BGP MultiNexthop attribute
draft-kaliraj-idr-multinexthop-attribute-00

The information below is for an old version of the document
Document Type Expired Internet-Draft (individual)
Authors Kaliraj Vairavakkalai  , Jeyananth Jeganathan 
Last updated 2017-12-24 (latest revision 2017-06-22)
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at
https://www.ietf.org/archive/id/draft-kaliraj-idr-multinexthop-attribute-00.txt

Abstract

Today, a BGP speaker can advertise one nexthop for a set of NLRIs in an Update. This nexthop can be encoded in either the BGP-Nexthop attribute (code 3), or inside the MP_REACH attribute (code 14). For cases where multiple nexthops need to be advertised, BGP-Addpath is used. Though Addpath allows basic ability to advertise multiple- nexthops, it does not allow the sender to specify desired relationship between the multiple nexthops being advertised e.g., relative-preference, type of load-balancing. These are local decisions at the receiving speaker based on path-selection between the various additional-paths, which may tie-break on some arbitrary step like Router-Id. Some scenarios with a BGP-free core may benefit from having a mechanism, where egress-node can signal multiple-nexthops along with their relationship to ingress nodes. This document defines a new BGP attribute "MultiNexthop" that can be used for this purpose. This attribute can be used for both labeled and unlabled BGP families. For labeled-families, it is used for a different purpose in "downstream allocation" case than "upstream allocation" scenarios.

Authors

Kaliraj Vairavakkalai (kaliraj@juniper.net)
Jeyananth Jeganathan (minto@juniper.net)

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