RFC 2519 (rfc2519) - Page 1 of 13
A Framework for Inter-Domain Route Aggregation
Alternative Format: Original Text Document
Network Working Group E. Chen
Request for Comments: 2519 Cisco
Category: Informational J. Stewart
Juniper
February 1999
A Framework for Inter-Domain Route Aggregation
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1999). All Rights Reserved.
Abstract
This document presents a framework for inter-domain route aggregation
and shows an example router configuration which 'implements' this
framework. This framework is flexible and scales well as it
emphasizes the philosophy of aggregation by the source, both within
routing domains as well as towards upstream providers, and it also
strongly encourages the use of the 'no-export' BGP community to
balance the provider-subscriber need for more granular routing
information with the Internet's need for scalable inter-domain
routing.
1. Introduction
The need for route aggregation has long been recognized. Route
aggregation is good as it reduces the size, and slows the growth, of
the Internet routing table. Thus, the amount of resources (e.g., CPU
and memory) required to process routing information is reduced and
route calculation is sped up. Another benefit of route aggregation
is that route flaps are limited in number, frequency and scope, which
saves resources and makes the global Internet routing system more
stable.
Since CIDR (Classless Inter-Domain Routing) [2] was introduced,
significant progress has been made on route aggregation, particularly
in the following two areas:
- Formulation and implementation of IP address allocation policies
by the top registries that conform to the CIDR principles [1].
Chen & Stewart Informational