Network Working Group H. Chen Internet-Draft M. McBride Intended status: Standards Track Futurewei Expires: 4 August 2024 Z. Zhang ZTE Corporation A. Wang China Telecom G. Mishra Verizon Inc. Y. Fan Casa Systems 1 February 2024 OSPF Extensions for BIER-TE draft-ietf-bier-te-ospf-10 Abstract This document describes OSPFv2 and OSPFv3 extensions for distributing the BitPositions configured on a Bit-Forwarding Router (BFR) with MPLS and non-MPLS encapsulation for "Bit Index Explicit Replication Traffic Engineering" (BIER-TE) in a 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 4 August 2024. Chen, et al. Expires 4 August 2024 [Page 1] Internet-Draft OSPF for BIER-TE February 2024 Copyright Notice Copyright (c) 2024 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 2. Extensions to OSPFv2 . . . . . . . . . . . . . . . . . . . . 3 2.1. Link BitPosition . . . . . . . . . . . . . . . . . . . . 3 2.2. Routed and Localdecap BitPositions . . . . . . . . . . . 5 2.3. BIER-TE Encapsulation Sub-TLVs . . . . . . . . . . . . . 6 2.3.1. BIER-TE MPLS Encapsulation Sub-TLV . . . . . . . . . 7 2.3.2. BIER-TE Non-MPLS Encapsulation Sub-TLV . . . . . . . 7 3. Extensions to OSPFv3 . . . . . . . . . . . . . . . . . . . . 8 3.1. Link BitPosition . . . . . . . . . . . . . . . . . . . . 8 3.2. Routed and Localdecap BitPositions . . . . . . . . . . . 9 3.3. BIER-TE Encapsulation Sub-TLVs . . . . . . . . . . . . . 9 4. Security Considerations . . . . . . . . . . . . . . . . . . . 9 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 5.1. OSPFv2 . . . . . . . . . . . . . . . . . . . . . . . . . 10 5.2. OSPFv3 . . . . . . . . . . . . . . . . . . . . . . . . . 11 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.1. Normative References . . . . . . . . . . . . . . . . . . 11 6.2. Informative References . . . . . . . . . . . . . . . . . 12 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 13 Contributors' Addresses . . . . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 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. There are three types of BitPositions (BPs) in a BIER-TE domain: link BitPosition (BP), routed BP and localdecap BP. A link BP is a BP configured on a link from Bit-Forwarding Router (BFR) X to BFR Y for a forward connected adjacency from X to Y. A routed BP is a BP configured on BFR X for a forward routed adjacency from X to a remote Chen, et al. Expires 4 August 2024 [Page 2] Internet-Draft OSPF for BIER-TE February 2024 BFR Z not directly connected to X. A localdecap BP is a BP configured on a BFR. [RFC8444] describes OSPFv2 Extensions for distributing the BFR identifier (BFR-id) configured on a BFR. [I-D.ietf-bier-ospfv3-extensions] describes OSPFv3 Extensions for distributing the BFR identifier (BFR-id) configured on a BFR. The advertisement of MPLS and Non-MPLS encapsulation for BIER is speficied in [RFC8444], [I-D.ietf-bier-ospfv3-extensions], and [I-D.ietf-bier-lsr-non-mpls-extensions]. This document specifies OSPFv2 and OSPFv3 extensions for distributing the BitPositions configured on a BFR with MPLS and Non-MPLS encapsulation for BIER-TE in a BIER-TE domain. The BitPositions distributed may be used by a BFR as a Point of Local Repair (PLR) for Fast-ReRoute (FRR). 2. Extensions to OSPFv2 This section describes protocol extensions to OSPFv2 for distributing the BitPositions configured on a BFR in a BIER-TE domain. 2.1. Link BitPosition This section defines a Sub-TLV for distributing a link BitPosition (BP). [RFC7684] defines the OSPFv2 Extended Link TLV to advertise the information about a link. Only one OSPFv2 Extended Link TLV SHALL be advertised in each OSPFv2 Extended Link Opaque LSA. 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. Chen, et al. Expires 4 August 2024 [Page 3] Internet-Draft OSPF for BIER-TE February 2024 Length: Variable, dependent on Sub-TLVs. Link Type, Link ID and Link Data: They are defined in Section A.4.2 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 Link-BP Sub-TLV, is defined for distributing a link BitPosition. A Link-BP Sub-TLV is included in the Link TLV for a link of Link Type P2P (Point-to-Point) or Broadcast (or say LAN or Transit Network). The Link-BP 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-TLVs ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: Link-BP Sub-TLV Type: TBD1 is to be assigned by IANA. Length: Variable. sub-domain-id, MT-ID, BAR and IPA: They are defined in Section 2.1 of [RFC8444]. 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). DrEndBitPosition: A 2-octet field encoding the BitPosition of the Chen, et al. Expires 4 August 2024 [Page 4] Internet-Draft OSPF for BIER-TE February 2024 connection on the designated router (DR) end. This field exists 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 NOT exist. 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]. 2.2. Routed and Localdecap BitPositions A TLV, called Node BPs TLV, is defined within the body of the OSPF Router Information (RI) Opaque Link State Advertisement (LSA) [RFC7770]. The TLV contains Sub-TLVs. Two types of Sub-TLVs are defined. One is for a Routed BitPosition and the other for a Localdecap BitPosition. The Node BPs 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 (TBD2) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-domain-id | MT-ID | BAR | IPA | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-TLVs ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Node BPs TLV Type: TBD2 is to be assigned by IANA. Length: Variable. sub-domain-id, MT-ID, BAR and IPA: They are defined in Section 2.1 of [RFC8444]. Sub-TLVs: They are Routed-BP Sub-TLVs for Routed BPs and/or Localdecap-BP Sub-TLV for Localdecap BP. The Routed-BP Sub-TLV has the following format: Chen, et al. Expires 4 August 2024 [Page 5] Internet-Draft OSPF for BIER-TE February 2024 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 (TBD3) | Length(4) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BitPosition | BFR-id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: Routed-BP Sub-TLV Type: TBD3 is to be assigned by IANA.. Length: It is 4. BitPosition: A 2-octet field encoding the BitPosition configured on a BFR for a forward routed adjacency to a remote BFR. BFR-id: A 2-octet field encoding the BFR-id of the remote BFR. The Localdecap-BP 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 (TBD4) | Length(2) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BitPosition | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: Localdecap-BP Sub-TLV Type: TBD4 is to be assigned by IANA. Length: It is 2. BitPosition: A 2-octet field encoding the localdecap BitPosition configured on a BFR. 2.3. BIER-TE Encapsulation Sub-TLVs Two BIER-TE Encapsulation Sub-TLVs are defined. One is BIER-TE MPLS Encapsulation Sub-TLV and the other is BIER-TE non-MPLS Encapsulation Sub-TLV. They are similar to the BIER MPLS Encapsulation Sub-TLV defined in Section 2.2 of [RFC8444]. They are advertised with the Node BPs TLV. Their flooding scope is the same as the one in Section 2.3 of [RFC8444]. Chen, et al. Expires 4 August 2024 [Page 6] Internet-Draft OSPF for BIER-TE February 2024 2.3.1. BIER-TE MPLS Encapsulation Sub-TLV The format of BIER-TE MPLS Encapsulation Sub-TLV is illustrated in Figure 6. 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 (TBD5) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max SI | Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BS Len| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: BIER-TE MPLS Encapsulation Sub-TLV Type: TBD5 is to be assigned by IANA. Length: 8. Max SI: A 1 octet field encoding the maximum Set Identifier (Section 1 of [RFC8279]), used in the encapsulation for this BIER-TE sub-domain for this bitstring length. Label: A 3 octet field, where the 20 rightmost bits represent the first label in the label range. The 4 leftmost bits MUST be ignored. BS Len: A 4 bits field encoding the supported BitString length associated with the BPs configured on the BFR and in the BP Sub-TLVs and TLV with the BIER-TE Encapsulation Sub-TLV. The values allowed in this field are specified in Section 2 of [RFC8296]. Reserved: SHOULD be set to 0 on transmission and MUST be ignored on reception. 2.3.2. BIER-TE Non-MPLS Encapsulation Sub-TLV The format of BIER-TE Non-MPLS Encapsulation Sub-TLV is illustrated in Figure 7. Chen, et al. Expires 4 August 2024 [Page 7] Internet-Draft OSPF for BIER-TE February 2024 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 (TBD6) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max SI | BIFT-ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BS Len| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: BIER-TE Non-MPLS Encapsulation Sub-TLV Type: TBD6 is to be assigned by IANA. Length: 8. BIFT-ID: A 3 octet field, where the 20 rightmost bits represent the first value in the value range. The 4 leftmost bits MUST be ignored. The other fields are the same as those for BIER-TE MPLS Encapsulation Sub-TLV. 3. Extensions to OSPFv3 This section describes protocol extensions to OSPFv3 for distributing the BitPositions configured on a BFR in a BIER-TE domain. 3.1. Link BitPosition [RFC8362] defines OSPFv3 Extended Router LSA, which may include multiple Router-Link TLVs. A Router-Link TLV defines a single router link. A Router-Link TLV may include a Link-BP Sub-TLV below for distributing a link BP. 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 (TBD7) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-domain-id | MT-ID | BAR | IPA | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BitPosition | DrEndBitPosition | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-TLVs ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8: Link-BP Sub-TLV in Router-Link TLV Chen, et al. Expires 4 August 2024 [Page 8] Internet-Draft OSPF for BIER-TE February 2024 Type: TBD7 is to be assigned by IANA. Length: Variable. sub-domain-id, MT-ID, BAR and IPA: They are defined in Section 2.1 of [I-D.ietf-bier-ospfv3-extensions]. BitPosition: A 2-octet field encoding the BitPosition locally configured on the link/interface when the Link Type of the link in the Router-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). DrEndBitPosition: A 2-octet field encoding the BitPosition of the connection on the designated router (DR) end. This field exists when the Link Type in the Router-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 NOT exist. 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]. 3.2. Routed and Localdecap BitPositions The Node BPs TLV, Routed BP Sub-TLV and Localdecap BP Sub-TLV defined in Section 2.2 are reused in OSPVv3 for distributing the routed BitPositions and the localdecap BitPosition configured on a BFR. 3.3. BIER-TE Encapsulation Sub-TLVs Two BIER-TE Encapsulation Sub-TLVs defined in Section 2.3 are reused in OSPFv3. They are similar to the BIER MPLS Encapsulation Sub-TLV defined in Section 2.2 of [I-D.ietf-bier-ospfv3-extensions]. They are advertised with the Node BPs TLV. Their flooding scope is the same as the one in Section 2.3 of [I-D.ietf-bier-ospfv3-extensions]. 4. 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] and [RFC8362]. 5. IANA Considerations Chen, et al. Expires 4 August 2024 [Page 9] Internet-Draft OSPF for BIER-TE February 2024 5.1. OSPFv2 Under "OSPFv2 Extended Link TLV Sub-TLVs" registry as defined in [RFC7684], IANA is requested to assign a new registry value for Link- BP Sub-TLV, BIER-TE MPLS Encapsulation Sub-TLV and BIER-TE Non-MPLS Encapsulation Sub-TLV as follows: +===========+================================+===============+ | Value | Description | reference | +===========+================================+===============+ | TBD1 (30) | Link-BP | This document | +-----------+--------------------------------+---------------+ | TBD5 (31) | BIER-TE MPLS Encapsulation | This document | +-----------+--------------------------------+---------------+ | TBD6 (32) | BIER-TE Non-MPLS Encapsulation | This document | +-----------+--------------------------------+---------------+ Under "OSPF Router Information (RI) TLVs" registry as defined in [RFC7770], IANA is requested to assign a new registry value for Node BPs TLV as follows: +==============+===================+=====================+ | Value | Description | reference | +==============+===================+=====================+ | TBD2 (21) | Node BPs | This document | +--------------+-------------------+---------------------+ IANA is requested to create a new subregistry called the "OSPF Node BPs Sub-TLVs" under the "Open Shortest Path First (OSPF) Parameters" registry. The initial values are as follows: +=============+================================+===============+ | Value | Description | reference | +=============+================================+===============+ | 0 | Reserved | This document | +-------------+--------------------------------+---------------+ | TBD3(1) | Routed BP | This document | +-------------+--------------------------------+---------------+ | TBD4(2) | Localdecap BP | This document | +-------------+--------------------------------+---------------+ | 31 | BIER-TE MPLS Encapsulation | This document | +-------------+--------------------------------+---------------+ | 32 | BIER-TE Non-MPLS Encapsulation | This document | +-------------+--------------------------------+---------------+ |3-30,33-65535| To be allocated in First Come First Served | +-------------+--------------------------------+---------------+ Chen, et al. Expires 4 August 2024 [Page 10] Internet-Draft OSPF for BIER-TE February 2024 5.2. OSPFv3 Under "OSPFv3 Extended-LSA Sub-TLVs" registry as defined in [RFC8362], IANA is requested to assign a new registry value for Link- BP Sub-TLV, BIER-TE MPLS Encapsulation Sub-TLV and BIER-TE Non-MPLS Encapsulation Sub-TLV as follows: +===========+================================+===============+ | Value | Description | reference | +===========+================================+===============+ | TBD7 (30) | Link-BP | This document | +-----------+--------------------------------+---------------+ | 31 | BIER-TE MPLS Encapsulation | This document | +-----------+--------------------------------+---------------+ | 32 | BIER-TE Non-MPLS Encapsulation | This document | +-----------+--------------------------------+---------------+ 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, . [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, . [RFC7770] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and S. Shaffer, "Extensions to OSPF for Advertising Optional Router Capabilities", RFC 7770, DOI 10.17487/RFC7770, February 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Chen, et al. Expires 4 August 2024 [Page 11] Internet-Draft OSPF for BIER-TE February 2024 [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, . [RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and F. Baker, "OSPFv3 Link State Advertisement (LSA) Extensibility", RFC 8362, DOI 10.17487/RFC8362, April 2018, . [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-08, 18 October 2023, . [I-D.ietf-bier-lsr-non-mpls-extensions] Dhanaraj, S., Yan, G., Wijnands, I., Psenak, P., Zhang, Z. J., and J. Xie, "LSR Extensions for BIER non-MPLS Encapsulation", Work in Progress, Internet-Draft, draft- ietf-bier-lsr-non-mpls-extensions-02, 27 January 2024, . [I-D.ietf-bier-ospfv3-extensions] Psenak, P., Nainar, N. K., and I. Wijnands, "OSPFv3 Extensions for BIER", Work in Progress, Internet-Draft, draft-ietf-bier-ospfv3-extensions-07, 1 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, . Chen, et al. Expires 4 August 2024 [Page 12] Internet-Draft OSPF for BIER-TE February 2024 [RFC8444] Psenak, P., Ed., Kumar, N., Wijnands, IJ., Dolganow, A., Przygienda, T., Zhang, J., and S. Aldrin, "OSPFv2 Extensions for Bit Index Explicit Replication (BIER)", RFC 8444, DOI 10.17487/RFC8444, November 2018, . Acknowledgments The authors would like to thank Acee Lindem, Les Ginsberg, Tony Przygienda, Jeffrey Zhang and Toerless Eckert for their comments on this work. Contributors' Addresses Yuehua Wei ZTE Corporation China Email: wei.yuehua@zte.com.cn Lei Liu Fujitsu USA Email: liulei.kddi@gmail.com Benchong Xu ZTE Corporation China Email: xu.benchong@zte.com.cn Xufeng Liu Alef Edge USA Email: xufeng.liu.ietf@gmail.com IJsbrand Wijnands Arrcus Email: ice@braindump.be Authors' Addresses Huaimo Chen Futurewei Boston, MA, United States of America Email: hchen.ietf@gmail.com Chen, et al. Expires 4 August 2024 [Page 13] Internet-Draft OSPF for BIER-TE February 2024 Mike McBride Futurewei Email: michael.mcbride@futurewei.com Zheng Zhang ZTE Corporation China Email: zhang.zheng@zte.com.cn 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 Chen, et al. 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