RFC 1164 (rfc1164) - Page 2 of 23
Application of the Border Gateway Protocol in the Internet
Alternative Format: Original Text Document
RFC 1164 BGP - Application June 1990 5.1 Overview.............................................. 17 5.2 Methods for Achieving Stable Interactions............. 17 5.2.1 Propagation of BGP Information via the IGP.......... 18 5.2.2 Tagged Interior Gateway Protocol.................... 18 5.2.3 Encapsulation....................................... 19 5.2.4 Other Cases......................................... 19 6. Implementation Recommendations......................... 20 6.1 Multiple Networks Per Message......................... 20 6.2 Preventing Excessive Resource Utilization............. 20 6.3 Processing Messages on a Stream Protocol.............. 21 6.4 Processing Update Messages............................ 21 7. Conclusion............................................. 22 References................................................ 22 Security Considerations................................... 22 Authors' Addresses........................................ 22 1. Acknowledgements The authors would like to thank Guy Almes (Rice University), Kirk Lougheed (cisco Systems), Hans-Werner Braun (Merit/NSFNET), Sue Hares (Merit/NSFNET), and the Interconnectivity Working Group of the Internet Engineering Task Force (chaired by Guy Almes) for their contributions to this paper. 2. Introduction The Border Gateway Protocol (BGP), described in RFC 1163, is an interdomain routing protocol. The network reachability information exchanged via BGP provides sufficient information to detect routing loops and enforce routing decisions based on performance preference and policy constraints as outlined in RFC 1104 [2]. This memo uses the term "Autonomous System" throughout. The classic definition of an Autonomous System is a set of routers under a single technical administration, using an interior gateway protocol and common metrics to route packets within the AS, and using an exterior gateway protocol to route packets to other ASs. Since this classic definition was developed, it has become common for a single AS to use several interior gateway protocols and sometimes several sets of metrics within an AS. The use of the term Autonomous System here stresses the fact that, even when multiple IGPs and metrics are used, the administration of an AS appears to other ASs to have a single coherent interior routing plan and presents a consistent picture of what networks are reachable through it. From the standpoint of exterior routing, an AS can be viewed as monolithic: reachability to networks directly connected to the AS must be equivalent from all border gateways of the AS. Interconnectivity Working Group
