Border Gateway Protocol (BGP) is the routing protocol used to exchange routing information across the Internet. It makes it possible for ISPs to connect to each other and for end-users to connect to more than one ISP. BGP is the only protocol that is designed to deal with a network of the Internet's size, and the only protocol that can deal well with having multiple connections to unrelated routing domains. This book is a guide to all aspects of BGP: the protocol, its configuration and operation in an Internet environment, and how to troubleshooting it. The book also describes