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'I-D.voyer-6man-extension-header-insertion') == Outdated reference: A later version (-13) exists of draft-ietf-rtgwg-segment-routing-ti-lfa-05 == Outdated reference: A later version (-22) exists of draft-ietf-spring-segment-routing-policy-09 Summary: 3 errors (**), 0 flaws (~~), 4 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 SPRING C. Filsfils, Ed. 3 Internet-Draft P. Camarillo, Ed. 4 Intended status: Standards Track Cisco Systems, Inc. 5 Expires: July 15, 2021 J. Leddy 6 Individual Contributor 7 D. Voyer 8 Bell Canada 9 S. Matsushima 10 SoftBank 11 Z. Li 12 Huawei Technologies 13 January 11, 2021 15 SRv6 NET-PGM extension: Insertion 16 draft-filsfils-spring-srv6-net-pgm-insertion-04 18 Abstract 20 Traffic traversing an SR domain is encapsulated in an outer IPv6 21 header for its journey through the SR domain. 23 To implement transport services strictly within the SR domain, the SR 24 domain may require insertion or deletion of an SRH after the outer 25 IPv6 header of the SR domain. Any segment within the SRH is strictly 26 contained within the SR domain. 28 This document extends SRv6 Network Programming 29 [I-D.ietf-spring-srv6-network-programming] with new SR endpoint and 30 transit behaviors to be performed only within the SR domain in any 31 packet owned by the domain. 33 Requirements Language 35 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 36 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 37 "OPTIONAL" in this document are to be interpreted as described in BCP 38 14 [RFC2119] [RFC8174] when, and only when, they appear in all 39 capitals, as shown here. 41 Status of This Memo 43 This Internet-Draft is submitted in full conformance with the 44 provisions of BCP 78 and BCP 79. 46 Internet-Drafts are working documents of the Internet Engineering 47 Task Force (IETF). Note that other groups may also distribute 48 working documents as Internet-Drafts. The list of current Internet- 49 Drafts is at https://datatracker.ietf.org/drafts/current/. 51 Internet-Drafts are draft documents valid for a maximum of six months 52 and may be updated, replaced, or obsoleted by other documents at any 53 time. It is inappropriate to use Internet-Drafts as reference 54 material or to cite them other than as "work in progress." 56 This Internet-Draft will expire on July 15, 2021. 58 Copyright Notice 60 Copyright (c) 2021 IETF Trust and the persons identified as the 61 document authors. All rights reserved. 63 This document is subject to BCP 78 and the IETF Trust's Legal 64 Provisions Relating to IETF Documents 65 (https://trustee.ietf.org/license-info) in effect on the date of 66 publication of this document. Please review these documents 67 carefully, as they describe your rights and restrictions with respect 68 to this document. Code Components extracted from this document must 69 include Simplified BSD License text as described in Section 4.e of 70 the Trust Legal Provisions and are provided without warranty as 71 described in the Simplified BSD License. 73 Table of Contents 75 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 76 2. SRv6 endpoint behaviors . . . . . . . . . . . . . . . . . . . 3 77 2.1. End.B6.Insert: Endpoint bound to an SRv6 policy . . . . . 3 78 2.2. End.B6.Insert.Red: [...] with reduced SRH . . . . . . . . 4 79 3. SR Policy Headend Behaviors . . . . . . . . . . . . . . . . . 5 80 3.1. H.Insert: SR Headend with insertion of an SRv6 Policy . . 5 81 3.2. H.Insert.Red: H.Insert with reduced insertion . . . . . . 5 82 4. Maximum H.Insert MSD Type . . . . . . . . . . . . . . . . . . 6 83 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 84 5.1. SRv6 Endpoint Behaviors . . . . . . . . . . . . . . . . . 6 85 5.2. MSD Types . . . . . . . . . . . . . . . . . . . . . . . . 6 86 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 87 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7 88 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 89 8.1. Normative References . . . . . . . . . . . . . . . . . . 10 90 8.2. Informative References . . . . . . . . . . . . . . . . . 10 91 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 93 1. Introduction 95 Packets transiting an SR Domain may be steered into an SR Policy for 96 a variety of reasons. For example, a PLR router reroutes traffic on 97 a TI-LFA repair path [I-D.ietf-rtgwg-segment-routing-ti-lfa] or when 98 a Binding-SID is expanded [I-D.ietf-spring-segment-routing-policy]. 100 This document extends the SRv6 Network Programming 101 [I-D.ietf-spring-srv6-network-programming] model with new endpoint 102 and transit behaviors enabling the insertion of an SRH after the 103 outer IPv6 header of the SR domain. The operations described in this 104 document must take into account the considerations described in 105 [I-D.voyer-6man-extension-header-insertion]. 107 2. SRv6 endpoint behaviors 109 SRv6 Network Programming Section 4 defines a base set of SRv6 110 endpoint behaviors. This is extended with the behaviors described in 111 this section. 113 2.1. End.B6.Insert: Endpoint bound to an SRv6 policy 115 The "Endpoint bound to an SRv6 Policy" is a variant of the End 116 behavior. 118 One of its applications is to express scalable traffic-engineering 119 policies across multiple domains. It is the one of the SRv6 120 instantiations of a Binding SID [RFC8402]. 122 An End.B6.Insert SID is never the last segment in a SID list, and any 123 SID instantiation must be associated with an SR Policy 124 B[I-D.ietf-spring-segment-routing-policy]. 126 When N receives a packet whose IPv6 DA is S and S is a local 127 End.B6.Insert SID, does: 129 S01. When an SRH is processed { 130 S02. If (Segments Left == 0) { 131 S03. Send an ICMP Parameter Problem message to the Source Address 132 Code TBD-SRH (SR Upper-layer Header Error), 133 Pointer set to the offset of the upper-layer header, 134 interrupt packet processing and discard the packet 135 S04. } 136 S04. If (IPv6 Hop Limit <= 1) { 137 S05. Send an ICMP Time Exceeded message to the Source Address, 138 Code 0 (Hop limit exceeded in transit), 139 interrupt packet processing and discard the packet 140 S06. } 141 S07. max_LE = (Hdr Ext Len / 2) - 1 142 S08. If ((Last Entry > max_LE) or (Segments Left > (Last Entry+1)){ 143 S09. Send an ICMP Parameter Problem to the Source Address, 144 Code 0 (Erroneous header field encountered), 145 Pointer set to the Segments Left field, 146 interrupt packet processing and discard the packet 147 S11. } 148 S12. Decrement Hop Limit by 1 149 S13. Insert a new SRH in between the IPv6 Header and the received 150 SRH containing the list of segments of B 151 S14. Set the IPv6 DA to the first segment of B 152 S15. Resubmit the packet to the egress IPv6 FIB lookup and 153 transmission to the new destination 154 S16. } 156 When processing the Upper-layer header of a packet matching a FIB 157 entry locally instantiated as an SRv6 End.B6.Insert SID, send an ICMP 158 parameter problem message to the Source Address and discard the 159 packet. Error code "SR Upper-layer Header Error", Pointer set to the 160 offset of the upper-layer header. 162 2.2. End.B6.Insert.Red: [...] with reduced SRH 164 This is an optimization of the End.B6.Insert behavior. 166 End.B6.Insert.Red reduces the size of the new SRH by one SID by 167 avoiding the insertion of the first SID in the pushed SRH. In this 168 way, the first SID is only written in the DA and the packet is 169 forwarded according to it. 171 The new SRH is created as described in Section 4.1.1 of [RFC8754]. 173 3. SR Policy Headend Behaviors 175 SRv6 Network Programming defines in Section 5 a set of SR Policy 176 Headend Behaviors. This is extended with the following behaviors 177 defined in this section. 179 3.1. H.Insert: SR Headend with insertion of an SRv6 Policy 181 Node N receives two packets P1=(A, B2) and P2=(A,B2)(B3, B2, B1; 182 SL=1). B2 is neither a local address nor SID of N. 184 N steers the transit packets P1 and P2 into an SRv6 Policy with one 185 SID list . 187 The "H.Insert" transit insertion behavior is defined as follows: 189 1. insert the SRH (B2, S3, S2, S1; SL=3) ;; Ref1, Ref1bis 190 2. set the IPv6 DA = S1 191 3. forward along the shortest path to S1 193 Ref1: The received IPv6 DA is placed as last SID of the inserted SRH. 195 Ref1bis: The SRH is inserted 196 [I-D.voyer-6man-extension-header-insertion] before any other IPv6 197 Routing Extension Header. 199 After the H.Insert behavior, P1 and P2 respectively look like: 201 -(A, S1) (B2, S3, S2, S1; SL=3) 203 -(A, S1) (B2, S3, S2, S1; SL=3) (B3, B2, B1; SL=1) 205 3.2. H.Insert.Red: H.Insert with reduced insertion 207 The H.Insert.Red behavior is an optimization of the H.Insert 208 behavior. It is defined as follows: 210 1. insert the SRH (B2, S3, S2; SL=3) 211 2. set the IPv6 DA = S1 212 3. forward along the shortest path to S1 214 H.Insert.Red will reduce the size of the SRH by one segment by 215 avoiding the insertion of the first SID in the pushed SRH. In this 216 way, the first segment is only introduced in the DA and the packet is 217 forwarded according to it. 219 After the H.Insert.Red behavior, P1 and P2 respectively look like: 221 - (A, S1) (B2, S3, S2; SL=3) 223 - (A, S1) (B2, S3, S2; SL=3) (B3, B2, B1; SL=1) 225 4. Maximum H.Insert MSD Type 227 This document defines the MSD (Maximum SID Depth) for H.Insert 228 behavior and requests the MSD type assignment from the IGP MSD-Types 229 registry created by [RFC8491]. 231 The Maximum H.Insert MSD Type specifies the maximum number of SIDs 232 that can be inserted as part of the "H.insert" behavior: 234 -Max H.insert Type: 43 (Suggested value - to be assigned by IANA) 236 If the advertised value is zero or no value is advertised then the 237 router is assumed not to support any variation of the "H.insert" 238 behavior. 240 5. IANA Considerations 242 5.1. SRv6 Endpoint Behaviors 244 This document requests IANA to allocate the following codepoints 245 within the "SRv6 Endpoint Behaviors" sub-registry under the top-level 246 "Segment Routing Parameters" registry. 248 +-------+--------+-------------------+-----------+ 249 | Value | Hex | Endpoint behavior | Reference | 250 +-------+--------+-------------------+-----------+ 251 | 13 | 0x000D | End.B6.Insert | [This.ID] | 252 | 26 | 0x001A | End.B6.Insert.Red | [This.ID] | 253 +-------+--------+-------------------+-----------+ 255 Table 1: IETF - SRv6 Endpoint Behaviors 257 5.2. MSD Types 259 This document requests IANA to allocate the following codepoint 260 within the "IGP MSD-Types" sub-registry under the top-level "IGP 261 Parameters" registry. 263 +-------+------+-------------------+-----------+ 264 | Value | Hex | Endpoint behavior | Reference | 265 +-------+------+-------------------+-----------+ 266 | 43 | 0x2B | Max H.Insert | [This.ID] | 267 +-------+------+-------------------+-----------+ 269 Table 2: IETF - MSD Types 271 6. Acknowledgements 273 The authors would like to acknowledge Stefano Previdi, Dave Barach, 274 Mark Townsley, Peter Psenak, Thierry Couture, Kris Michielsen, Paul 275 Wells, Robert Hanzl, Dan Ye, Gaurav Dawra, Faisal Iqbal, Jaganbabu 276 Rajamanickam, David Toscano, Asif Islam, Jianda Liu, Yunpeng Zhang, 277 Jiaoming Li, Narendra A.K, Mike Mc Gourty, Bhupendra Yadav, Sherif 278 Toulan, Satish Damodaran, John Bettink, Kishore Nandyala Veera Venk, 279 Jisu Bhattacharya and Saleem Hafeez. 281 7. Contributors 283 Daniel Bernier 284 Bell Canada 285 Canada 287 Email: daniel.bernier@bell.ca 289 Dirk Steinberg 290 Lapishills Consulting Limited 291 Cyprus 293 Email: dirk@lapishills.com 295 Robert Raszuk 296 Bloomberg LP 297 United States of America 299 Email: robert@raszuk.net 301 Bart Peirens 302 Proximus 303 Belgium 305 Email: bart.peirens@proximus.com 307 Hani Elmalky 308 Ericsson 309 United States of America 310 Email: hani.elmalky@gmail.com 312 Prem Jonnalagadda 313 Barefoot Networks 314 United States of America 316 Email: prem@barefootnetworks.com 318 Milad Sharif 319 Barefoot Networks 320 United States of America 322 Email: msharif@barefootnetworks.com 324 David Lebrun 325 Google 326 Belgium 328 Email: dlebrun@google.com 330 Stefano Salsano 331 Universita di Roma "Tor Vergata" 332 Italy 334 Email: stefano.salsano@uniroma2.it 336 Ahmed AbdelSalam 337 Gran Sasso Science Institute 338 Italy 340 Email: ahmed.abdelsalam@gssi.it 342 Gaurav Naik 343 Drexel University 344 United States of America 346 Email: gn@drexel.edu 348 Arthi Ayyangar 349 Arista 350 United States of America 352 Email: arthi@arista.com 354 Satish Mynam 355 Innovium Inc. 356 United States of America 357 Email: smynam@innovium.com 359 Wim Henderickx 360 Nokia 361 Belgium 363 Email: wim.henderickx@nokia.com 365 Shaowen Ma 366 Juniper 367 Singapore 369 Email: mashao@juniper.net 371 Ahmed Bashandy 372 Individual 373 United States of America 375 Email: abashandy.ietf@gmail.com 377 Francois Clad 378 Cisco Systems, Inc. 379 France 381 Email: fclad@cisco.com 383 Kamran Raza 384 Cisco Systems, Inc. 385 Canada 387 Email: skraza@cisco.com 389 Darren Dukes 390 Cisco Systems, Inc. 391 Canada 393 Email: ddukes@cisco.com 395 Patrice Brissete 396 Cisco Systems, Inc. 397 Canada 399 Email: pbrisset@cisco.com 401 Zafar Ali 402 Cisco Systems, Inc. 403 United States of America 404 Email: zali@cisco.com 406 8. References 408 8.1. Normative References 410 [I-D.ietf-spring-srv6-network-programming] 411 Filsfils, C., Camarillo, P., Leddy, J., Voyer, D., 412 Matsushima, S., and Z. Li, "SRv6 Network Programming", 413 draft-ietf-spring-srv6-network-programming-28 (work in 414 progress), December 2020. 416 [I-D.voyer-6man-extension-header-insertion] 417 Voyer, D., Filsfils, C., Dukes, D., Matsushima, S., Leddy, 418 J., Li, Z., and J. Guichard, "Deployments With Insertion 419 of IPv6 Segment Routing Headers", draft-voyer-6man- 420 extension-header-insertion-10 (work in progress), November 421 2020. 423 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 424 Requirement Levels", BCP 14, RFC 2119, 425 DOI 10.17487/RFC2119, March 1997, 426 . 428 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 429 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 430 May 2017, . 432 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 433 Decraene, B., Litkowski, S., and R. Shakir, "Segment 434 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 435 July 2018, . 437 [RFC8491] Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg, 438 "Signaling Maximum SID Depth (MSD) Using IS-IS", RFC 8491, 439 DOI 10.17487/RFC8491, November 2018, 440 . 442 [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J., 443 Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header 444 (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, 445 . 447 8.2. Informative References 449 [I-D.ietf-rtgwg-segment-routing-ti-lfa] 450 Litkowski, S., Bashandy, A., Filsfils, C., Decraene, B., 451 and D. Voyer, "Topology Independent Fast Reroute using 452 Segment Routing", draft-ietf-rtgwg-segment-routing-ti- 453 lfa-05 (work in progress), November 2020. 455 [I-D.ietf-spring-segment-routing-policy] 456 Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and 457 P. Mattes, "Segment Routing Policy Architecture", draft- 458 ietf-spring-segment-routing-policy-09 (work in progress), 459 November 2020. 461 Authors' Addresses 463 Clarence Filsfils (editor) 464 Cisco Systems, Inc. 465 Belgium 467 Email: cf@cisco.com 469 Pablo Camarillo Garvia (editor) 470 Cisco Systems, Inc. 471 Spain 473 Email: pcamaril@cisco.com 475 John Leddy 476 Individual Contributor 477 United States of America 479 Email: john@leddy.net 481 Daniel Voyer 482 Bell Canada 483 Canada 485 Email: daniel.voyer@bell.ca 486 Satoru Matsushima 487 SoftBank 488 1-9-1,Higashi-Shimbashi,Minato-Ku 489 Tokyo 105-7322 490 Japan 492 Email: satoru.matsushima@g.softbank.co.jp 494 Zhenbin Li 495 Huawei Technologies 496 China 498 Email: lizhenbin@huawei.com