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.
Status of This Memo
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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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