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Inter-Domain Routing

Document Charter Inter-Domain Routing WG (idr)
Title Inter-Domain Routing
Last updated 2024-03-20
State Approved
WG State Active
IESG Responsible AD John Scudder
Charter edit AD John Scudder
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The Inter-Domain Routing Working Group is chartered to standardize,
develop, and support the Border Gateway Protocol Version 4 (BGP-4)
[RFC 4271] capable of supporting policy based routing for TCP/IP

The main objective of the working group is to support the use of
BGP-4 by IP version 4 and IP version 6 networks. The working group
will also continue to work on improving the robustness and
scalability of BGP.

IDR will review extensions made to BGP in other working groups at least
at WG document adoption and during working group last calls. The IDR
working group will also provide advice and guidance on BGP to other
working groups as requested.

Work Items:

The IDR working group will work on correctness, robustness and
scalability of the BGP protocol, as well as clarity and accuracy of the
BGP document set. The group will also work on extensions beyond these
areas when specifically added to the charter. The current additional
work items are:

  • Relax the definition of BGP identifiers to only require AS-wide
    uniqueness. This change must be made in a backward compatible way.

  • Specify a means to non-disruptively introduce new BGP Capabilities
    to an existing BGP session.

  • Upgrade of the base BGP specification to Full Standard

  • Define AS_PATH based Outbound Route Filtering.

  • MIB v2 for BGP-4

  • Augment the BGP multiprotocol extensions to support the use of
    multiple concurrent sessions between a given pair of BGP speakers.
    Each session is used to transport routes related by some session-
    based attribute such as AFI/SAFI. This will provide an alternative
    to the MP-BGP approach of multiplexing all routes onto a single

  • Support for four-octet AS Numbers in BGP.

  • Revisions to the BGP 'Minimum Route Advertisement Interval'
    deprecating the previously recommended values and allowing for
    withdrawals to be exempted from the MRAI.

  • Advertisement of multiple paths for the same address prefix without
    the new paths implicitly replacing any previous ones. Each path is
    identified by a path identifier in addition to the address prefix.

  • Revised error handling rules for optional transitive BGP attributes
    so that a BGP speaker is no longer required to reset the session
    over which a malformed attribute is received. Provide guidelines
    for authors of documents that define new optional transitive
    attributes, and re-assess procedures for existing optional
    transitive attributes

  • Specify Link Bandwidth Extended Community for use in unequal cost
    load balancing.

  • The definition of an "Accumulated IGP Metric" attribute for BGP
    to report the sum of the metric of each link along the path.
    This attribute is for use in a restricted environment where:

  • all ASes are subject to the administrative control
  • some form of tunneling is used to deliver a packet to its next
    BGP hop
  • where the path for a route leads outside the AS to which the
    BGP speaker adding the attribute belongs.

  • Advertisement of the best external route in BGP to assist with
    resolution of the next hop in the chosen data plane.