Browse Prior Art Database

BGP Route Flap Damping (RFC2439)

IP.com Disclosure Number: IPCOM000003017D
Original Publication Date: 1998-Nov-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 30 page(s) / 80K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

C. Villamizar: AUTHOR [+3]

Abstract

A usage of the BGP routing protocol is described which is capable of reducing the routing traffic passed on to routing peers and therefore the load on these peers without adversely affecting route convergence time for relatively stable routes. This technique has been implemented in commercial products supporting BGP. The technique is also applicable to IDRP.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 3% of the total text.

Network Working Group C. Villamizar

Request for Comments: 2439 ANS

Category: Standards Track R. Chandra

Cisco

R. Govindan

ISI

November 1998

BGP Route Flap Damping

Status of this Memo

This document specifies an Internet standards track protocol for the

Internet community, and requests discussion and suggestions for

improvements. Please refer to the current edition of the "Internet

Official Protocol Standards" (STD 1) for the standardization state

and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (1998). All Rights Reserved.

Abstract

A usage of the BGP routing protocol is described which is capable of

reducing the routing traffic passed on to routing peers and therefore

the load on these peers without adversely affecting route convergence

time for relatively stable routes. This technique has been

implemented in commercial products supporting BGP. The technique is

also applicable to IDRP.

The overall goals are:

o to provide a mechanism capable of reducing router processing load

caused by instability

o in doing so prevent sustained routing oscillations

o to do so without sacrificing route convergence time for generally

well behaved routes.

This must be accomplished keeping other goals of BGP in mind:

o pack changes into a small number of updates

o preserve consistent routing

o minimal addition space and computational overhead

An excessive rate of update to the advertised reachability of a

subset of Internet prefixes has been widespread in the Internet.

This observation was made in the early 1990s by many people involved

in Internet operations and remains the case. These excessive updates

are not necessarily periodic so route oscillation would be a

misleading term. The informal term used to describe this effect is

"route flap". The techniques described here are now widely deployed

and are commonly referred to as "route flap damping".

1 Overview

To maintain scalability of a routed internet, it is necessary to

reduce the amount of change in routing state propagated by BGP in

order to limit processing requirements. The primary contributors of

processing load resulti...