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Autonomous confederations (RFC0975)

IP.com Disclosure Number: IPCOM000004973D
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2001-Jul-13
Document File: 11 page(s) / 27K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

D.L. Mills: AUTHOR

Abstract

The historical development of Internet exterior-gateway routing algorithms began with a rather rigid and restricted topological model which emphasized robustness and stability at the expense of routing dynamics and flexibility. Evolution of robust and dynamic routing algorithms has since proved extraordinarily difficult, probably due more to varying perceptions of service requirements than to engineering problems.

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Network Working Group D. L. Mills Request for Comments: 975 M/A-COM Linkabit

February 1986

Autonomous Confederations

Status of This Memo

This RFC proposes certain enhancements of the Exterior Gateway Protocol (EGP) to support a simple, multiple-level routing capability while preserving the robustness features of the current EGP model. It requests discussion and suggestions for improvements. Distribution of this memo is unlimited.

Overview

The enhancements, which do not require retrofits in existing implementations in order to interoperate with enhanced implementations, in effect generalize the concept of core system to include multiple communities of autonomous systems, called autonomous confederations. Autonomous confederations maintain a higher degree of mutual trust than that assumed between autonomous systems in general, including reasonable protection against routing loops between the member systems, but allow the routing restrictions of the current EGP model to be relaxed.

The enhancements involve the "hop count" or distance field of the EGP Update message, the interpretation of which is not covered by the current EGP model. This field is given a special interpretation within each autonomous confederation to support up to three levels of routing, one within the autonomous system, a second within the autonomous confederation and an optional third within the universe of confederations.

1. Introduction and Background

The historical development of Internet exterior-gateway routing algorithms began with a rather rigid and restricted topological model which emphasized robustness and stability at the expense of routing dynamics and flexibility. Evolution of robust and dynamic routing algorithms has since proved extraordinarily difficult, probably due more to varying perceptions of service requirements than to engineering problems.

The original exterior-gateway model suggested in RFC-827 [1] and subsequently refined in RFC-888 [2] severely restricted the Internet topology essentially to a tree structure with root represented by the BBN-developed "core" gateway system. The most important characteristic of the model was that debilitating resource-consuming routing loops between clusters of gateways (called autonomous

Mills [Page 1]

RFC 975 February 1986 Autonomous Confederations

systems) could not occur in a tree-structured topology. However, the administrative and enforcement difficulties involved, not to mention the performance liabilities, made widespread implementation impractical.

1.1. The Exterior Gateway Protocol

Requirements for near-term interoperability between the BBN core gateways and the remainder of the gateway population implemented by other organizations required that an interim protocol be developed with the capability of exchanging reachability information, but not necessarily the capability to function as a true routing algorithm. This protocol is called the Exterior Gateway Protocol (EGP) and is documented in RFC-904 [3].

EGP was not designed as ...