Practical BGP
Preface
"Experience is the best teacher" is a valuable truism in network design, especially in designing a routed network using a protocol as widespread, and as little understood, as the Border Gateway Protocol (BGP). It's hard to grasp BGP at a high level, because network engineers tend to see only a small piece of the system they are interacting with—either their connection to the Internet, or their network backbone, or some other slice. From this perspective, it's hard to understand how BGP works in the real world, and what impact decisions in one small slice of the network will actually have in the larger internetwork.
How, for instance, does BGP express policy? And what is the difference between a routing protocol that expresses policy versus one that "just" provides routing information? When should I use BGP, and when should I not? What are the most common policy mechanisms used in BGP, and how are they expressed? What do I do when everything falls apart?
These, and many other questions, are the questions we set out to answer in this book. So, while this is a book about BGP, it's actually a book about network design and deployment. We hope, through this book, you can learn from our experience in deploying BGP, both our failures and our successes, in all types of environments, from small enterprise networks to large-scale service providers. In Practical BGP, you will find help in deciding where to use BGP and where not to, as well as techniques for designing, deploying, managing, and troubleshooting BGP networks.
We hope you enjoy the fruit of our labors and experience (and not just for its ability to put you to sleep).
Russ White
Danny McPherson
Sangli Srihari |
