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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: 'RFC2784' is defined on line 312, but no explicit reference was found in the text == Unused Reference: 'RFC3232' is defined on line 317, but no explicit reference was found in the text == Outdated reference: A later version (-17) exists of draft-ietf-ippm-ioam-data-09 ** Downref: Normative reference to an Informational RFC: RFC 3232 Summary: 1 error (**), 0 flaws (~~), 4 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 ippm F. Brockners 3 Internet-Draft S. Bhandari 4 Intended status: Standards Track V. Govindan 5 Expires: September 30, 2020 C. Pignataro 6 Cisco 7 H. Gredler 8 RtBrick Inc. 9 J. Leddy 11 S. Youell 12 JMPC 13 T. Mizrahi 14 Huawei Network.IO Innovation Lab 15 P. Lapukhov 16 Facebook 17 B. Gafni 18 A. Kfir 19 Mellanox Technologies, Inc. 20 M. Spiegel 21 Barefoot Networks, an Intel company 22 May 13, 2020 24 Geneve encapsulation for In-situ OAM Data 25 draft-brockners-ippm-ioam-geneve-04 27 Abstract 29 In-situ Operations, Administration, and Maintenance (IOAM) records 30 operational and telemetry information in the packet while the packet 31 traverses a path between two points in the network. This document 32 proposes a new Geneve tunnel option and outlines how IOAM data fields 33 are carried in the option data field. 35 Status of This Memo 37 This Internet-Draft is submitted in full conformance with the 38 provisions of BCP 78 and BCP 79. 40 Internet-Drafts are working documents of the Internet Engineering 41 Task Force (IETF). Note that other groups may also distribute 42 working documents as Internet-Drafts. The list of current Internet- 43 Drafts is at https://datatracker.ietf.org/drafts/current/. 45 Internet-Drafts are draft documents valid for a maximum of six months 46 and may be updated, replaced, or obsoleted by other documents at any 47 time. It is inappropriate to use Internet-Drafts as reference 48 material or to cite them other than as "work in progress." 49 This Internet-Draft will expire on September 30, 2020. 51 Copyright Notice 53 Copyright (c) 2020 IETF Trust and the persons identified as the 54 document authors. All rights reserved. 56 This document is subject to BCP 78 and the IETF Trust's Legal 57 Provisions Relating to IETF Documents 58 (https://trustee.ietf.org/license-info) in effect on the date of 59 publication of this document. Please review these documents 60 carefully, as they describe your rights and restrictions with respect 61 to this document. Code Components extracted from this document must 62 include Simplified BSD License text as described in Section 4.e of 63 the Trust Legal Provisions and are provided without warranty as 64 described in the Simplified BSD License. 66 Table of Contents 68 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 69 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3 70 2.1. Requirement Language . . . . . . . . . . . . . . . . . . 3 71 2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 3 72 3. IOAM Data Field Encapsulation in Geneve . . . . . . . . . . . 3 73 4. Considerations . . . . . . . . . . . . . . . . . . . . . . . 5 74 4.1. Discussion of the encapsulation approach . . . . . . . . 5 75 4.2. IOAM and the use of the Geneve O-bit . . . . . . . . . . 6 76 4.3. Transit devices . . . . . . . . . . . . . . . . . . . . . 6 77 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 78 6. Security Considerations . . . . . . . . . . . . . . . . . . . 7 79 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 80 8. Normative References . . . . . . . . . . . . . . . . . . . . 7 81 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 83 1. Introduction 85 In-situ OAM (IOAM) records OAM information within the packet while 86 the packet traverses a particular network domain. The term "in-situ" 87 refers to the fact that the IOAM data fields are added to the data 88 packets rather than is being sent within packets specifically 89 dedicated to OAM. This document proposes a new Geneve tunnel option 90 and defines how IOAM data fields are transported as part of the 91 tunnel option in the Geneve [I-D.ietf-nvo3-geneve] encapsulation. 92 The IOAM data fields are defined in [I-D.ietf-ippm-ioam-data]. 94 2. Conventions 96 2.1. Requirement Language 98 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 99 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 100 document are to be interpreted as described in [RFC2119]. 102 2.2. Abbreviations 104 Abbreviations used in this document: 106 IOAM: In-situ Operations, Administration, and Maintenance 108 OAM: Operations, Administration, and Maintenance 110 Geneve: Generic Network Virtualization Encapsulation 112 3. IOAM Data Field Encapsulation in Geneve 114 Geneve is defined in [I-D.ietf-nvo3-geneve]. IOAM data fields are 115 carried in the Geneve header as a tunnel option, using a single 116 Geneve Option Class TBD_IOAM. The different IOAM data fields defined 117 in [I-D.ietf-ippm-ioam-data] are added as TLVs using that Geneve 118 Option Class. In an administrative domain where IOAM is used, 119 insertion of the IOAM header in Geneve is enabled at the Geneve 120 tunnel endpoints, which also serve as IOAM encapsulating/ 121 decapsulating nodes by means of configuration. 123 0 1 2 3 124 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 1 125 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+ 126 |Ver| Opt Len |O|C| Rsvd. | Protocol Type | | 127 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Hdr 128 | Virtual Network Identifier (VNI) | Reserved | | 129 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+ 130 | Option Class = TBD_IOAM | Type |R|R|R| Length | | 131 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ I 132 ! | O 133 ! | A 134 ~ IOAM Option and Data Space ~ M 135 | | | 136 | | | 137 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+ 138 | | 139 | | 140 | Payload + Padding (L2/L3/ESP/...) | 141 | | 142 | | 143 | | 144 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 146 Figure 1: IOAM data encapsulation in Geneve 148 The Geneve header and fields are defined in [I-D.ietf-nvo3-geneve]. 149 The Geneve Option Class value for use with IOAM is TBD_IOAM. 151 The fields related to the encapsulation of IOAM data fields in Geneve 152 are defined as follows: 154 Option Class: 16-bit unsigned integer that determines the IOAM 155 option class. The value is from the IANA registry setup for 156 Geneve option classes as defined in [I-D.ietf-nvo3-geneve]. 158 Type: 8-bit field defining the IOAM Option type, as defined in 159 Section 7.2 of [I-D.ietf-ippm-ioam-data]. 161 R (3 bits): Option control flags reserved for future use. The flags 162 MUST be set to zero on transmission and ignored on receipt. 164 Length: 5-bit unsigned integer. Length of the IOAM HDR in 4-octet 165 units. 167 IOAM Option and Data Space: IOAM option header and data is present 168 as defined by the Type field, and is defined in Section 4 of 169 [I-D.ietf-ippm-ioam-data]. 171 Multiple distinct IOAM Option-Types MAY be included within the same 172 Geneve encapsulation. Each IOAM Option-Type MUST occur at most once 173 within the same Geneve encapsulation. For example, if a Geneve 174 encapsulation contains two IOAM Option-Types before a data payload, 175 there would be two fields with TBD_IOAM Option Class each, 176 differentiated by the Type field which specifies the type of the IOAM 177 data included. 179 4. Considerations 181 This section summarizes a set of considerations on the overall 182 approach taken for IOAM data encapsulation in Geneve, as well as 183 deployment considerations. 185 4.1. Discussion of the encapsulation approach 187 This section is to support the working group discussion in selecting 188 the most appropriate approach for encapsulating IOAM data fields in 189 Geneve. 191 An encapsulation of IOAM data fields in Geneve should be friendly to 192 an implementation in both hardware as well as software forwarders and 193 support a wide range of deployment cases, including large networks 194 that desire to leverage multiple IOAM data fields at the same time. 196 Hardware and software friendly implementation: Hardware forwarders 197 benefit from an encapsulation that minimizes iterative look-ups of 198 fields within the packet: Any operation which looks up the value 199 of a field within the packet, based on which another lookup is 200 performed, consumes additional gates and time in an implementation 201 - both of which are desired to be kept to a minimum. This means 202 that flat TLV structures are to be preferred over nested TLV 203 structures. IOAM data fields are grouped into three option 204 categories: Trace, proof-of-transit, and edge-to-edge. Each of 205 these three options defines a TLV structure. A hardware-friendly 206 encapsulation approach avoids grouping these three option 207 categories into yet another TLV structure, but would rather carry 208 the options as a serial sequence. 210 Total length of the IOAM data fields: The total length of IOAM 211 data can grow quite large in case multiple different IOAM data 212 fields are used and large path-lengths need to be considered. If 213 for example an operator would consider using the IOAM trace option 214 and capture node-id, app_data, egress/ingress interface-id, 215 timestamp seconds, timestamps nanoseconds at every hop, then a 216 total of 20 octets would be added to the packet at every hop. In 217 case this particular deployment would have a maximum path length 218 of 15 hops in the IOAM domain, then a maximum of 300 octets of 219 IOAM data were to be encapsulated in the packet. 221 Concerns with the current encapsulation approach: 223 Hardware support: Using Geneve tunnel options to encapsulate IOAM 224 data fields leads to a nested TLV structure. Each IOAM data field 225 option (trace, proof-of-transit, and edge-to-edge) represents a 226 type, with the different IOAM data fields being TLVs within this 227 the particular option type. Nested TLVs require iterative look- 228 ups, a fact that creates potential challenges for implementations 229 in hardware. It would be desirable to offer a way to encapsulate 230 IOAM in a way that keeps TLV nesting to a minimum. 232 Length: Geneve tunnel option length is a 5-bit field in the 233 current specification [I-D.ietf-nvo3-geneve] resulting in a 234 maximum option length of 128 (2^5 x 4) octets which constrains the 235 use of IOAM to either small domains or a few IOAM data fields 236 only. Support for large domains with a variety of IOAM data 237 fields would be desirable. 239 4.2. IOAM and the use of the Geneve O-bit 241 [I-D.ietf-nvo3-geneve] defines an "O bit" for OAM packets. Per 242 [I-D.ietf-nvo3-geneve] the O bit indicates that the packet contains a 243 control message instead of data payload. Packets that carry IOAM 244 data fields in addition to regular data payload / customer traffic 245 must not set the O bit. Packets that carry only IOAM data fields 246 without any payload must set the O bit. 248 4.3. Transit devices 250 If IOAM is deployed in domains where UDP port numbers are not 251 controlled and do not have a domain-wide meaning, such as on the 252 global Internet, transit devices MUST NOT attempt to modify the IOAM 253 data contained in the IOAM option class. In case UDP port numbers 254 are not controlled there might be UDP packets, which leverage the UDP 255 port number that Geneve utilizes, i.e. 6081, but the payload of these 256 packets isn't Geneve. The scenario and associated reasoning is 257 discussed in [RFC7605] which states that "it is important to 258 recognize that any interpretation of port numbers -- except at the 259 endpoints -- may be incorrect, because port numbers are meaningful 260 only at the endpoints." 262 5. IANA Considerations 264 IANA is requested to allocate a Geneve "option class" numbers for 265 IOAM: 267 +---------------+-------------+---------------+ 268 | Option Class | Description | Reference | 269 +---------------+-------------+---------------+ 270 | x | TBD_IOAM | This document | 271 +---------------+-------------+---------------+ 273 6. Security Considerations 275 The security considerations of Geneve are discussed in 276 [I-D.ietf-nvo3-geneve], and the security considerations of IOAM in 277 general are discussed in [I-D.ietf-ippm-ioam-data]. 279 IOAM is considered a "per domain" feature, where one or several 280 operators decide on leveraging and configuring IOAM according to 281 their needs. Still, operators need to properly secure the IOAM 282 domain to avoid malicious configuration and use, which could include 283 injecting malicious IOAM packets into a domain. 285 7. Acknowledgements 287 The authors would like to thank Eric Vyncke, Nalini Elkins, Srihari 288 Raghavan, Ranganathan T S, Karthik Babu Harichandra Babu, Akshaya 289 Nadahalli, Stefano Previdi, Hemant Singh, Erik Nordmark, LJ Wobker, 290 Andrew Yourtchenko and Nagendra Kumar Nainar for the comments and 291 advice. 293 8. Normative References 295 [I-D.ietf-ippm-ioam-data] 296 Brockners, F., Bhandari, S., Pignataro, C., Gredler, H., 297 Leddy, J., Youell, S., Mizrahi, T., Mozes, D., Lapukhov, 298 P., remy@barefootnetworks.com, r., daniel.bernier@bell.ca, 299 d., and J. Lemon, "Data Fields for In-situ OAM", draft- 300 ietf-ippm-ioam-data-09 (work in progress), March 2020. 302 [I-D.ietf-nvo3-geneve] 303 Gross, J., Ganga, I., and T. Sridhar, "Geneve: Generic 304 Network Virtualization Encapsulation", draft-ietf- 305 nvo3-geneve-16 (work in progress), March 2020. 307 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 308 Requirement Levels", BCP 14, RFC 2119, 309 DOI 10.17487/RFC2119, March 1997, 310 . 312 [RFC2784] Farinacci, D., Li, T., Hanks, S., Meyer, D., and P. 313 Traina, "Generic Routing Encapsulation (GRE)", RFC 2784, 314 DOI 10.17487/RFC2784, March 2000, 315 . 317 [RFC3232] Reynolds, J., Ed., "Assigned Numbers: RFC 1700 is Replaced 318 by an On-line Database", RFC 3232, DOI 10.17487/RFC3232, 319 January 2002, . 321 [RFC7605] Touch, J., "Recommendations on Using Assigned Transport 322 Port Numbers", BCP 165, RFC 7605, DOI 10.17487/RFC7605, 323 August 2015, . 325 Authors' Addresses 327 Frank Brockners 328 Cisco Systems, Inc. 329 Hansaallee 249, 3rd Floor 330 DUESSELDORF, NORDRHEIN-WESTFALEN 40549 331 Germany 333 Email: fbrockne@cisco.com 335 Shwetha Bhandari 336 Cisco Systems, Inc. 337 Cessna Business Park, Sarjapura Marathalli Outer Ring Road 338 Bangalore, KARNATAKA 560 087 339 India 341 Email: shwethab@cisco.com 343 Vengada Prasad Govindan 344 Cisco Systems, Inc. 346 Email: venggovi@cisco.com 347 Carlos Pignataro 348 Cisco Systems, Inc. 349 7200-11 Kit Creek Road 350 Research Triangle Park, NC 27709 351 United States 353 Email: cpignata@cisco.com 355 Hannes Gredler 356 RtBrick Inc. 358 Email: hannes@rtbrick.com 360 John Leddy 361 United States 363 Email: john@leddy.net 365 Stephen Youell 366 JP Morgan Chase 367 25 Bank Street 368 London E14 5JP 369 United Kingdom 371 Email: stephen.youell@jpmorgan.com 373 Tal Mizrahi 374 Huawei Network.IO Innovation Lab 375 Israel 377 Email: tal.mizrahi.phd@gmail.com 379 Petr Lapukhov 380 Facebook 381 1 Hacker Way 382 Menlo Park, CA 94025 383 US 385 Email: petr@fb.com 386 Barak Gafni 387 Mellanox Technologies, Inc. 388 350 Oakmead Parkway, Suite 100 389 Sunnyvale, CA 94085 390 U.S.A. 392 Email: gbarak@mellanox.com 394 Aviv Kfir 395 Mellanox Technologies, Inc. 396 350 Oakmead Parkway, Suite 100 397 Sunnyvale, CA 94085 398 U.S.A. 400 Email: avivk@mellanox.com 402 Mickey Spiegel 403 Barefoot Networks, an Intel company 404 4750 Patrick Henry Drive 405 Santa Clara, CA 95054 406 US 408 Email: mickey.spiegel@intel.com