A Border Gateway Protocol 4
RFC 4271, “A Border Gateway Protocol 4”, is a Draft Standard document published in January 2006 by Y. Rekhter, T. Li, S. Hares. It obsoletes RFC 1771. It has since been updated by RFC 4724, RFC 6286, RFC 6608, RFC 6793, RFC 7606, RFC 7607, RFC 7705, RFC 8212, RFC 8654, RFC 9072, RFC 9687, RFC 9774. The canonical text is published by the RFC Editor.
Abstract
This document discusses the Border Gateway Protocol (BGP), which is an inter-Autonomous System routing protocol.
The primary function of a BGP speaking system is to exchange network reachability information with other BGP systems. This network reachability information includes information on the list of Autonomous Systems (ASes) that reachability information traverses. This information is sufficient for constructing a graph of AS connectivity for this reachability from which routing loops may be pruned, and, at the AS level, some policy decisions may be enforced.
BGP-4 provides a set of mechanisms for supporting Classless Inter-Domain Routing (CIDR). These mechanisms include support for advertising a set of destinations as an IP prefix, and eliminating the concept of network "class" within BGP. BGP-4 also introduces mechanisms that allow aggregation of routes, including aggregation of AS paths.
This document obsoletes RFC 1771. [STANDARDS-TRACK]
What “Draft Standard” means
A historical maturity level (retired in 2011) that sat between Proposed Standard and Internet Standard and required multiple interoperable implementations.
The canonical text of RFC 4271 is hosted at rfc-editor.org. Available in TXT,HTML.
- RFC 4272 BGP Security Vulnerabilities Analysis
- RFC 4273 Definitions of Managed Objects for BGP-4
- RFC 4274 BGP-4 Protocol Analysis
- RFC 4275 BGP-4 MIB Implementation Survey
- RFC 4276 BGP-4 Implementation Report
- RFC 4277 Experience with the BGP-4 Protocol
- RFC 4278 Standards Maturity Variance Regarding the TCP MD5 Signature Option and the BGP-4 Specification
- RFC 4263 Media Subtype Registration for Media Type text/troff