Introduction

I have been involved with the world of networking from many directions. My experiences in education, network consulting, service provider support, and certification have shown me that there is a common thread that frustrates people in all of these arenas. That common thread is documentation. There are many factors that cause documentation to be frustrating but the most common are amount, clarity, and completeness. The amount of documentation available, especially in regards to BGP, can be overwhelming. For a person who is beginning to learn BGP, the question is "where do I begin"? There are very good books, RFCs, white papers, and command references available, but it is difficult to know where to start. The clarity of documentation depends on your personal situation. For a seasoned BGP designer the documentation may be clear and concise. To an individual preparing for a professional certification such as the CCIE the same documentation may be confusing. Even if the documentation is clear it is sometimes not complete. You may understand the words but be confused on the application. The purpose of this book is to provide a BGP handbook that is clear, concise , and complete. This book is not meant to be read from cover to cover. The way you use this book will depend on your objectives. If you are preparing for the CCIE written and lab exams then this book can be used as a laboratory guide to learn the purpose and proper use of every BGP command. If you are a network designer then this book can be used as a ready reference for any BGP command. In order to satisfy these varying audiences the structure of this book is reasonably simple. Each BGP command is illustrated using the following structure:

• Listing of the command structure and syntax

• Syntax description for the command with an explanation of all command parameters

• The purpose of the command and the situation where the command is used

• The first release of the IOS in which the command appeared

• One or more configuration examples to demonstrate the proper use of the command

• Procedures and examples to verify that the command is working properly

• How to troubleshoot the command when things are not working as intended.

The example scenarios that demonstrate the proper use of the BGP commands can be implemented on a minimum number of routers. This will allow you to learn each command without requiring an extensive and expensive lab configuration. The scenarios are presented so that the purpose and use of each command can be presented without clouding the issue. Some of the examples lead you into common non-working situations in order to reinforce the understanding of the operation of the particular BGP command.

For those of you who will use this book as a tool for preparing for the BGP component of the CCIE exam I would suggest that you read Appendix A, B, and C before diving into the various command examples. Appendix A is an overview of BGP operation and concepts. Appendix B is a review of regular expressions and their use with BGP. Appendix C covers the structure, logic, and use of route maps. Regular expressions and route maps tend to be areas where candidates typically run into trouble on the CCIE lab exam. My hope is that this handbook will help you prepare for the CCIE exam, allow you to properly use BGP in your network, or both.