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Versions: 00 01

Network Working Group                                            J. Dong
Internet-Draft                                                 S. Zhuang
Intended status: Standards Track                     Huawei Technologies
Expires: January 9, 2020                                 G. Van de Velde
                                                                   Nokia
                                                            July 8, 2019


         BGP Extended Community for Identifying the Target Node
                 draft-dong-idr-node-target-ext-comm-01

Abstract

   BGP has been used to distribute different types of routing and policy
   information in the network.  In some cases, the information
   distributed may be only intended for one or several particular
   receiving BGP nodes in the network.  However, BGP does not have a
   general mechanism for designating the receiving node of the routing
   information.  This document defines a new type of BGP extended
   community called "Node Target".  The mechanism of using the Node
   Target extended community to steer BGP route distribution to
   particular BGP nodes is specified.

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 RFC 2119 [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 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 January 9, 2020.






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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
   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.  Node Target Extended Communities  . . . . . . . . . . . . . .   3
     2.1.  IPv4 Node Target Extended Community . . . . . . . . . . .   3
     2.2.  IPv6 Node Target Extended Community . . . . . . . . . . .   4
   3.  Procedures  . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   6
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   BGP [RFC4271] has been used to distribute different types of routing
   and policy information in the network.  In some cases, the
   information distributed may be only intended for one or several
   particular receiving BGP nodes in the network.  A typical use case is
   the distribution of BGP FlowSpec [RFC5575] [I-D.ietf-idr-rfc5575bis]
   policies to some particular BGP nodes.

   However, BGP does not have a general mechanism for designating the
   receiving nodes of the information to be distributed.  Route Target
   (RT) as defined in [RFC4364] is used for the distribution of VPN
   routes into the target VPN Routing and Forwarding tables (VRFs) on a
   set of PE nodes.  Although it is possible to use RTs to control the
   distribution of non VPN-specific information to a particular node,
   such mechanism is not applicable when the information to be
   distributed is VPN-specific and relies on RTs to match the target




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   VRF.  Thus a mechanism which is independent from the control of VPN
   route to VRF distribution is needed.

   Another possible way is to configure, on each router, a community and
   the corresponding policies to match the community to determine
   whether to accept the received routes.  Such mechanism relies on
   manual configuration thus is considered error-prone.  It is
   preferable by operators that an automatic approach can be provided.

   This document defines a new type of BGP extended community called
   "Node Target".  The mechanism of using the Node Target extended
   community to steer BGP route distribution to particular BGP nodes is
   also specified.

2.  Node Target Extended Communities

2.1.  IPv4 Node Target Extended Community

   For IPv4 networks, this section defines a new BGP extended community
   [RFC4360] called "IPv4 Node Target Extended Community".  It is a
   transitive extended community with type 0x01 and sub-type TBA.

   The format of IPv4 Node Target Extended Community is shown in
   Figure 1.

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Type (0x01)  | Sub-Type (TBA)|     Target IPv4 Address       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Target IPv4 Address (cont.)  |           Reserved            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
               Figure 1. IPv4 Node Target extended community

   Target IPv4 address field: A local IPv4 address of the target node.
   When the target IPv4 address is set to 0.0.0.0, it means all the BGP
   nodes in the network are the target nodes.

   Reserved field: Reserved for future use, MUST be set to zero on
   transmission and ignored on receipt.

   One or more IPv4 Node Target extended communities may be carried in a
   BGP Update message.








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2.2.  IPv6 Node Target Extended Community

   For IPv6 networks, a new IPv6 Address Specific BGP Extended Community
   [RFC5701] called "IPv6 Node Target extended community" is defined.
   It is a transitive IPv6 address specific extended community with type
   0x00 and sub-type TBA.

   The format of this extended community is shown in Figure 2.

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Type (0x00)  | Sub-Type (TBA)|    Target IPv6 Address        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |           Target IPv6 Address (cont.)                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |           Target IPv6 Address (cont.)                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |           Target IPv6 Address (cont.)                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Target IPv6 Address (cont.)  |           Reserved            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
               Figure 2. IPv6 Node Target extended community

   Target IPv6 address field: A IPv6 address of the target node.  When
   the target IPv6 address is set to "0:0:0:0:0:0:0:0" ( :: ), it means
   all the BGP nodes in the network are the target nodes.

   Reserved field: Reserved for future use, MUST be set to zero on
   transmission and ignored on receipt.

   One or more IPv6 Node Target extended communities may be carried in a
   BGP Update message.

3.  Procedures

   In this version only the usage of the proposed mechanism in the
   intra-AS scenario is described, more details about the inter-AS
   scenario is for further study.

   When a controller or BGP speaker plans to advertise some BGP
   information only to some particular BGP nodes in the network, it MUST
   put the IPv4 or IPv6 address of each target node into the IPv4 or
   IPv6 Node Target extended communities, and attach the IPv4 or IPv6
   Node Target extended communities to the BGP Update message to be
   advertised.





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   If a non-RR BGP speaker receives an Update message which contains one
   or more IPv4 or IPv6 Node Target extended communities, it MUST check
   the target IPv4 or IPv6 addresses carried in the extended
   communities.

   o  If the target IPv4 or IPv6 address in any of the IPv4 or IPv6 Node
      Target extended community matches with one of the local IP
      addresses, the receiving BGP speaker is one of the target nodes of
      the information in the Update, and the information in the Update
      is eligible to be kept and installed by the receiving BGP speaker.

   o  If the target IPv4 or IPv6 address in any of the IPv4 or IPv6 Node
      Target extended community does not match with any local IP
      address, the receiving BGP speaker is not the target node of
      information in the Update, the information in the received Update
      message MUST not be used.

   If a route-reflector (RR) receives an BGP Update message which
   contains one or more IPv4 or IPv6 Node Target extended communities,
   it MUST check the target IPv4 or IPv6 addresses carried in the IPv4
   or IPv6 Node Target extended communities.

   o  If the target IPv4 or IPv6 address in any of the IPv4 or IPv6 Node
      Target extended community matches with one of the local IP
      addresses, this RR is one of the target nodes of information in
      the Update, and such information is eligible to be kept and
      installed by this RR.  If there is no other IPv4 or IPv6 Node
      Target extended communities in the Update, the RR MUST NOT
      advertise the information in this Update further to its neighbors.
      If there is other IPv4 or IPv6 Node Target extended communities,
      the RR SHOULD first remove the local matched Node Target extended
      community, then reflect the routes with the remaining Node Target
      Extended Communities according to [RFC4456].

   o  If the target IPv4 or IPv6 address in any of the IPv4 or IPv6 Node
      target extended community does not match with any local IP
      address, this RR is not the target node of routes in the Update,
      the rules defined in [RFC4456] are used for the reflection of the
      received route.

4.  IANA Considerations

   This document requests that IANA assigns one new sub-type for "IPv4
   Node Target extended community" from the "Transitive IPv4-Address-
   Specific Extended Community" registry of the "BGP extended
   communities" registry.





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   This document requests that IANA assigns one new type for "IPv6 Node
   Target extended community" from the "Transitive IPv6-Address-Specific
   Extended Community" registry of the "BGP extended communities"
   registry.

5.  Security Considerations

   This document does not change the security properties of BGP.

6.  Acknowledgements

   The authors would like to thank Zhenbin Li and Ercin Torun for the
   discussion and review of this document.

7.  References

7.1.  Normative References

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

   [RFC4271]  Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
              Border Gateway Protocol 4 (BGP-4)", RFC 4271,
              DOI 10.17487/RFC4271, January 2006,
              <https://www.rfc-editor.org/info/rfc4271>.

   [RFC4360]  Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
              Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
              February 2006, <https://www.rfc-editor.org/info/rfc4360>.

   [RFC4456]  Bates, T., Chen, E., and R. Chandra, "BGP Route
              Reflection: An Alternative to Full Mesh Internal BGP
              (IBGP)", RFC 4456, DOI 10.17487/RFC4456, April 2006,
              <https://www.rfc-editor.org/info/rfc4456>.

   [RFC5701]  Rekhter, Y., "IPv6 Address Specific BGP Extended Community
              Attribute", RFC 5701, DOI 10.17487/RFC5701, November 2009,
              <https://www.rfc-editor.org/info/rfc5701>.

7.2.  Informative References

   [I-D.ietf-idr-rfc5575bis]
              Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M.
              Bacher, "Dissemination of Flow Specification Rules",
              draft-ietf-idr-rfc5575bis-17 (work in progress), June
              2019.



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   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
              2006, <https://www.rfc-editor.org/info/rfc4364>.

   [RFC5575]  Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
              and D. McPherson, "Dissemination of Flow Specification
              Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
              <https://www.rfc-editor.org/info/rfc5575>.

Authors' Addresses

   Jie Dong
   Huawei Technologies
   Huawei Campus, No. 156 Beiqing Rd.
   Beijing  100095
   China

   Email: jie.dong@huawei.com


   Shunwan Zhuang
   Huawei Technologies
   Huawei Campus, No. 156 Beiqing Rd.
   Beijing  100095
   China

   Email: zhuangshunwan@huawei.com


   Gunter Van de Velde
   Nokia
   Antwerp
   BE

   Email: gunter.van_de_velde@nokia.com
















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