Network Working Group H. Chen Internet-Draft M. McBride Intended status: Standards Track Futurewei Expires: 10 September 2023 A. Wang China Telecom G. Mishra Verizon Inc. Y. Fan Casa Systems L. Liu Fujitsu X. Liu IBM Corporation 9 March 2023 OSPF Extensions for BIER-TE draft-ietf-bier-te-ospf-04 Abstract This document describes OSPF extensions for distributing BitPositions configured on the links in "Bit Index Explicit Replication Traffic Engineering" (BIER-TE) domain. 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 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 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 10 September 2023. Chen, et al. Expires 10 September 2023 [Page 1] Internet-Draft OSPF for BIER-TE March 2023 Copyright Notice Copyright (c) 2023 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2 2. Extensions to OSPFv2 . . . . . . . . . . . . . . . . . . . . 3 3. Security Considerations . . . . . . . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 6.1. Normative References . . . . . . . . . . . . . . . . . . 5 6.2. Informative References . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction [RFC9262] introduces Bit Index Explicit Replication (BIER) Traffic/ Tree Engineering (BIER-TE). It is an architecture for per-packet stateless explicit point to multipoint (P2MP) multicast path/tree. A link in a BIER-TE domain has its BitPositions. For a link between two nodes X and Y, there are two BitPositions for two forward connected adjacencies. These two adjacency BitPositions could be configured on nodes X and Y respectively. The BitPosition configured on X is the forward connected adjacency of Y. The BitPosition configured on Y is the forward connected adjacency of X. This document proposes OSPF extensions for distributing BitPositions configured on the links in "Bit Index Explicit Replication Traffic Engineering" (BIER-TE) domain. 1.1. Terminology BIER: Bit Index Explicit Replication. BIER-TE: BIER Traffic Engineering. Chen, et al. Expires 10 September 2023 [Page 2] Internet-Draft OSPF for BIER-TE March 2023 BFR: Bit-Forwarding Router. BFIR: Bit-Forwarding Ingress Router. BFER: Bit-Forwarding Egress Router. BFR-id: BFR Identifier. It is a number in the range [1,65535]. BFR-NBR: BFR Neighbor. LSA: Link State Advertisement. OSPF: Open Shortest Path First. 2. Extensions to OSPFv2 This section describes protocol extensions to OSPFv2 for distributing BIER-TE information such as the BitPositions configured on the links in a BIER-TE domain. [RFC7684] defines the OSPFv2 Extended Link TLV to advertise the information about a link. Multiple Link TLVs for the links of a router are included in the OSPFv2 Extended Link Opaque LSA of the router. The OSPFv2 Extended Link TLV has the following format: 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 (1) | Length (Variable) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Type | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Data | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-TLVs (variable) | ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: OSPFv2 Extended Link TLV Type: 1. Length: Variable, dependent on Sub-TLVs. Link Type, Link ID and Link Data: They are defined in Section A.4.2 Chen, et al. Expires 10 September 2023 [Page 3] Internet-Draft OSPF for BIER-TE March 2023 of [RFC2328]. Reserved: MUST be set to 0 on transmission and MUST be ignored on reception. Under the OSPFv2 Extended Link TLV for a link, a Sub-TLV, called BIER-TE Sub-TLV, is defined for distributing BIER-TE information about the link. A BIER-TE Sub-TLV is included in the Link TLV for a link of Link Type Point-to-Point or Broadcast (or say LAN or Transit Network). The BIER-TE Sub-TLV has the following format: 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 (TBD1) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-domain-id | MT-ID | BAR | IPA | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BitPosition | DrEndBitPosition | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: BIER-TE Sub-TLV Type: TBD1 is to be assigned by IANA. Length: Variable. sub-domain-id: Unique value identifying a BIER-TE sub-domain. MT-ID: Multi-Topology ID identifying the topology that is associated with the BIER-TE sub-domain. BAR: Single-octet BIER Algorithm used to calculate underlay paths to reach other BFRs. Values are allocated from the "BIER Algorithm" registry defined in [RFC8401]. IPA: Single-octet IGP Algorithm used to either modify, enhance, or replace the calculation of underlay paths to reach other BFRs as defined by the BAR value. Values are defined in the "IGP Algorithm Types" registry. BitPosition: A 2-octet field encoding the BitPosition locally configured on the link/interface when the Link Type of the link in the OSPFv2 Extended Link TLV containing this Sub-TLV is 1 (i.e., Point-to-Point connection to another router) or 2 (i.e., connection to Transit Network or say LAN). Chen, et al. Expires 10 September 2023 [Page 4] Internet-Draft OSPF for BIER-TE March 2023 DrEndBitPosition: A 2-octet field encoding the BitPosition of the connection on the designated router (DR) end. This field is valid when the Link Type in the OSPFv2 Extended Link TLV containing this Sub-TLV is 2 (i.e., Transit Network or LAN). For the other value of the Link Type, this field MUST be ignored. The DrEndBitPosition may be configured on the link/ interface to a transit network (i.e., broadcast link or say LAN) as described in [I-D.chen-bier-te-lan]. 3. Security Considerations Protocol extensions defined in this document do not affect the OSPF security other than those as discussed in the Security Considerations section of [RFC7684]. 4. IANA Considerations Under "OSPFv2 Extended Link TLV Sub-TLVs registry" as defined in [RFC7684], IANA is requested to assign a new registry value for BIER- TE Sub-TLV as follows: +==============+===================+=====================+ | Value | Description | reference | +==============+===================+=====================+ | TBD1 (25) | BIER-TE | This document | +--------------+-------------------+---------------------+ 5. Acknowledgements The authors would like to thank Acee Lindem, Les Ginsberg, Tony Przygienda and Toerless Eckert for their comments on this work. 6. References 6.1. 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, . [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, DOI 10.17487/RFC2328, April 1998, . Chen, et al. Expires 10 September 2023 [Page 5] Internet-Draft OSPF for BIER-TE March 2023 [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute Advertisement", RFC 7684, DOI 10.17487/RFC7684, November 2015, . [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, . [RFC9262] Eckert, T., Ed., Menth, M., and G. Cauchie, "Tree Engineering for Bit Index Explicit Replication (BIER-TE)", RFC 9262, DOI 10.17487/RFC9262, October 2022, . 6.2. Informative References [I-D.chen-bier-te-lan] Chen, H., McBride, M., Wang, A., Mishra, G. S., Liu, L., and X. Liu, "BIER-TE for Broadcast Link", Work in Progress, Internet-Draft, draft-chen-bier-te-lan-04, 22 December 2022, . [RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation for Bit Index Explicit Replication (BIER) in MPLS and Non- MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January 2018, . [RFC8401] Ginsberg, L., Ed., Przygienda, T., Aldrin, S., and Z. Zhang, "Bit Index Explicit Replication (BIER) Support via IS-IS", RFC 8401, DOI 10.17487/RFC8401, June 2018, . Authors' Addresses Huaimo Chen Futurewei Boston, MA, United States of America Email: Huaimo.chen@futurewei.com Chen, et al. Expires 10 September 2023 [Page 6] Internet-Draft OSPF for BIER-TE March 2023 Mike McBride Futurewei Email: michael.mcbride@futurewei.com Aijun Wang China Telecom Beiqijia Town, Changping District Beijing 102209 China Email: wangaj3@chinatelecom.cn Gyan S. Mishra Verizon Inc. 13101 Columbia Pike Silver Spring, MD 20904 United States of America Phone: 301 502-1347 Email: gyan.s.mishra@verizon.com Yanhe Fan Casa Systems United States of America Email: yfan@casa-systems.com Lei Liu Fujitsu United States of America Email: liulei.kddi@gmail.com Xufeng Liu IBM Corporation United States of America Email: xufeng.liu.ietf@gmail.com Chen, et al. Expires 10 September 2023 [Page 7]