[Docs] [txt|pdf|xml|html] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-heitz-idr-large-community) 00 01 02 03 04 05 06 07 08 09 10 11 12 RFC 8092

IDR                                                             J. Heitz
Internet-Draft                                                     Cisco
Intended status: Standards Track                                K. Patel
Expires: April 11, 2017                                           Arrcus
                                                             J. Snijders
                                                                     NTT
                                                             I. Bagdonas
                                                                 Equinix
                                                              A. Simpson
                                                                   Nokia
                                                         October 8, 2016


                         Large BGP Communities
                   draft-ietf-idr-large-community-02

Abstract

   This document describes the Large BGP Community attribute, an
   extension to BGP-4.  This attribute provides a mechanism to signal
   opaque information within separate namespaces to aid in routing
   management.  The attribute is suitable for use in 4-octet ASNs.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

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 http://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 April 11, 2017.






Heitz, et al.            Expires April 11, 2017                 [Page 1]


Internet-Draft            Large BGP Communities             October 2016


Copyright Notice

   Copyright (c) 2016 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
   (http://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
   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.  Large BGP Communities Attribute . . . . . . . . . . . . . . .   3
   3.  Aggregation . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Textual Representation  . . . . . . . . . . . . . . . . . . .   4
   5.  Reserved Large BGP Community values . . . . . . . . . . . . .   4
   6.  Error Handling  . . . . . . . . . . . . . . . . . . . . . . .   5
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   8.  Implementation status - RFC EDITOR: REMOVE BEFORE PUBLICATION   5
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   6
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     11.1.  Normative References . . . . . . . . . . . . . . . . . .   7
     11.2.  Informative References . . . . . . . . . . . . . . . . .   7
     11.3.  URIs . . . . . . . . . . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   BGP implementations typically support a routing policy language to
   control the distribution of routing information.  Network operators
   attach BGP communities to routes to identify intrinsic properties of
   these routes.  These properties may include information such as the
   route origin location, or specification of a routing policy action to
   be taken, or one that has been taken, and may apply to an individual
   route or to a group of routes.  Because BGP communities are optional
   transitive BGP attributes, BGP communities may be acted upon or
   otherwise used by routing policies in other Autonomous Systems (ASes)
   on the Internet.

   [RFC1997] BGP Communities Attributes are four-octet values split into
   two individual two-octet words.  The most significant word is usually



Heitz, et al.            Expires April 11, 2017                 [Page 2]


Internet-Draft            Large BGP Communities             October 2016


   interpreted as an Autonomous System Number (ASN) and the least
   significant word is a locally defined value whose meaning is assigned
   by the operator of the Autonomous System in the most significant
   word.

   Since the adoption of four-octet ASNs [RFC6793], the BGP Communities
   Attribute can no longer accommodate this encoding, as the
   specification in [RFC1997] contains only four octets.  This does not
   allow operators to specify any locally significant values.

   To address these shortcomings, this document defines a Large
   Community BGP Attribute encoded as one or more 12-octet values, each
   consisting of a four-octet ASN and two four-octet operator-defined
   values, each of which can be used to denote properties or actions
   significant to that ASN.

2.  Large BGP Communities Attribute

   This document creates the Large Communities BGP path attribute as an
   optional transitive attribute of variable length.  All routes with
   the Large Communities attribute belong to the community specified in
   the attribute.

   The attribute consists of one or more 12-octet values.  Each 12-octet
   Large Communities value represents three 4-octet values, as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Global Administrator                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Local Data Part 1                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Local Data Part 2                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Global Administrator:  A four-octet namespace identifier.  This
      SHOULD be an Autonomous System Number.

   Local Data Part 1:  A four-octet operator-defined value.

   Local Data Part 2:  A four-octet operator-defined value.

   The Global Administrator field is intended to allow different
   Autonomous Systems to define Large Communities without collision.
   Implementations MUST allow the operator to specify any value for the
   Global Administrator field.




Heitz, et al.            Expires April 11, 2017                 [Page 3]


Internet-Draft            Large BGP Communities             October 2016


   There is no significance to the order in which Large Communities are
   encoded in a path attributes field and a receiving speaker MAY
   retransmit them in an order different from which it received them.

   Duplicate Large Communities SHOULD NOT be transmitted.  A receiving
   speaker SHOULD silently remove duplicate Large Communities from a BGP
   UPDATE message.

3.  Aggregation

   If a range of routes is aggregated and the resulting aggregates
   attribute section does not carry the ATOMIC_AGGREGATE attribute, then
   the resulting aggregate should have a Large Communities path
   attribute which contains all of the large communities from all of the
   aggregated routes.

4.  Textual Representation

   BGP Communities [RFC1998] are usually represented in routing policy
   languages as two individual two-octet unsigned integers separated by
   a colon; for example, 64496:12345.

   BGP Large Communities implementations MUST represent Large
   Communities in a manner similar to their representation of BGP
   Communities [RFC1998].  Large Communities MUST be represented as
   three separate four-octet unsigned integers in decimal format with no
   leading zeros.  These integers MUST NOT be omitted, even when zero.
   For example, 64496:4294967295:2 or 64496:0:0.

   Vendors MAY provide other textual representations.  For example, a
   vendor's routing policy language may use a separator other than a
   colon or may require keywords or characters prepending or postpending
   the Large Communities attribute.  Such differences are permitted.
   However, each implementation MUST make a representation available
   that depicts the integers in decimal and in the following order:
   Global Administrator, Local Data Part 1, Local Data Part 2.

5.  Reserved Large BGP Community values

   The Large BGP Community attribute values in the following ranges are
   reserved:

            0:0:0 -          0:4294967295:4294967295
        65535:0:0 -      65535:4294967295:4294967295
   4294967295:0:0 - 4294967295:4294967295:4294967295






Heitz, et al.            Expires April 11, 2017                 [Page 4]


Internet-Draft            Large BGP Communities             October 2016


6.  Error Handling

   The error handling of Large Communities is as follows:

   o  A Large Communities BGP Path Attribute with a length of zero MUST
      be ignored upon receipt and removed when sending.

   o  A Large Communities attribute SHALL be considered malformed if its
      length is not a non-zero multiple of 12 bytes.

   o  A BGP UPDATE message with a malformed Large Communities attribute
      SHALL be handled using the approach of "treat-as-withdraw" as
      described in section 2 [RFC7606].

   The BGP Large Communities Global Administrator field may contain any
   value, and a Large Communities attribute MUST NOT be considered
   malformed if the Global Administrator field contains an unallocated,
   unassigned or reserved ASN or is set to one of the reserved Large BGP
   Community values defined in Section 5.

7.  Security Considerations

   This extension to BGP has similar security implications as BGP
   Communities [RFC1997].

   This document does not change any underlying security issues
   associated with any other BGP Communities mechanism.  Specifically,
   an AS relying on the Large BGP Community attribute carried in BGP
   must have trust in every other AS in the path, as any intermediate
   Autonomous System in the path may have added, deleted or altered the
   Large BGP Community attribute.  Specifying the mechanism to provide
   such trust is beyond the scope of this document.

   Network administrators should note the recommendations in Section 11
   of BGP Operations and Security [RFC7454].

8.  Implementation status - RFC EDITOR: REMOVE BEFORE PUBLICATION

   This section records the status of known implementations of the
   protocol defined by this specification at the time of posting of this
   Internet-Draft, and is based on a proposal described in [RFC7942].
   The description of implementations in this section is intended to
   assist the IETF in its decision processes in progressing drafts to
   RFCs.  Please note that the listing of any individual implementation
   here does not imply endorsement by the IETF.  Furthermore, no effort
   has been spent to verify the information presented here that was
   supplied by IETF contributors.  This is not intended as, and must not
   be construed to be, a catalog of available implementations or their



Heitz, et al.            Expires April 11, 2017                 [Page 5]


Internet-Draft            Large BGP Communities             October 2016


   features.  Readers are advised to note that other implementations may
   exist.

   As of today these vendors have produced an implementation of Large
   BGP Community:

   o  Cisco IOS XR

   o  ExaBGP

   o  GoBGP

   o  BIRD

   o  OpenBGPD

   The latest implementation news is tracked at
   http://largebgpcommunities.net/ [1].

9.  IANA Considerations

   IANA has made an Early Allocation of the value 30 (LARGE_COMMUNITY)
   in the "BGP Path Attributes" registry under the "Border Gateway
   Protocol (BGP) Parameters" group and is now asked to make that
   Permanent.

10.  Acknowledgments

   The authors would like to thank Ruediger Volk, Russ White, Acee
   Lindem, Shyam Sethuram, Jared Mauch, Joel M.  Halpern, Nick Hilliard,
   Jeffrey Haas, John Heasley, Gunter van de Velde, Marco Marzetti,
   Eduardo Ascenco Reis, Mark Schouten, Paul Hoogsteder, Martijn
   Schmidt, Greg Hankins, Acee Lindem, Bertrand Duvivier, Barry
   O'Donovan, Grzegorz Janoszka, Linda Dunbar, Marco Davids, Gaurab Raj
   Upadhaya, Jeff Tantsura, Teun Vink, Adam Davenport, Theodore Baschak,
   Pier Carlo Chiodi, Nabeel Cocker, Ian Dickinson, Jan Baggen, Duncan
   Lockwood, David Farmer, Randy Bush, Wim Henderickx, Stefan Plug, Kay
   Rechthien, Rob Shakir, Warren Kumari, Gert Doering, Thomas King,
   Mikael Abrahamsson, Wesley Steehouwer, Sander Steffann, Brad
   Dreisbach, Martin Millnert, Christopher Morrow, Jay Borkenhagen,
   Arnold Nipper, Joe Provo, Niels Bakker, Bill Fenner, Tom Daly, Ben
   Maddison, Alexander Azimov, Brian Dickson, Peter van Dijk, Julian
   Seifert, Tom Petch and Tom Scholl for their support, insightful
   review and comments.







Heitz, et al.            Expires April 11, 2017                 [Page 6]


Internet-Draft            Large BGP Communities             October 2016


11.  References

11.1.  Normative References

   [RFC1997]  Chandra, R., Traina, P., and T. Li, "BGP Communities
              Attribute", RFC 1997, DOI 10.17487/RFC1997, August 1996,
              <http://www.rfc-editor.org/info/rfc1997>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC6793]  Vohra, Q. and E. Chen, "BGP Support for Four-Octet
              Autonomous System (AS) Number Space", RFC 6793,
              DOI 10.17487/RFC6793, December 2012,
              <http://www.rfc-editor.org/info/rfc6793>.

   [RFC7606]  Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
              Patel, "Revised Error Handling for BGP UPDATE Messages",
              RFC 7606, DOI 10.17487/RFC7606, August 2015,
              <http://www.rfc-editor.org/info/rfc7606>.

11.2.  Informative References

   [RFC1998]  Chen, E. and T. Bates, "An Application of the BGP
              Community Attribute in Multi-home Routing", RFC 1998,
              DOI 10.17487/RFC1998, August 1996,
              <http://www.rfc-editor.org/info/rfc1998>.

   [RFC7454]  Durand, J., Pepelnjak, I., and G. Doering, "BGP Operations
              and Security", BCP 194, RFC 7454, DOI 10.17487/RFC7454,
              February 2015, <http://www.rfc-editor.org/info/rfc7454>.

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <http://www.rfc-editor.org/info/rfc7942>.

11.3.  URIs

   [1] https://largebgpcommunities.net

Authors' Addresses







Heitz, et al.            Expires April 11, 2017                 [Page 7]


Internet-Draft            Large BGP Communities             October 2016


   Jakob Heitz
   Cisco
   170 West Tasman Drive
   San Jose, CA  95054
   USA

   Email: jheitz@cisco.com


   Keyur Patel
   Arrcus, Inc

   Email: keyur@arrcus.com


   Job Snijders
   NTT Communications
   Theodorus Majofskistraat 100
   Amsterdam  1065 SZ
   NL

   Email: job@ntt.net


   Ignas Bagdonas
   Equinix
   London
   UK

   Email: ibagdona.ietf@gmail.com


   Adam Simpson
   Nokia
   600 March Road
   Ottawa  Ontario K2K 2E6
   Canada

   Email: adam.1.simpson@nokia.com












Heitz, et al.            Expires April 11, 2017                 [Page 8]


Html markup produced by rfcmarkup 1.124, available from https://tools.ietf.org/tools/rfcmarkup/