studying and learning about com- puters, networking, and telecom for the last 29 years, and my journey will never end. xviii Preface This book does not explain the OSI stack, but it does briefly explain the differences between hubs, switches, and routers. You will need to have a basic understanding of what Layer 2 means as it relates to the OSI stack. Beyond that, this book tries to cover it all, but not like most other books. This book attempts to teach you what you need to know in the real world. When should you choose a Layer-3 switch over a Layer-2 switch? How can you tell if your network is performing as it should? How do you fix a broadcast storm? How do you know you're having one? How do you know you have a spanning tree loop, and how do you fix it? What is a T1, or a DS3 for that matter? How do they work? In this book, you'll find the answers to all of these questions and many, many more. I tried to fill this book with information that many network engineers seem to get wrong through no fault of their own. Network Warrior includes configuration examples from real-world events and designs, and is littered with anecdotes from my ti