Routing domain

In the original definition and obsolete definition of the Border Gateway Protocol, Version 1 [ [ftp://ftp.rfc-editor.org/in-notes/rfc1105.txt A Border Gateway Protocol (BGP)] , RFC 1105, J. K. Lougheed & Y. Rekhter,June1989] , it was assumed that "A consistent view of the interior routes of the autonomous system is provided by the intra-AS routing protocol." It has become common, however, for an autonomous system to contain several instances of sets of routers and subnets, under one or more interior routing protocol, and with different metric assumptions. These instances are known as routing domains [ [ftp://ftp.rfc-editor.org/in-notes/rfc1237.txt Guidelines for OSI NSAP Allocation in the Internet] , RFC 1237, R. Collella "et al.",July1991] . This definition in RFC 1237, in turn, comes from the ISO Routeing [sic] Framework, [International Organization for Standardization. OSI Routeing Framework. Technical Report 9575, ISO/IEC JTC 1, Switzerland, 1989.] not available online.

A given autonomous system [ [ftp://ftp.rfc-editor.org/in-notes/rfc1930.txt Guidelines for creation, selection, and registration of an Autonomous System (AS)] , RFC 1930, J. Hawkison & T. Bates,March1996] can contain multiple routing domains, or a set of routing domains can be coordinated without being an Internet-participating autonomous system.

References