Border Gateway Protocol defines how backbone routing (i.e., routing on a line carrying data gathered from smaller lines) is carried out on the Internet or large intranets/extranets. BGP differs from its alternatives in that it is an industrial-strength routing protocol suitable for use in high-bandwidth backbone environments. Soon, all non-local Internet traffic will be routed via BGP, and, as intranets/extranets become more complex, BGP will become even more important in the corporate environment. Indeed, this transition is already in progress, and engineers are scrambling for precisely the sort of in-depth, reliable information on BGP that this volume provides.