Introduction

Border Gateway Protocol (BGP) is one of the most widely deployed protocols in networks today and is the de facto routing protocol in the Internet. BGP is a flexible protocol, in that a variety of options are available to network designers and engineers. Furthermore, extensions and implementation enhancements make BGP a powerful and complex tool.

The purpose of this book is to go beyond the basic protocol concepts and configurations and to focus on providing practical design and implementation solutions. BGP is treated as a useful tool in designing and implementing complex networks. Using a hands-on approach, details on Cisco IOS implementation are provided, with extensive examples and case studies throughout the book.

Who Should Read This Book?

This book is intended to cover advanced BGP topics in designing and implementing networks. Although basic concepts are reviewed, this book’s emphasis is not on BGP or basic BGP configurations. Practical design and implementation guidelines are provided to help network engineers, administrators, and designers build a scalable BGP routing architecture. This book can also be used by anyone who wants to understand advanced BGP features that are available in Cisco IOS and to prepare for Cisco certification exams.

How This Book Is Organized

The chapters in this book can be roughly grouped into four parts.

Part I, “Understanding Advanced BGP,” discusses and reviews some of the fundamental components and tools in BGP:

• Chapter 1, “Advanced BGP Introduction,” discusses the characteristics of BGP and compares BGP to IGP.

• Chapter 2, “Understanding BGP Building Blocks,” lays a foundation for the book by reviewing various components that are relevant to BGP.

• Chapter 3, “Tuning BGP Performance,” presents a detailed discussion of how to tune BGP performance, with emphasis on recent developments in IOS.

• Chapter 4, “Effective BGP Policy Control,” presents common policy control techniques that have made BGP so flexible.

Part II, “Designing BGP Enterprise Networks,” focuses on how to leverage BGP characteristics when designing an enterprise network:

• Chapter 5, “Enterprise BGP Core Network Design,” discusses various options in designing an enterprise core network using BGP.

• Chapter 6, “Internet Connectivity for Enterprise Networks,” presents design options for an enterprise network to connect to Internet Service Providers (ISPs) for Internet connectivity.

Part III, “Designing BGP Service Provider Networks,” focuses on BGP network designs for service providers:

• Chapter 7, “Scalable iBGP Design and Implementation Guidelines,” details the two options that are available to increase iBGP scalability: route reflection and confederation.

• Chapter 8, “Route Reflection and Confederation Migration Strategies,” presents several step-by-step procedures on network migrations between a fully meshed BGP network and networks that are based on route reflection and confederation.

• Chapter 9, “Service Provider Architecture,” discusses various BGP design options available for a service provider.

Part IV, “Implementing BGP Multiprotocol Extensions,” focuses on the multiprotocol extensions to BGP:

• Chapter 10, “Multiprotocol BGP and MPLS VPN,” discusses the BGP multiprotocol extension for MPLS VPNs and various design and implementation options to build complex VPN solutions.

• Chapter 11, “Multiprotocol BGP and Interdomain Multicast,” provides design options for how BGP is used for interdomain multicast.

• Chapter 12, “Multiprotocol BGP Support for IPv6,” presents the BGP extension for IP version 6.

Part V, “Appendixes,” provides the following information:

• Appendix A, Multiprotocol BGP Extensions for CLNS Support

• Appendix B, Matrix of BGP Features and Cisco IOS Software Releases

• Appendix C, Additional Sources of Information

• Appendix D, Acronym Glossary