Bounding Longest Match Considered

Document Type Expired Internet-Draft (grow WG)
Authors Russ White  , Ted Hardie 
Last updated 2003-06-03
Stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Expired & archived
plain text pdf htmlized bibtex
Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state Expired
Consensus Boilerplate Unknown
Telechat date
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


Some ASes currently use length-based filters to manage the size of the routing table they use and propagate. This draft explores an alternative to length-based filters which allows for more automatic configuration and which provides for better redundancy. Rather than use a filter, this draft proposes a method of modifying the BGP longest match algorithm by setting a bound on the prefix lengths eligible for preference. A bound would operate on long prefixes when covering route announcements are available; in certain circumstances it would cause a router to prefer an aggregate over a more specific route announcement.


Russ White (
Ted Hardie (

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