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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Unused Reference: 'ISO9577' is defined on line 347, but no explicit reference was found in the text == Outdated reference: A later version (-13) exists of draft-ietf-bier-ping-05 Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 BIER WG Quan Xiong 3 Internet-Draft Greg Mirsky 4 Intended status: Standards Track ZTE Corporation 5 Expires: January 4, 2020 Fangwei Hu 6 Individual 7 Chang Liu 8 China Unicom 9 July 3, 2019 11 BIER BFD 12 draft-hu-bier-bfd-04.txt 14 Abstract 16 Point to multipoint (P2MP) BFD is designed to verify multipoint 17 connectivity. This document specifies the application of P2MP BFD in 18 BIER network. 20 Status of This Memo 22 This Internet-Draft is submitted in full conformance with the 23 provisions of BCP 78 and BCP 79. 25 Internet-Drafts are working documents of the Internet Engineering 26 Task Force (IETF). Note that other groups may also distribute 27 working documents as Internet-Drafts. The list of current Internet- 28 Drafts is at https://datatracker.ietf.org/drafts/current/. 30 Internet-Drafts are draft documents valid for a maximum of six months 31 and may be updated, replaced, or obsoleted by other documents at any 32 time. It is inappropriate to use Internet-Drafts as reference 33 material or to cite them other than as "work in progress." 35 This Internet-Draft will expire on January 4, 2020. 37 Copyright Notice 39 Copyright (c) 2019 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (https://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 55 2. Conventions used in this document . . . . . . . . . . . . . . 3 56 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 57 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 58 3. BIER BFD Encapsulation . . . . . . . . . . . . . . . . . . . 3 59 4. BIER BFD Session Bootstrapping . . . . . . . . . . . . . . . 3 60 4.1. BIER OAM Bootstrapping . . . . . . . . . . . . . . . . . 3 61 4.2. IGP protocol Bootstrapping . . . . . . . . . . . . . . . 4 62 4.2.1. IS-IS extension for BIER BFD . . . . . . . . . . . . 4 63 4.2.2. OSPF extension for BIER BFD . . . . . . . . . . . . . 5 64 5. Discriminators and Packet Demultiplexing . . . . . . . . . . 6 65 6. Active Tail in BIER BFD . . . . . . . . . . . . . . . . . . . 6 66 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 67 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 68 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 69 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 70 10.1. Normative References . . . . . . . . . . . . . . . . . . 7 71 10.2. Informative References . . . . . . . . . . . . . . . . . 8 72 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 74 1. Introduction 76 Bit Index Explicit Replication (BIER) [RFC8279] provides forwarding 77 of multicast data packets through a multicast domain. It does so 78 without requiring any explicit tree-building protocol and without 79 requiring intermediate nodes to maintain any per-flow state. 81 [RFC8562] defines a method of using Bidirectional Forwarding 82 Detection (BFD) to monitor and detect unicast failures between the 83 sender (head) and one or more receivers (tails) in multipoint or 84 multicast networks. [RFC8563] describes active tail extensions to 85 the BFD protocol for multipoint networks. 87 This document describes the procedures for using such mode of BFD 88 protocol to monitor connectivity between a multipoint sender, Bit- 89 Forwarding Ingress Router (BFIR), and a set of one or more multipoint 90 receivers,Bit-Forwarding Egress Routers (BFERs). The BIER BFD only 91 supports the unidirectional multicast. This document defines the use 92 of P2MP BFD as per [RFC8562], and active tail as per [RFC8563] for 93 BIER-specific domain. 95 2. Conventions used in this document 97 2.1. Terminology 99 This document uses the acronyms defined in [RFC8279] along with the 100 following: 102 BFD: Bidirectional Forwarding Detection. 104 OAM: Operations, Administration, and Maintenance. 106 P2MP: Point to Multi-Point. 108 2.2. Requirements Language 110 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 111 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 112 "OPTIONAL" in this document are to be interpreted as described in BCP 113 14 [RFC2119] [RFC8174] when, and only when, they appear in all 114 capitals, as shown here. 116 3. BIER BFD Encapsulation 118 BIER BFD encapsulation uses the BIER OAM packet format defined in 119 [I-D.ietf-bier-ping]. The value of the Msg Type field MUST be set to 120 BIER BFD (TBD1 by IANA ). BFD Control Packet, defined in Section 4 121 [RFC5880] immediately follows the BIER OAM header. The operation of 122 Multipoint BFD with the BFD Control Packet is described in [RFC8562]. 124 4. BIER BFD Session Bootstrapping 126 As defined in [RFC8562], BIER BFD session MAY be established to 127 monitor the state of the multipoint path. The BIER BFD session could 128 be created for each multipoint path and the set of BFERs over which 129 the BFIR wishes to run BIER BFD. The BFIR MUST advertise the BFD 130 Discriminator along with the corresponding multipoint path to the set 131 of BFERs. Bootstrapping a BIER BFD session MAY use BIER OAM message 132 section 4.1 or the control plane section 4.2. 134 The BIER BFD bootstrapping MUST be repeated when the value of this 135 discriminator being changed. 137 4.1. BIER OAM Bootstrapping 139 The BIER OAM could be used for bootstrapping the BIER BFD session. 140 The BFIR sends the BIER OAM Echo request message carrying a BFD 141 discriminator TLV which immediately follows the Target SI-Bitstring 142 TLV (section 3.3.2 [I-D.ietf-bier-ping]). 144 The Target SI-Bitstring TLV MUST be used to carry the set of BFER 145 information (including Sub-domain-id, Set ID, BS Len, Bitstring) for 146 the purpose of session establishment. 148 The BFD discriminator TLV is a new TLV for BIER OAM TLV with the type 149 (TBD2 by IANA) and the length of 4. The value contains the 4-byte 150 local discriminator generated by BFIR for this session. This 151 discriminator MUST subsequently be used as the My Discriminator field 152 in the BIER BFD session packets sent by BFIR. The format is as 153 follows. 155 0 1 2 3 156 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 1 157 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 158 | Type=TBD2 | Length | 159 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 160 | My Discriminator | 161 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 163 Figure 1: BFD discriminator TLV 165 4.2. IGP protocol Bootstrapping 167 An alternative option to bootstrap the BIER BFD is to advertise the 168 BFD information in control plane. This document defines a new BIER 169 BFD Sub-sub-TLV carried in IS-IS and OSPF protocol. 171 The BFIR generates the My Discriminator value for each multicast flow 172 and advertises it to the expecting BFERs which is indicated by the 173 Bitstring which is carried in BIER BFD sub-sub-TLV. The 174 corresponding BFERs SHOULD store the My Discriminator value for 175 packet Demultiplexing. 177 4.2.1. IS-IS extension for BIER BFD 179 The new BIER BFD Sub-sub-TLV is carried within the BIER Info sub-TLV 180 defined in [RFC8401]. The format is as follows. 182 0 1 2 3 183 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 1 184 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 | Type | Length | 186 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 | My Discriminator | 188 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 | RESERVED | BIFT-id | 190 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 191 | BitString (first 32 bits) ~ 192 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 ~ ~ 194 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 195 ~ BitString (last 32 bits) | 196 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 198 Figure 2: BIER BFD Sub-sub-TLV for IS-IS extension 200 Type: TBD3 by IANA. 202 Length: Length of the BIER BFD Sub-sub-TLV for IS-IS extension, in 203 bytes. 205 My Discriminator: A unique, nonzero discriminator value generated by 206 BFIR for each multipoint path. 208 The BitString field carries the set of BFR-IDs of BFER(s) that the 209 BFIR expects to establish BIER BFD session. 211 The BIFT-id represents a particular Bit Index Forwarding Table (BIFT) 212 as per [RFC8279]. 214 4.2.2. OSPF extension for BIER BFD 216 The new BIER BFD Sub-TLV is a sub-TLV of the BIER Sub-TLV defined in 217 [RFC8444]. The format is as follows. 219 0 1 2 3 220 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 1 221 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 222 | Type | Length | 223 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 224 | My Discriminator | 225 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 226 | RESERVED | BIFT-id | 227 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 228 | BitString (first 32 bits) ~ 229 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 230 ~ ~ 231 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 232 ~ BitString (last 32 bits) | 233 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 235 Figure 3: BIER BFD Sub-TLV for OSPF extension 237 Type: TBD4 by IANA. 239 Length: Length of the BIER BFD Sub-TLV for OSPF extension, in bytes. 241 Other fields in BIER BFD Sub-TLV is the same with section 4.2.1. 243 5. Discriminators and Packet Demultiplexing 245 As defined in [RFC8562], the BFIR sends BFD Control packets over the 246 multipoint path via the BIER BFD session with My Discriminator set to 247 the value assigned by the BFIR and the value of the Your 248 Discriminator set to zero. The set of BFERs MUST demultiplex BFD 249 packets based on a combination of the source address, My 250 Discriminator value. The source address is BFIR-id and BIER MPLS 251 Label (MPLS network) or BFIR-id and BIFT-id (Non-MPLS network) for 252 BIER BFD. The My Discriminator value is advertised in BIER BFD 253 bootstrapping using one of options described in section 4. 255 6. Active Tail in BIER BFD 257 [RFC8563] defined an extension for Multipoint BFD, which allows the 258 head to discover the state of a multicast distribution tree for any 259 sub-set of tails. For BIER BFD in active tail mode, the BFIR may 260 learn the state and connectivity of the BFERs. As per [RFC8563], the 261 BFIR uses a combination of multicast Poll sequence messages and 262 unicast Poll messages. The unicast messages must be sent over the 263 path which is disjoint from the multicast distribution tree. 265 7. Security Considerations 267 For BIER OAM packet procssing security considerations, see 268 [I-D.ietf-bier-ping]. 270 For general multipoint BFD security considerations, see [RFC8562]. 272 No additional security issues are raised in this document beyond 273 those that exist in the referenced BFD documents. 275 8. Acknowledgements 277 Authors would like to thank the comments and suggestions from Sandy 278 Zhang, Jeffrey (Zhaohui) Zhang, Donald Eastlake 3rd. 280 9. IANA Considerations 282 IANA is requested to assign new type from the BIER OAM Message Type 283 registry as follows: 285 +--------+---------------------------------+------------------+ 286 | Value | Description | Reference | 287 +--------+---------------------------------+------------------+ 288 | TBD1 | BIER BFD | [this document] | 289 | TBD2 | BFD discriminator TLV | [this document] | 290 | TBD3 | BIER BFD Sub-sub-TLV for IS-IS | [this document] | 291 | TBD4 | BIER BFD Sub-TLV for OSPF | [this document] | 292 +--------+---------------------------------+------------------+ 294 Table 1 296 10. References 298 10.1. Normative References 300 [I-D.ietf-bier-ping] 301 Kumar, N., Pignataro, C., Akiya, N., Zheng, L., Chen, M., 302 and G. Mirsky, "BIER Ping and Trace", draft-ietf-bier- 303 ping-05 (work in progress), April 2019. 305 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 306 Requirement Levels", BCP 14, RFC 2119, 307 DOI 10.17487/RFC2119, March 1997, 308 . 310 [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 311 (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, 312 . 314 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 315 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 316 May 2017, . 318 [RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., 319 Przygienda, T., and S. Aldrin, "Multicast Using Bit Index 320 Explicit Replication (BIER)", RFC 8279, 321 DOI 10.17487/RFC8279, November 2017, 322 . 324 [RFC8401] Ginsberg, L., Ed., Przygienda, T., Aldrin, S., and Z. 325 Zhang, "Bit Index Explicit Replication (BIER) Support via 326 IS-IS", RFC 8401, DOI 10.17487/RFC8401, June 2018, 327 . 329 [RFC8444] Psenak, P., Ed., Kumar, N., Wijnands, IJ., Dolganow, A., 330 Przygienda, T., Zhang, J., and S. Aldrin, "OSPFv2 331 Extensions for Bit Index Explicit Replication (BIER)", 332 RFC 8444, DOI 10.17487/RFC8444, November 2018, 333 . 335 [RFC8562] Katz, D., Ward, D., Pallagatti, S., Ed., and G. Mirsky, 336 Ed., "Bidirectional Forwarding Detection (BFD) for 337 Multipoint Networks", RFC 8562, DOI 10.17487/RFC8562, 338 April 2019, . 340 [RFC8563] Katz, D., Ward, D., Pallagatti, S., Ed., and G. Mirsky, 341 Ed., "Bidirectional Forwarding Detection (BFD) Multipoint 342 Active Tails", RFC 8563, DOI 10.17487/RFC8563, April 2019, 343 . 345 10.2. Informative References 347 [ISO9577] ISO/IEC TR 9577:1999,, "International Organization for 348 Standardization "Information technology - 349 Telecommunications and Information exchange between 350 systems - Protocol identification in the network layer"", 351 1999. 353 Authors' Addresses 354 Quan Xiong 355 ZTE Corporation 356 No.6 Huashi Park Rd 357 Wuhan, Hubei 430223 358 China 360 Phone: +86 27 83531060 361 Email: xiong.quan@zte.com.cn 363 Greg Mirsky 364 ZTE Corporation 365 USA 367 Email: gregimirsky@gmail.com 369 Fangwei Hu 370 Individual 372 Email: hufwei@gmail.com 374 Chang Liu 375 China Unicom 376 No.9 Shouti Nanlu 377 Beijing 100048 378 China 380 Phone: +86-010-68799999-7294 381 Email: liuc131@chinaunicom.cn