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AS-Path Prepend

Document Type Replaced Internet-Draft (individual)
Authors Mike McBride , Doug Madory , Jeff Tantsura
Last updated 2020-07-26
Replaced by draft-ietf-grow-as-path-prepending
Stream (None)
Intended RFC status (None)
Expired & archived
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Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Replaced by draft-ietf-grow-as-path-prepending
Telechat date (None)
Responsible AD (None)
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at:


AS_Path prepending provides a tool to manipulate the BGP AS_Path attribute through prepending multiple entries of an AS. AS_Path prepend is used to deprioritize a route or alternate path. By prepending the local ASN multiple times, ASes can make advertised AS paths appear artificially longer. Excessive AS_Path prepending has caused routing issues in the internet. This document provides guidance,to the internet community, with how best to utilize AS_Path prepend in order to avoid negatively affecting the internet.


Mike McBride
Doug Madory
Jeff Tantsura

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)