Deprecation of AS_SET and AS_CONFED_SET in BGP
draft-kumari-deprecate-as-set-confed-set-14

Document Type Active Internet-Draft (candidate for idr WG)
Last updated 2019-08-16 (latest revision 2019-08-05)
Stream IETF
Intended RFC status (None)
Formats plain text pdf html bibtex
Stream WG state Call For Adoption By WG Issued
Document shepherd No shepherd assigned
IESG IESG state I-D Exists
Consensus Boilerplate Unknown
Telechat date
Responsible AD (None)
Send notices to (None)
Network Working Group                                          W. Kumari
Internet-Draft                                              Google, Inc.
Intended status: Standards Track                               K. Sriram
Expires: February 6, 2020                                       USA NIST
                                                          August 5, 2019

             Deprecation of AS_SET and AS_CONFED_SET in BGP
              draft-kumari-deprecate-as-set-confed-set-14

Abstract

   BCP 172 (i.e., RFC 6472) recommends not using AS_SET and
   AS_CONFED_SET in Border Gateway Protocol (BGP).  This document
   updates RFC 4271 and proscribes the use of the AS_SET and
   AS_CONFED_SET types of path segments in the AS_PATH.  This is done to
   simplify the design and implementation of BGP and to make the
   semantics of the originator of a route clearer.  This will also
   simplify the design, implementation, and deployment of various BGP
   security mechanisms.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on February 6, 2020.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect

Kumari & Sriram         Expires February 6, 2020                [Page 1]
Internet-Draft    AS_SET, AS_CONFED_SET use deprecation      August 2019

   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  Recommendation to Network Operators . . . . . . . . . . . . .   3
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   BCP 172 [RFC6472] makes a recommendation for not using AS_SET and
   AS_CONFED_SET in Border Gateway Protocol (BGP).  This document
   advances the recommendation to a standards requirement in BGP.  It
   updates [RFC4271] and proscribes the use of the AS_SET and
   AS_CONFED_SET types of path segments in the AS_PATH.

   The AS_SET path segment in the AS_PATH attribute (Sections 4.3 and
   5.1.2 of [RFC4271]) is created by a router that is performing route
   aggregation and contains an unordered set of Autonomous Systems
   (ASes) that the update has traversed.  The AS_CONFED_SET path segment
   (see [RFC5065]) in the AS_PATH attribute is created by a router that
   is performing route aggregation and contains an unordered set of
   Member AS Numbers in the local confederation that the update has
   traversed.  It is very similar to AS_SETs but is used within a
   confederation.

   By performing aggregation, a router is combining multiple existing
   routes into a single new route.  The aggregation together with the
   use of AS_SET blurs the semantics of origin AS for the prefix being
   announced.  Therefore, the aggregation with AS_SET (or AS_CONFED_SET)
   can cause operational issues, such as not being able to authenticate
   a route origin for the aggregate prefix in new BGP security
   technologies such as those that take advantage of X.509 extensions
   for IP addresses and AS identifiers [RFC3779] [RFC6811] [RFC8205].
   This in turn could result in reachability problems for the aggregated
   prefix and its components (i.e., more-specific prefixes).  The
   aggregation as described above could also create traffic engineering

Kumari & Sriram         Expires February 6, 2020                [Page 2]
Show full document text