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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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-17) exists of draft-ietf-ippm-ioam-data-01 Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 ippm S. Bhandari 3 Internet-Draft F. Brockners 4 Intended status: Standards Track C. Pignataro 5 Expires: March 22, 2021 Cisco 6 H. Gredler 7 RtBrick Inc. 8 J. Leddy 9 Comcast 10 S. Youell 11 JMPC 12 T. Mizrahi 13 Huawei Network.IO Innovation Lab 14 A. Kfir 15 B. Gafni 16 Mellanox Technologies, Inc. 17 P. Lapukhov 18 Facebook 19 M. Spiegel 20 Barefoot Networks, an Intel company 21 S. Krishnan 22 Kaloom 23 R. Asati 24 Cisco 25 M. Smith 26 September 18, 2020 28 In-situ OAM IPv6 Options 29 draft-ietf-ippm-ioam-ipv6-options-03 31 Abstract 33 In-situ Operations, Administration, and Maintenance (IOAM) records 34 operational and telemetry information in the packet while the packet 35 traverses a path between two points in the network. This document 36 outlines how IOAM data fields are encapsulated in IPv6. 38 Status of This Memo 40 This Internet-Draft is submitted in full conformance with the 41 provisions of BCP 78 and BCP 79. 43 Internet-Drafts are working documents of the Internet Engineering 44 Task Force (IETF). Note that other groups may also distribute 45 working documents as Internet-Drafts. The list of current Internet- 46 Drafts is at https://datatracker.ietf.org/drafts/current/. 48 Internet-Drafts are draft documents valid for a maximum of six months 49 and may be updated, replaced, or obsoleted by other documents at any 50 time. It is inappropriate to use Internet-Drafts as reference 51 material or to cite them other than as "work in progress." 53 This Internet-Draft will expire on March 22, 2021. 55 Copyright Notice 57 Copyright (c) 2020 IETF Trust and the persons identified as the 58 document authors. All rights reserved. 60 This document is subject to BCP 78 and the IETF Trust's Legal 61 Provisions Relating to IETF Documents 62 (https://trustee.ietf.org/license-info) in effect on the date of 63 publication of this document. Please review these documents 64 carefully, as they describe your rights and restrictions with respect 65 to this document. Code Components extracted from this document must 66 include Simplified BSD License text as described in Section 4.e of 67 the Trust Legal Provisions and are provided without warranty as 68 described in the Simplified BSD License. 70 Table of Contents 72 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 73 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3 74 2.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 75 2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 3 76 3. In-situ OAM Metadata Transport in IPv6 . . . . . . . . . . . 3 77 4. IOAM Deployment In IPv6 Networks . . . . . . . . . . . . . . 6 78 4.1. Considerations for IOAM deployment in IPv6 networks . . . 6 79 4.2. IOAM domains bounded by hosts . . . . . . . . . . . . . . 7 80 4.3. IOAM domains bounded by network devices . . . . . . . . . 7 81 4.4. Deployment options . . . . . . . . . . . . . . . . . . . 7 82 4.4.1. IPv6-in-IPv6 encapsulation . . . . . . . . . . . . . 7 83 4.4.2. IP-in-IPv6 encapsulation with ULA . . . . . . . . . . 8 84 4.4.3. x-in-IPv6 Encapsulation that is used Independently . 9 85 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 86 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 87 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 88 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 89 8.1. Normative References . . . . . . . . . . . . . . . . . . 10 90 8.2. Informative References . . . . . . . . . . . . . . . . . 10 91 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 93 1. Introduction 95 In-situ Operations, Administration, and Maintenance (IOAM) records 96 operational and telemetry information in the packet while the packet 97 traverses a path between two points in the network. This document 98 outlines how IOAM data fields are encapsulated in the IPv6 [RFC8200] 99 and discusses deployment options for networks which leverage IOAM 100 data fields encapsulated in the IPv6 protocol. Deployment 101 considerations differ, whether the IOAM domain starts and ends on 102 hosts or whether the IOAM encapsulating and decapsulating nodes are 103 network devices that forward traffic, such as routers. 105 2. Conventions 107 2.1. Requirements Language 109 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 110 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 111 "OPTIONAL" in this document are to be interpreted as described in BCP 112 14 [RFC2119] [RFC8174] when, and only when, they appear in all 113 capitals, as shown here. 115 2.2. Abbreviations 117 Abbreviations used in this document: 119 E2E: Edge-to-Edge 121 IOAM: In-situ Operations, Administration, and Maintenance 123 ION: IOAM Overlay Network 125 OAM: Operations, Administration, and Maintenance 127 POT: Proof of Transit 129 3. In-situ OAM Metadata Transport in IPv6 131 In-situ OAM in IPv6 is used to enhance diagnostics of IPv6 networks. 132 It complements other mechanisms proposed to enhance diagnostics of 133 IPv6 networks, such as the IPv6 Performance and Diagnostic Metrics 134 Destination Option described in [RFC8250]. 136 IOAM data fields are encapsulated in "option data" fields of two 137 types of extension headers in IPv6 packets - either Hop-by-Hop 138 Options header or Destination options header. The selection of a 139 particular extension header type depends on IOAM usage, as described 140 in section 4 of [I-D.ietf-ippm-ioam-data]. Multiple options with the 141 same Option Type MAY appear in the same Hop-by-Hop Options or 142 Destination Options header, with varying content. 144 In order for IOAM to work in IPv6 networks, IOAM MUST be explicitly 145 enabled per interface on every node within the IOAM domain. Unless a 146 particular interface is explicitly enabled (i.e. explicitly 147 configured) for IOAM, a router MUST drop packets which contain 148 extension headers carrying IOAM data-fields. This is the default 149 behavior and is independent of whether the Hop-by-Hop options or 150 Destination options are used to encode the IOAM data. This ensures 151 that IOAM data does not unintentionally get forwarded outside the 152 IOAM domain. 154 An IPv6 packet carrying IOAM data in an Extension header can have 155 other extension headers, compliant with [RFC8200]. 157 IPv6 Hop-by-Hop and Destination Option format for carrying in-situ 158 OAM data fields: 160 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 161 | Option Type | Opt Data Len | Reserved | IOAM Type | 162 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+ 163 | | | 164 . . I 165 . . O 166 . . A 167 . . M 168 . . . 169 . Option Data . O 170 . . P 171 . . T 172 . . I 173 . . O 174 . . N 175 | | | 176 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+ 178 Option Type: 8-bit option type identifier as defined inSection 6. 180 Opt Data Len: 8-bit unsigned integer. Length of this option, in 181 octets, not including the first 2 octets. 183 Reserved: 8-bit field MUST be set to zero upon transmission and 184 ignored upon reception. 186 IOAM Type: 8-bit field as defined in section 7.2 in 187 [I-D.ietf-ippm-ioam-data]. 189 Option Data: Variable-length field. Option-Type-specific data. 191 In-situ OAM Options are inserted as Option data as follows: 193 1. Pre-allocated Trace Option: The in-situ OAM Preallocated Trace 194 option defined in [I-D.ietf-ippm-ioam-data] is represented as an 195 IPv6 option in Hop-by-Hop extension header: 197 Option Type: 001xxxxx 8-bit identifier of the IOAM type of 198 option. xxxxx=TBD. 200 IOAM Type: IOAM Pre-allocated Trace Option Type. 202 2. Incremental Trace Option: The in-situ OAM Incremental Trace 203 option defined in [I-D.ietf-ippm-ioam-data] is represented as an 204 IPv6 option in Hop-by-Hop extension header: 206 Option Type: 001xxxxx 8-bit identifier of the IOAM type of 207 option. xxxxx=TBD. 209 IOAM Type: IOAM Incremental Trace Option Type. 211 3. Proof of Transit Option: The in-situ OAM POT option defined in 212 [I-D.ietf-ippm-ioam-data] is represented as an IPv6 option in 213 Hop-by-Hop extension header: 215 Option Type: 001xxxxx 8-bit identifier of the IOAM type of 216 option. xxxxx=TBD. 218 IOAM Type: IOAM POT Option Type. 220 4. Edge to Edge Option: The in-situ OAM E2E option defined in 221 [I-D.ietf-ippm-ioam-data] is represented as an IPv6 option in 222 Destination extension header: 224 Option Type: 000xxxxx 8-bit identifier of the IOAM type of 225 option. xxxxx=TBD. 227 IOAM Type: IOAM E2E Option Type. 229 All the in-situ OAM IPv6 options defined here have alignment 230 requirements. Specifically, they all require 4n alignment. This 231 ensures that fields specified in [I-D.ietf-ippm-ioam-data] are 232 aligned at a multiple-of-4 offset from the start of the Hop-by-Hop 233 and Destination Options header. In addition, to maintain IPv6 234 extension header 8-octet alignment and avoid the need to add or 235 remove padding at every hop, the Trace-Type for Incremental Trace 236 Option in IPv6 MUST be selected such that the IOAM node data length 237 is a multiple of 8-octets. 239 4. IOAM Deployment In IPv6 Networks 241 4.1. Considerations for IOAM deployment in IPv6 networks 243 IOAM deployment in an IPv6 network should take the following 244 considerations and requirements into account: 246 C1 It is desirable that the addition of IOAM data fields neither 247 changes the way routers forward the packets, nor the forwarding 248 decision the routers takes. The packet with the added OAM 249 information should follow the same path within the domain that the 250 same packet without the OAM information would follow within the 251 domain even in the presence of ECMP. Such a behavior is 252 particularly interesting for deployments where IOAM data fields 253 are only added "on-demand", e.g. to provide further insights in 254 case of undesired network behavior for certain flows. 255 Implementations of IOAM should ensure that ECMP behavior for 256 packets with and without IOAM data fields is the same. 258 C2 Given that IOAM data fields increase the total size of the packet, 259 the size of the packet including the IOAM data could exceed the 260 PMTU. In particular, the incremental trace IOAM HbH Option, which 261 is proposed to support hardware implementations of IOAM, changes 262 Option Data Length en-route. Operators of an IOAM domain are to 263 ensure that the addition of OAM information does not lead to 264 fragmentation of the packet, e.g. by configuring the MTU of 265 transit routers and switches to a sufficiently high value. 266 Careful control of the MTU in a network is one of the reasons why 267 IOAM is considered a domain specific feature, see also 268 [I-D.ietf-ippm-ioam-data]. In addition, the PMTU tolerance range 269 in the IOAM domain should be identified (e.g. through 270 configuration) and IOAM encapsulation operations and/or IOAM data 271 field insertion (in case of incremental tracing) should not be 272 performed if it exceeds the packet size beyond PMTU. 274 C3 Packets with IOAM data or associated ICMP errors, should not 275 arrive at destinations which have no knowledge of IOAM. Consider 276 using IOAM in transit devices; misleading ICMP errors due to 277 addition and/or presence of OAM data in the packet can confuse a 278 source of the packet that did not insert the OAM information. 280 C4 OAM data leaks may affect the forwarding behavior and state of 281 network elements outside an IOAM domain. IOAM domains SHOULD 282 provide a mechanism to prevent data leaks or be able to assure 283 that upon leak network elements outside the domain are not 284 affected i.e they continue to process other valid packets. 286 C5 The source of that inserted and leaked the IOAM data must be easy 287 to identify for the purpose of troubleshooting, due to the high 288 complexity of troubleshooting a source that inserted the IOAM data 289 and did not remove it when the packet traversed across an AS. 290 Such a troubleshooting process may require coordination between 291 multiple operators, complicated configuration verification, packet 292 capture analysis, etc. 294 C6 Compliance with [RFC8200] would require OAM data to be 295 encapsulated instead of header/option insertion directly into in- 296 flight packets using the original IPv6 header. 298 4.2. IOAM domains bounded by hosts 300 For deployments where the IOAM domain is bounded by hosts, hosts will 301 perform the operation of IOAM data field encapsulation and 302 decapsulation. IOAM data is carried in IPv6 packets as Hop-by-Hop or 303 Destination options as specified in this document. 305 4.3. IOAM domains bounded by network devices 307 For deployments where the IOAM domain is bounded by network devices, 308 network devices such as routers form the edge of an IOAM domain. 309 Network devices will perform the operation of IOAM data field 310 encapsulation and decapsulation. 312 4.4. Deployment options 314 This section lists out possible deployment options that can be 315 employed to meet the requirements listed in Section 4.1. 317 4.4.1. IPv6-in-IPv6 encapsulation 319 Leverage an IPv6-in-IPv6 approach: Preserve the original IP packet 320 and add an IPv6 header including IOAM data fields in an extension 321 header in front of it, to forward traffic within and across the IOAM 322 domain. The overlay network formed by the additional IPv6 header 323 with the IOAM data fields included in an extension header is referred 324 to as IOAM Overlay Network (ION) in this document. 326 1. Perform an IPv6-in-IPv6 approach. The source address of the 327 outer IPv6 header is that of the IOAM encapsulating node. The 328 destination address of the outer IPv6 header is the same as the 329 inner IPv6 destination address, i.e. the destination address of 330 the packet does not change. 332 2. To simplify debugging in case of leaked IOAM data fields in 333 packets, consider a new IOAM E2E destination option to identify 334 the Source IOAM domain (AS, v6 prefix). Insert this option into 335 the IOAM destination options EH attached to the outer IPv6 336 header. This additional information would allow for easy 337 identification of an AS operator that is the source of packets 338 with leaked IOAM information. Note that leaked packets with IOAM 339 data fields would only occur in case a router would be 340 misconfigured. 342 3. All the IOAM options are defined with type "00 - skip over this 343 option and continue processing the header. So presence of the 344 options must not cause packet drop in the network elements that 345 do not understand the option. In addition 346 [I-D.ietf-6man-hbh-header-handling] should be considered. 348 4.4.2. IP-in-IPv6 encapsulation with ULA 350 The "IP-in-IPv6 encapsulation with ULA" [RFC4193] approach can be 351 used to apply IOAM to an IPv6 as well as an IPv4 network. In 352 addition, it fulfills requirement C4 (avoid leaks) by using ULA for 353 the ION. Similar to the IPv6-in-IPv6 encapsulation approach above, 354 the original IP packet is preserved. An IPv6 header including IOAM 355 data fields in an extension header is added in front of it, to 356 forward traffic within and across the IOAM domain. IPv6 addresses 357 for the ION, i.e. the outer IPv6 addresses are assigned from the ULA 358 space. Addressing and routing in the ION are to be configured so 359 that the IP-in-IPv6 encapsulated packets follow the same path as the 360 original, non-encapsulated packet would have taken. This would 361 create an internal IPv6 forwarding topology using the IOAM domain's 362 interior ULA address space which is parallel with the forwarding 363 topology that exists with the non-IOAM address space (the topology 364 and address space that would be followed by packets that do not have 365 supplemental IOAM information). Establishment and maintenance of the 366 parallel IOAM ULA forwarding topology could be automated, e.g. 367 similar to how LDP [RFC5036] is used in MPLS to establish and 368 maintain an LSP forwarding topology that is parallel to the network's 369 IGP forwarding topology. 371 Transit across the ION could leverage the transit approach for 372 traffic between BGP border routers, as described in [RFC1772], "A.2.3 373 Encapsulation". Assuming that the operational guidelines specified 374 in Section 4 of [RFC4193] are properly followed, the probability of 375 leaks in this approach will be almost close to zero. If the packets 376 do leak through IOAM egress device misconfiguration or partial IOAM 377 egress device failure, the packets' ULA destination address is 378 invalid outside of the IOAM domain. There is no exterior destination 379 to be reached, and the packets will be dropped when they encounter 380 either a router external to the IOAM domain that has a packet filter 381 that drops packets with ULA destinations, or a router that does not 382 have a default route. 384 4.4.3. x-in-IPv6 Encapsulation that is used Independently 386 In some cases it is desirable to monitor a domain that uses an 387 overlay network that is deployed independently of the need for IOAM, 388 e.g., an overlay network that runs Geneve-in-IPv6, or VXLAN-in-IPv6. 389 In this case IOAM can be encapsulated in as an extension header in 390 the tunnel (outer) IPv6 header. Thus, the tunnel encapsulating node 391 is also the IOAM encapsulating node, and the tunnel end point is also 392 the IOAM decapsulating node. 394 5. Security Considerations 396 This document describes the encapsulation of IOAM data fields in 397 IPv6. Security considerations of the specific IOAM data fields for 398 each case (i.e., Trace, Proof of Transit, and E2E) are described and 399 defined in [I-D.ietf-ippm-ioam-data]. 401 As this document describes new options for IPv6, these are similar to 402 the security considerations of [RFC8200] and the new weakness 403 documented in [RFC8250]. 405 6. IANA Considerations 407 This draft requests the following IPv6 Option Type assignments from 408 the Destination Options and Hop-by-Hop Options sub-registry of 409 Internet Protocol Version 6 (IPv6) Parameters. 411 http://www.iana.org/assignments/ipv6-parameters/ipv6- 412 parameters.xhtml#ipv6-parameters-2 414 Hex Value Binary Value Description Reference 415 act chg rest 416 ---------------------------------------------------------------- 417 TBD_1_0 00 0 TBD_1 IOAM [This draft] 418 TBD_1_1 00 1 TBD_1 IOAM [This draft] 420 7. Acknowledgements 422 The authors would like to thank Tom Herbert, Eric Vyncke, Nalini 423 Elkins, Srihari Raghavan, Ranganathan T S, Karthik Babu Harichandra 424 Babu, Akshaya Nadahalli, Stefano Previdi, Hemant Singh, Erik 425 Nordmark, LJ Wobker, Mark Smith, Andrew Yourtchenko and Justin Iurman 426 for the comments and advice. For the IPv6 encapsulation, this 427 document leverages concepts described in 428 [I-D.kitamura-ipv6-record-route]. The authors would like to 429 acknowledge the work done by the author Hiroshi Kitamura and people 430 involved in writing it. 432 8. References 434 8.1. Normative References 436 [I-D.ietf-ippm-ioam-data] 437 Brockners, F., Bhandari, S., Pignataro, C., Gredler, H., 438 Leddy, J., Youell, S., Mizrahi, T., Mozes, D., Lapukhov, 439 P., Chang, R., and d. daniel.bernier@bell.ca, "Data Fields 440 for In-situ OAM", draft-ietf-ippm-ioam-data-01 (work in 441 progress), October 2017. 443 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 444 Requirement Levels", BCP 14, RFC 2119, 445 DOI 10.17487/RFC2119, March 1997, 446 . 448 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 449 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 450 May 2017, . 452 8.2. Informative References 454 [I-D.ietf-6man-hbh-header-handling] 455 Baker, F. and R. Bonica, "IPv6 Hop-by-Hop Options 456 Extension Header", March 2016. 458 [I-D.kitamura-ipv6-record-route] 459 Kitamura, H., "Record Route for IPv6 (PR6) Hop-by-Hop 460 Option Extension", draft-kitamura-ipv6-record-route-00 461 (work in progress), November 2000. 463 [RFC1772] Rekhter, Y. and P. Gross, "Application of the Border 464 Gateway Protocol in the Internet", RFC 1772, 465 DOI 10.17487/RFC1772, March 1995, 466 . 468 [RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast 469 Addresses", RFC 4193, DOI 10.17487/RFC4193, October 2005, 470 . 472 [RFC5036] Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed., 473 "LDP Specification", RFC 5036, DOI 10.17487/RFC5036, 474 October 2007, . 476 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 477 (IPv6) Specification", STD 86, RFC 8200, 478 DOI 10.17487/RFC8200, July 2017, 479 . 481 [RFC8250] Elkins, N., Hamilton, R., and M. Ackermann, "IPv6 482 Performance and Diagnostic Metrics (PDM) Destination 483 Option", RFC 8250, DOI 10.17487/RFC8250, September 2017, 484 . 486 Authors' Addresses 488 Shwetha Bhandari 489 Cisco Systems, Inc. 490 Cessna Business Park, Sarjapura Marathalli Outer Ring Road 491 Bangalore, KARNATAKA 560 087 492 India 494 Email: shwethab@cisco.com 496 Frank Brockners 497 Cisco Systems, Inc. 498 Kaiserswerther Str. 115, 499 RATINGEN, NORDRHEIN-WESTFALEN 40880 500 Germany 502 Email: fbrockne@cisco.com 504 Carlos Pignataro 505 Cisco Systems, Inc. 506 7200-11 Kit Creek Road 507 Research Triangle Park, NC 27709 508 United States 510 Email: cpignata@cisco.com 512 Hannes Gredler 513 RtBrick Inc. 515 Email: hannes@rtbrick.com 516 John Leddy 517 Comcast 519 Email: John_Leddy@cable.comcast.com 521 Stephen Youell 522 JP Morgan Chase 523 25 Bank Street 524 London E14 5JP 525 United Kingdom 527 Email: stephen.youell@jpmorgan.com 529 Tal Mizrahi 530 Huawei Network.IO Innovation Lab 531 Israel 533 Email: tal.mizrahi.phd@gmail.com 535 Aviv Kfir 536 Mellanox Technologies, Inc. 537 350 Oakmead Parkway, Suite 100 538 Sunnyvale, CA 94085 539 U.S.A. 541 Email: avivk@mellanox.com 543 Barak Gafni 544 Mellanox Technologies, Inc. 545 350 Oakmead Parkway, Suite 100 546 Sunnyvale, CA 94085 547 U.S.A. 549 Email: gbarak@mellanox.com 551 Petr Lapukhov 552 Facebook 553 1 Hacker Way 554 Menlo Park, CA 94025 555 US 557 Email: petr@fb.com 558 Mickey Spiegel 559 Barefoot Networks, an Intel company 560 4750 Patrick Henry Drive 561 Santa Clara, CA 95054 562 US 564 Email: mickey.spiegel@intel.com 566 Suresh Krishnan 567 Kaloom 569 Email: suresh@kaloom.com 571 Rajiv Asati 572 Cisco Systems, Inc. 573 7200 Kit Creek Road 574 Research Triangle Park, NC 27709 575 US 577 Email: rajiva@cisco.com 579 Mark Smith 580 PO BOX 521 581 HEIDELBERG, VIC 3084 582 AU 584 Email: markzzzsmith+id@gmail.com