Inter-domain routing in the Internet has evolved rather than arrived. From its 1988 start, each step in the evolution BGP has been spurred on by real problems in the Internet. This talk will examine the network events and challenges that have caused each stage of the BGP evolution over the last 15 years and will point to possible future steps in the evolution of inter-domain routing.

Taking a look from a true insider's point of view, the talk will discuss how BGP has evolved with the Internet's needs from BGP version 1 to BGP version 4 to multi-protocol BGP. Of note, BGP version 3 was built to support default routes in a domain and BGP-4 was initially created to support early CIDR deployment. The latest version of the BGP-4 brings the BGP specification in-line with BGP implementations fielded in the Internet. Beyond basic BGP, multi-protocol BGP supports MPLS or multicast in multi-protocol BGP (BGP-4+). These additions include support scalability in the Internet and high availability. In 2000-2001, the Internet Engineering Task Force (IETF) became concerned about the BGP infrastructure and its ability to scale. Discussion will also cover the work of the Internet Research Task Group's (IRTFs) Routing Research experts meetings to determine requirements for the next generation routing protocols.