BIER WG                                                       Fangwei Hu
Internet-Draft                                               Greg Mirsky
Intended status: Standards Track                              Quan Xiong
Expires: January 31, 2019                                ZTE Corporation
                                                               Chang Liu
                                                            China Unicom
                                                           July 30, 2018


                                BIER BFD
                        draft-hu-bier-bfd-01.txt

Abstract

   Point to multipoint (P2MP) BFD is designed to verify multipoint
   connectivity.  This document specifies the support of P2MP BFD in
   BIER network.

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   This Internet-Draft will expire on January 31, 2019.

Copyright Notice

   Copyright (c) 2018 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   include Simplified BSD License text as described in Section 4.e of




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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   2
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   3.  BIER BFD Encapsulation  . . . . . . . . . . . . . . . . . . .   3
   4.  Bootstrapping BIER BFD  . . . . . . . . . . . . . . . . . . .   3
     4.1.  One-hop Bootstrapping . . . . . . . . . . . . . . . . . .   3
     4.2.  Multi-hop Bootstrapping . . . . . . . . . . . . . . . . .   4
   5.  Discriminators and Packet Demultiplexing  . . . . . . . . . .   4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   Bit Index Explicit Replication(BIER)[RFC8279] provides optimal
   forwarding of multicast data packets through a multicast domain.  It
   does so without requiring any explicit tree-building protocol and
   without requiring intermediate nodes to maintain any per-flow state.

   [I-D.ietf-bfd-multipoint] defines a method of using Bidirectional
   Detection(BFD) to monitor and detect unicast failures between the
   sender (head) and one or more receivers (tails) in multipoint or
   multicast networks.

   This document describes the procedures for using such mode of BFD
   protocol to verify multipoint or multicast connectivity between a
   multipoint sender (the "head", Bit-Forwarding Ingress Routers(BFIRs))
   and a set of one or more multipoint receivers (the"tails", Bit-
   Forwarding Egress Routers(BFERs)).  The BIER BFD only supports the
   unidirectional multicast.  This document defines use of the point-to-
   multipoint BFD for BIER domain.

2.  Conventions used in this document








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2.1.  Terminology

   This document uses the acronyms defined in [RFC8279] along with the
   following:

   BFD: Bidirectional Forwarding Detection.

   NLPID: Network Layer Protocol Identifier.

   OAM: Operations, Administration, and Maintenance.

   P2MP: Point to Multi-Point.

2.2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  BIER BFD Encapsulation

   BIER BFD encapsulation uses the BIER OAM packet format defined in
   [I-D.ietf-bier-ping].  If the Msg type field is 3(TBD, it is assigned
   by IANA), it indicates that the OAM packet is BIER BFD packet.

   The message type of OAM packet is defined as the following:

                   +-------+----------+---------------+
                   |  Type |  Value   |   Reference   |
                   +-------+----------+---------------+
                   |   3   | BIER BFD | This document |
                   +-------+----------+---------------+

                                  Table 1

4.  Bootstrapping BIER BFD

4.1.  One-hop Bootstrapping

   The ISIS BFD-Enable TLV is defined in [RFC6213], which could be used
   for BIER BFD bootstrapping if the underlay routing protocol is ISIS
   routing protocol.  When the adjacency between BIER nodes reaches the
   2-Way state, ISIS Hellos will already have been exchanged.  If an
   BIER node supports BFD, it will have learned whether the other BIER
   node has BFD enabled by whether or not a BFD-Enabled TLV was included
   in its Hellos.  The BFD-Enable TLV format is defined in [RFC6213] and



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   reused in this document.  The MT ID is the BIER multi-topology
   identify.  If the BIER node only supports single ISIS topology, the
   MT ID is zero.  The NLPIDs encoded in the TLV are defined in
   [ISO9577].

4.2.  Multi-hop Bootstrapping

   The BIER OAM ping could be used for BIER BFD bootstrap.  The
   multipoint header sends the BIER OAM packet with Target SI-Bitstring
   TLV (section 3.3.2 of [I-D.ietf-bier-ping]) carrying the set of BFER
   information (Sub-domain-id, Set ID, BS Len, Bitstring) to the
   multipoint tails to bootstrap the BIER BFD sessions.

5.  Discriminators and Packet Demultiplexing

   The tail(BFER) demultiplexes incoming BFD packets based on a
   combination of the source address and My discriminator as specified
   in [I-D.ietf-bfd-multipoint].  The source address is BFIR-id and BIER
   MPLS Label(MPLS network) or BFIR-id and BIFT-id(Non-MPLS network)for
   BIER BFD.

6.  Security Considerations

   For BIER OAM packet procssing security considerations, see
   [I-D.ietf-bier-ping].

   For general multipoint BFD security considerations, see
   [I-D.ietf-bfd-multipoint].

   No additional security issues are raised in this document beyond
   those that exist in the referenced BFD documents.

7.  Acknowledgements

   Authors would like to thank the comments and suggestions from Jeffrey
   (Zhaohui) Zhang, Donald Eastlake 3rd.

8.  IANA Considerations

   IANA is requested to assign new type from the BIER OAM Message Type
   registry as follows:










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               +--------+--------------+------------------+
               | Value  | Description  |    Reference     |
               +--------+--------------+------------------+
               |  TBD   |   BIER BFD   | [this document]  |
               +--------+--------------+------------------+

                                  Table 2

9.  References

9.1.  Normative References

   [I-D.ietf-bfd-multipoint]
              Katz, D., Ward, D., Networks, J., and G. Mirsky, "BFD for
              Multipoint Networks", draft-ietf-bfd-multipoint-18 (work
              in progress), June 2018.

   [I-D.ietf-bier-ping]
              Kumar, N., Pignataro, C., Akiya, N., Zheng, L., Chen, M.,
              and G. Mirsky, "BIER Ping and Trace", draft-ietf-bier-
              ping-03 (work in progress), January 2018.

   [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>.

   [RFC6213]  Hopps, C. and L. Ginsberg, "IS-IS BFD-Enabled TLV",
              RFC 6213, DOI 10.17487/RFC6213, April 2011,
              <https://www.rfc-editor.org/info/rfc6213>.

   [RFC6328]  Eastlake 3rd, D., "IANA Considerations for Network Layer
              Protocol Identifiers", BCP 164, RFC 6328,
              DOI 10.17487/RFC6328, July 2011,
              <https://www.rfc-editor.org/info/rfc6328>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8279]  Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
              Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
              Explicit Replication (BIER)", RFC 8279,
              DOI 10.17487/RFC8279, November 2017,
              <https://www.rfc-editor.org/info/rfc8279>.






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9.2.  Informative References

   [ISO9577]  ISO/IEC TR 9577:1999,, "International Organization for
              Standardization "Information technology -
              Telecommunications and Information exchange between
              systems - Protocol identification in the network layer"",
              1999.

Authors' Addresses

   Fangwei Hu
   ZTE Corporation
   No.889 Bibo Rd
   Shanghai  201203
   China

   Phone: +86 21 68896273
   Email: hu.fangwei@zte.com.cn


   Greg Mirsky
   ZTE Corporation
   USA

   Email: gregimirsky@gmail.com


   Quan Xiong
   ZTE Corporation
   No.6 Huashi Park Rd
   Wuhan, Hubei  430223
   China

   Phone: +86 27 83531060
   Email: xiong.quan@zte.com.cn


   Chang Liu
   China Unicom
   No.9 Shouti Nanlu
   Beijing   100048
   China

   Phone: +86-010-68799999-7294
   Email: liuc131@chinaunicom.cn






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