BIER WG Quan Xiong Internet-Draft Greg Mirsky Intended status: Standards Track Fangwei Hu Expires: September 2, 2019 ZTE Corporation Chang Liu China Unicom March 1, 2019 BIER BFD draft-hu-bier-bfd-03.txt Abstract Point to multipoint (P2MP) BFD is designed to verify multipoint connectivity. This document specifies the application of P2MP BFD in BIER network. 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 September 2, 2019. 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 Quan Xiong, et al. Expires September 2, 2019 [Page 1] Internet-Draft BIER BFD March 2019 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 . . . . . . . . . . . . . . 3 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 3. BIER BFD Encapsulation . . . . . . . . . . . . . . . . . . . 3 4. Bootstrapping BIER BFD . . . . . . . . . . . . . . . . . . . 3 4.1. BIER OAM Ping Bootstrap . . . . . . . . . . . . . . . . . 3 4.2. IGP protocol Bootstrap . . . . . . . . . . . . . . . . . 4 4.2.1. IS-IS extension for BIER BFD . . . . . . . . . . . . 4 4.2.2. OSPF extension for BIER BFD . . . . . . . . . . . . . 5 5. Discriminators and Packet Demultiplexing . . . . . . . . . . 5 6. Active Tail in BIER BFD . . . . . . . . . . . . . . . . . . . 5 7. Security Considerations . . . . . . . . . . . . . . . . . . . 6 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 10.1. Normative References . . . . . . . . . . . . . . . . . . 6 10.2. Informative References . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 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. BIER resilience use cases are described in [I-D.xiong-bier-resilience] including End-to-End 1+1 and 1:1 Protection and the failure detection mechanisms MAY use P2MP BFD and P2MP active tail detection method respectively. [I-D.ietf-bfd-multipoint] defines a method of using Bidirectional Forwarding Detection(BFD) to monitor and detect unicast failures between the sender (head) and one or more receivers (tails) in multipoint or multicast networks. [I-D.ietf-bfd-multipoint-active-tail] describes active tail extensions to the BFD protocol for multipoint 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 Quan Xiong, et al. Expires September 2, 2019 [Page 2] Internet-Draft BIER BFD March 2019 unidirectional multicast. This document defines the use of P2MP BFD as per [I-D.ietf-bfd-multipoint], and active tail as per [I-D.ietf-bfd-multipoint-active-tail] for BIER-specific domain. 2. Conventions used in this document 2.1. Terminology This document uses the acronyms defined in [RFC8279] along with the following: BFD: Bidirectional Forwarding Detection. 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]. The value of the Msg Type field MUST be set to BIER BFD (TBD1 by IANA ). BFD Control packet, defined in Section 4 [RFC5880] immediately follows the BIER OAM header. 4. Bootstrapping BIER BFD 4.1. BIER OAM Ping Bootstrap The BIER OAM ping could be used for BIER BFD bootstrap. The BFIR sends the BIER OAM ping Echo request messages carring a BFD discriminator TLV which immediately follows the Target SI-Bitstring TLV (section 3.3.2 [I-D.ietf-bier-ping]) which MUST be included to carry the set of BFER information (Sub-domain-id, Set ID, BS Len, Bitstring) for the purpose of session establishment. The BFD discriminator TLV is a new TLV for BIER OAM TLV with the type (TBD2 by IANA) and the length of 4. The value contains the 4-byte local discriminator generated by BFIR for this session. Quan Xiong, et al. Expires September 2, 2019 [Page 3] Internet-Draft BIER BFD March 2019 4.2. IGP protocol Bootstrap An alternative option to bootstrap the BIER BFD is to advertise the BFD information IGP protocol in control plane. This document defines a new BIER BFD Sub-TLV carried in IS-IS and OSPF capaibility to advertise My Discriminator for BFIR. 4.2.1. IS-IS extension for BIER BFD The new BIER BFD Sub-TLV is carried in the ISIS router capaiblity TLV. The format is 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | My Discriminator | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | RESERVED | BIFT-id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BitString (first 32 bits) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ BitString (last 32 bits) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: BIER BFD Sub-TLV for IS-IS extension Type : TBD3 by IANA. Length : Length of the BIER BFD Sub-TLV for IS-IS extension, in bytes. My Discriminator : A unique, nonzero discriminator value generated by BFIR for each multipoint path. The BitString field carries the set of BFR-IDs of BFER(s) that the BFIR expects to establish BIER BFD session. The BIFT-id represents a particular Bit Index Forwarding Table (BIFT) as per [RFC8279]. Quan Xiong, et al. Expires September 2, 2019 [Page 4] Internet-Draft BIER BFD March 2019 4.2.2. OSPF extension for BIER BFD The new BIER BFD Sub-TLV is carried in the Router Information Link State Advertisement (LSA). The format is 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | My Discriminator | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | RESERVED | BIFT-id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BitString (first 32 bits) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ BitString (last 32 bits) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: BIER BFD Sub-TLV for OSPF extension Type : TBD4 by IANA. Length : Length of the BIER BFD Sub-TLV for OSPF extension, in bytes. Other fields in BIER BFD Sub-TLV is the same with section 4.2.1. 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. Active Tail in BIER BFD [I-D.ietf-bfd-multipoint-active-tail] defined an extension for Multipoint BFD, which allows tails to notify the head of the lack of multipoint connectivity. For BIER BFD in active tail mode, the BFIR may learn the state and connectivity of the BFERs. As per [I-D.ietf-bfd-multipoint-active-tail], the BFIR can send the Poll sequence messages in combination with the unicast BFD over the monitored BFERs. Quan Xiong, et al. Expires September 2, 2019 [Page 5] Internet-Draft BIER BFD March 2019 7. 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. 8. Acknowledgements Authors would like to thank the comments and suggestions from Jeffrey (Zhaohui) Zhang, Donald Eastlake 3rd. 9. IANA Considerations IANA is requested to assign new type from the BIER OAM Message Type registry as follows: +--------+-----------------------------+------------------+ | Value | Description | Reference | +--------+-----------------------------+------------------+ | TBD1 | BIER BFD | [this document] | | TBD2 | BFD discriminator TLV | [this document] | | TBD3 | BIER BFD Sub-TLV for IS-IS | [this document] | | TBD4 | BIER BFD Sub-TLV for OSPF | [this document] | +--------+-----------------------------+------------------+ Table 1 10. References 10.1. Normative References [I-D.ietf-bfd-multipoint] Katz, D., Ward, D., Networks, J., and G. Mirsky, "BFD for Multipoint Networks", draft-ietf-bfd-multipoint-19 (work in progress), December 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-04 (work in progress), October 2018. Quan Xiong, et al. Expires September 2, 2019 [Page 6] Internet-Draft BIER BFD March 2019 [I-D.xiong-bier-resilience] Xiong, Q., hu, f., and G. Mirsky, "The Resilience for BIER", draft-xiong-bier-resilience-01 (work in progress), October 2018. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, . [RFC6213] Hopps, C. and L. Ginsberg, "IS-IS BFD-Enabled TLV", RFC 6213, DOI 10.17487/RFC6213, April 2011, . [RFC6328] Eastlake 3rd, D., "IANA Considerations for Network Layer Protocol Identifiers", BCP 164, RFC 6328, DOI 10.17487/RFC6328, July 2011, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [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, . 10.2. Informative References [I-D.ietf-bfd-multipoint-active-tail] Katz, D., Ward, D., Networks, J., and G. Mirsky, "BFD Multipoint Active Tails.", draft-ietf-bfd-multipoint- active-tail-10 (work in progress), November 2018. [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. Quan Xiong, et al. Expires September 2, 2019 [Page 7] Internet-Draft BIER BFD March 2019 Authors' Addresses Quan Xiong ZTE Corporation No.6 Huashi Park Rd Wuhan, Hubei 430223 China Phone: +86 27 83531060 Email: xiong.quan@zte.com.cn Greg Mirsky ZTE Corporation USA Email: gregimirsky@gmail.com Fangwei Hu ZTE Corporation No.889 Bibo Rd Shanghai 201203 China Phone: +86 21 68896273 Email: hu.fangwei@zte.com.cn Chang Liu China Unicom No.9 Shouti Nanlu Beijing 100048 China Phone: +86-010-68799999-7294 Email: liuc131@chinaunicom.cn Quan Xiong, et al. Expires September 2, 2019 [Page 8]