MPLS Working Group G. Mirsky Internet-Draft ZTE Corp. Intended status: Standards Track April 21, 2017 Expires: October 23, 2017 BFD for Multipoint Networks over Point-to-Multi-Point MPLS LSP draft-mirsky-mpls-p2mp-bfd-00 Abstract This document describes procedures for using Bidirectional Forwarding Detection (BFD) for multipoint networks to detect data plane failures in Multiprotocol Label Switching (MPLS) point-to-multipoint (p2mp) Label Switched Paths (LSPs). It also describes applicability of out- band solutions to bootstrap a BFD session in this environment. 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/. 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Mirsky Expires October 23, 2017 [Page 1] Internet-Draft Multi-Point BFD over P2MP MPLS LSP April 2017 Table of Contents 1. Conventions used in this document . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 2 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Multipoint BFD Encapsulation . . . . . . . . . . . . . . . . 3 3.1. IP Encapsulation of Multipoint BFD . . . . . . . . . . . 3 3.2. Non-IP Encapsulation of Multipoint BFD . . . . . . . . . 3 4. Bootstrapping Multipoint BFD . . . . . . . . . . . . . . . . 4 4.1. LSP Ping . . . . . . . . . . . . . . . . . . . . . . . . 4 4.2. Control Plane . . . . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 5.1. Source MEP ID IP Address Type . . . . . . . . . . . . . . 4 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 8. Normative References . . . . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 1. Conventions used in this document 1.1. Terminology MPLS: Multiprotocol Label Switching LSP: Label Switched Path BFD: Bidirectional Forwarding Detection p2mp: Point-to-Multipoint FEC: Forwarding Equivalence Class G-ACh: Generic Associated Channel ACH: Associated Channel Header GAL: G-ACh Label 1.2. 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]. Mirsky Expires October 23, 2017 [Page 2] Internet-Draft Multi-Point BFD over P2MP MPLS LSP April 2017 2. Introduction [I-D.ietf-bfd-multipoint] defines a method of using Bidirectional Detection (BFD) [RFC5880] to monitor and detect unicast failures between the sender (head) and one or more receivers (tails) in multipoint or multicast networks. This document describes procedures for using such mode of BFD protocol to detect data plane failures in Multiprotocol Label Switching (MPLS) point-to-multipoint (p2mp) Label Switched Paths (LSPs). The document also describes applicability of out-band solutions to bootstrap a BFD session in this environment. 3. Multipoint BFD Encapsulation [I-D.ietf-bfd-multipoint] defines the tail of multipoint BFD session demultiplexes received BFD control packet based not on Your Discriminator, as defined in [RFC5880], but using source IP address, My Discriminator and the identity of the multipoint tree which the Multipoint BFD Control packet was received from. The identity of the multipoint tree MAY be provided by the p2mp MPLS LSP label in case of inclusive p-tree or upstream assigned label in case of aggregate p-tree. 3.1. IP Encapsulation of Multipoint BFD IP/UDP encapsulation for multipoint BFD over p2mp MPLS LSP follows the same rules as defined in Section 7 [RFC5884] for BFD over p2p LSP: UDP destination port MUST be set to 3784; destination IP address MUST be from the 127/8 range for IPv4 and from the 0:0:0:0:0:FFFF:7F00/104 range for IPv6; if multiple alternative paths for the given p2mp LSP Forwarding Equivalence Class(FEC) exist, the MultipointHead SHOULD use Entropy Label [RFC6790] used for LSP Ping [RFC8029] to excercise that particular alternative path; or the MultipointHead MAY use, as destination IP address, the IP address discovered by LSP Ping traceroute [RFC8029] to exercise that particular alternate path. 3.2. Non-IP Encapsulation of Multipoint BFD Non-IP encapsulation for multipoint BFD over p2mp MPLS LSP MUST use Generic Associated Channel (G-ACh) Label (GAL) [RFC5586] at the bottom of the label stack followed by Associated Channel Header (ACH). Channel Type field in ACH MUST be set to BFD CV [RFC6428]. Mirsky Expires October 23, 2017 [Page 3] Internet-Draft Multi-Point BFD over P2MP MPLS LSP April 2017 To provide identity of the MultipointHead for the particular multipoint BFD session this document defines new Source MEP ID type TBA1 Section 5.1 IP Address. If the Legnth value is 4, then the Value field contains IPv4 address. If the Length value is 16, then the Value field contains IPv6 address. Any other value of the Length field MUST be considered as error and the BFD control packet MUST be discarded. 4. Bootstrapping Multipoint BFD 4.1. LSP Ping MaultipointHead MAY use LSP Ping [RFC8029] using in Target FEC TLV, as appropriate, sub-TLVs defined in Section 3.1 [RFC6425]. 4.2. Control Plane BGP-BFD Attribute [I-D.ietf-bess-mvpn-fast-failover] MAY be used to bootstrap multipoint BFD session on a tail. 5. IANA Considerations 5.1. Source MEP ID IP Address Type IANA is required to allocate value (TBD) for the Source Source MEP ID IP Address type from the "CC/CV MEP-ID TLV" registry which is under the "Pseudowire Associated Channel Types" registry. +-------+-------------+---------------+ | Value | Description | Reference | +-------+-------------+---------------+ | TBA1 | IP Address | This document | +-------+-------------+---------------+ Table 1: Source MEP ID IP Address TLV Type 6. Security Considerations Thi document does not introduce new security aspects but inherits all security considerations from [RFC5880], [RFC5884], [RFC7726], [I-D.ietf-bfd-multipoint], [RFC8029], and [RFC6425]. 7. Acknowledgements Mirsky Expires October 23, 2017 [Page 4] Internet-Draft Multi-Point BFD over P2MP MPLS LSP April 2017 8. Normative References [I-D.ietf-bess-mvpn-fast-failover] Morin, T. and R. Kebler, "Multicast VPN fast upstream failover", draft-ietf-bess-mvpn-fast-failover-02 (work in progress), March 2017. [I-D.ietf-bfd-multipoint] Katz, D., Ward, D., and J. Networks, "BFD for Multipoint Networks", draft-ietf-bfd-multipoint-09 (work in progress), October 2016. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed., "MPLS Generic Associated Channel", RFC 5586, DOI 10.17487/RFC5586, June 2009, . [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, . [RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, "Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs)", RFC 5884, DOI 10.17487/RFC5884, June 2010, . [RFC6425] Saxena, S., Ed., Swallow, G., Ali, Z., Farrel, A., Yasukawa, S., and T. Nadeau, "Detecting Data-Plane Failures in Point-to-Multipoint MPLS - Extensions to LSP Ping", RFC 6425, DOI 10.17487/RFC6425, November 2011, . [RFC6428] Allan, D., Ed., Swallow, G., Ed., and J. Drake, Ed., "Proactive Connectivity Verification, Continuity Check, and Remote Defect Indication for the MPLS Transport Profile", RFC 6428, DOI 10.17487/RFC6428, November 2011, . [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and L. Yong, "The Use of Entropy Labels in MPLS Forwarding", RFC 6790, DOI 10.17487/RFC6790, November 2012, . Mirsky Expires October 23, 2017 [Page 5] Internet-Draft Multi-Point BFD over P2MP MPLS LSP April 2017 [RFC7726] Govindan, V., Rajaraman, K., Mirsky, G., Akiya, N., and S. Aldrin, "Clarifying Procedures for Establishing BFD Sessions for MPLS Label Switched Paths (LSPs)", RFC 7726, DOI 10.17487/RFC7726, January 2016, . [RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N., Aldrin, S., and M. Chen, "Detecting Multiprotocol Label Switched (MPLS) Data-Plane Failures", RFC 8029, DOI 10.17487/RFC8029, March 2017, . Author's Address Greg Mirsky ZTE Corp. Email: gregimirsky@gmail.com Mirsky Expires October 23, 2017 [Page 6]