Beyond interdomain reachability

The Border Gateway Protocol (BGP) was designed as a successor to the Exterior Gateway Protocol. BGP started as a subset of the IDRP protocol [ISO93] being developed by ISO. During the last ten years, BGP has evolved in an incremental and backward compatible manner. In the early nineties, the main objective of BGP was to make possible the distribution of routes constrained by routeing policies, such as those of the NSFNet. As such, BGP mainly provided reachability information and this was the main concern for most Autonomous Systems since the Internet was being built. Since then, the Internet has grown tremendously, both in size and economical importance. Today, the Internet is composed of different domains. Among those domains, only provide a transit service. Thus, most of the domains on the global Internet are stub domains. Stub domains include enterprise networks or universities, content providers and access providers.