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Mirsky 4 Intended status: Informational ZTE 5 Expires: January 9, 2020 July 8, 2019 7 BFD for Geneve 8 draft-xiao-nvo3-bfd-geneve-00 10 Abstract 12 This document describes the use of the Bidirectional Forwarding 13 Detection (BFD) protocol in point-to-point Generic Network 14 Virtualization Encapsulation (Geneve) tunnels forming up an overlay 15 network. 17 Status of This Memo 19 This Internet-Draft is submitted in full conformance with the 20 provisions of BCP 78 and BCP 79. 22 Internet-Drafts are working documents of the Internet Engineering 23 Task Force (IETF). Note that other groups may also distribute 24 working documents as Internet-Drafts. The list of current Internet- 25 Drafts is at https://datatracker.ietf.org/drafts/current/. 27 Internet-Drafts are draft documents valid for a maximum of six months 28 and may be updated, replaced, or obsoleted by other documents at any 29 time. It is inappropriate to use Internet-Drafts as reference 30 material or to cite them other than as "work in progress." 32 This Internet-Draft will expire on January 9, 2020. 34 Copyright Notice 36 Copyright (c) 2019 IETF Trust and the persons identified as the 37 document authors. All rights reserved. 39 This document is subject to BCP 78 and the IETF Trust's Legal 40 Provisions Relating to IETF Documents 41 (https://trustee.ietf.org/license-info) in effect on the date of 42 publication of this document. Please review these documents 43 carefully, as they describe your rights and restrictions with respect 44 to this document. Code Components extracted from this document must 45 include Simplified BSD License text as described in Section 4.e of 46 the Trust Legal Provisions and are provided without warranty as 47 described in the Simplified BSD License. 49 Table of Contents 51 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 52 2. Conventions Used in This Document . . . . . . . . . . . . . . 2 53 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2 54 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 55 3. BFD Packet Transmission over Geneve Tunnel . . . . . . . . . 3 56 3.1. BFD Encapsulation With Inner Ethernet/IP/UDP Header . . . 3 57 3.2. BFD Encapsulation With Inner IP/UDP Header . . . . . . . 5 58 3.3. BFD Encapsulation With Inner MPLS Header . . . . . . . . 7 59 3.4. BFD Encapsulation With Inner OAM Shim . . . . . . . . . . 9 60 4. Reception of BFD packet from Geneve Tunnel . . . . . . . . . 10 61 4.1. Demultiplexing of the BFD packet . . . . . . . . . . . . 11 62 5. Security Considerations . . . . . . . . . . . . . . . . . . . 12 63 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 64 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 65 8. Normative References . . . . . . . . . . . . . . . . . . . . 12 66 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 68 1. Introduction 70 "Generic Network Virtualization Encapsulation" (Geneve) 71 [I-D.ietf-nvo3-geneve] provides an encapsulation scheme that allows 72 building an overlay network by decoupling the address space of the 73 attached virtual hosts from that of the network. 75 This document describes the use of Bidirectional Forwarding Detection 76 (BFD) protocol [RFC5880] to enable monitoring continuity of the path 77 between two Geneve tunnel endpoints, which may be NVE (Network 78 Virtualization Edge) or other device acting as a Geneve tunnel 79 endpoint. For simplicity, in this document, NVE is used to represent 80 Geneve tunnel endpoint, Virtual Machine (VM) is used to represent the 81 device attached to a Geneve tunnel endpoint from the outside. 83 The use cases and the deployment of BFD for Geneve are consistent 84 with what's described in Section 1 and Section 3 of 85 [I-D.ietf-bfd-vxlan]. The major difference between Geneve and 86 "Virtual eXtensible Local Area Network" (VXLAN) [RFC7348] 87 encapsulation is that Geneve supports multi-protocol payload and 88 variable length options. 90 2. Conventions Used in This Document 92 2.1. Terminology 94 BFD: Bidirectional Forwarding Detection 96 CC: Continuity Check 97 GAL: Generic Associated Channel Label 99 G-ACh: Generic Associated Channel 101 Geneve: Generic Network Virtualization Encapsulation 103 MPLS: Multiprotocol Label Switching 105 NVE: Network Virtualization Edge 107 VM: Virtual Machine 109 VNI: Virtual Network Identifier 111 VXLAN: Virtual eXtensible Local Area Network 113 2.2. Requirements Language 115 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 116 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 117 "OPTIONAL" in this document are to be interpreted as described in BCP 118 14 [RFC2119] [RFC8174] when, and only when, they appear in all 119 capitals, as shown here. 121 3. BFD Packet Transmission over Geneve Tunnel 123 Concerning whether or not the Geneve data packets include an IP 124 protocol data unit, and whether or not the Geneve data packets 125 include an MPLS protocol data unit, this document considers four 126 options of BFD packet encapsulation in Geneve. 128 3.1. BFD Encapsulation With Inner Ethernet/IP/UDP Header 130 If the Protocol Type field (as defined in Section 3.4 of 131 [I-D.ietf-nvo3-geneve]) of data packets indicates that there exists 132 an inner Ethernet header, i.e., the Protocol Type equals to 0x6558 133 (Ethernet frame), then BFD packets are encapsulated in Geneve as 134 described below. The Geneve packet format over IPv4 is defined in 135 Section 3.1 of [I-D.ietf-nvo3-geneve]. The Geneve packet format over 136 IPv6 is defined in Section 3.2 of [I-D.ietf-nvo3-geneve]. The Outer 137 IP/UDP and Geneve headers MUST be encoded by the sender as defined in 138 [I-D.ietf-nvo3-geneve]. Note that the outer IP header and the inner 139 IP header may not be of the same address family, in other words, 140 outer IPv6 header accompanied with inner IPv4 header and outer IPv4 141 header accompanied with inner IPv6 header are both possible. 143 0 1 2 3 144 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 1 145 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 146 | | 147 ~ Outer Ethernet Header ~ 148 | | 149 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 150 | | 151 ~ Outer IPvX Header ~ 152 | | 153 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 154 | | 155 ~ Outer UDP Header ~ 156 | | 157 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 158 | | 159 ~ Geneve Header ~ 160 | | 161 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 | | 163 ~ Inner Ethernet Header ~ 164 | | 165 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 166 | | 167 ~ Inner IPvX Header ~ 168 | | 169 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 170 | | 171 ~ Inner UDP Header ~ 172 | | 173 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 174 | | 175 ~ BFD Control Message ~ 176 | | 177 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 178 | FCS | 179 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 181 Figure 1: Geneve Encapsulation of BFD Control Message With the Inner 182 Ethernet/IP/UDP Header 184 The BFD packet MUST be carried inside the inner Ethernet frame of the 185 Geneve packet, as specified in Section 4 of [I-D.ietf-bfd-vxlan]. 187 When the BFD packets are encapsulated in Geneve in this way, the 188 Geneve header follows the value set below. 190 0 1 2 3 191 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 1 192 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 |Ver| Opt Len |O|C| Rsvd. | Protocol Type | 194 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 195 | Virtual Network Identifier (VNI) | Reserved | 196 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 197 | Variable Length Options | 198 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 200 Figure 2: Geneve Header 202 Opt Len field SHOULD be set to 0, which indicates there isn't any 203 variable length option. 205 [Ed.Note]: Use of O bit is still being discussed in the NVO3 WG, so 206 the value is undetermined. 208 C bit MUST be set to 0. 210 Protocol Type field MUST be set to 0x6558 (Ethernet frame). 212 3.2. BFD Encapsulation With Inner IP/UDP Header 214 If the Protocol Type field (as defined in Section 3.4 of 215 [I-D.ietf-nvo3-geneve]) of data packets indicates that there exists 216 an inner IP header, i.e., the Protocol Type equals to 0x0800 (IPv4) 217 or 0x86DD (IPv6), then BFD packets are encapsulated in Geneve as 218 described below. The Geneve packet format over IPv4 is defined in 219 Section 3.1 of [I-D.ietf-nvo3-geneve]. The Geneve packet format over 220 IPv6 is defined in Section 3.2 of [I-D.ietf-nvo3-geneve]. The Outer 221 IP/UDP and Geneve headers MUST be encoded by the sender as defined in 222 [I-D.ietf-nvo3-geneve]. Note that the outer IP header and the inner 223 IP header may not be of the same address family, in other words, 224 outer IPv6 header accompanied with inner IPv4 header and outer IPv4 225 header accompanied with inner IPv6 header are both possible. 227 0 1 2 3 228 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 1 229 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 230 | | 231 ~ Outer Ethernet Header ~ 232 | | 233 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 234 | | 235 ~ Outer IPvX Header ~ 236 | | 237 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 238 | | 239 ~ Outer UDP Header ~ 240 | | 241 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 242 | | 243 ~ Geneve Header ~ 244 | | 245 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 246 | | 247 ~ Inner IPvX Header ~ 248 | | 249 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 250 | | 251 ~ Inner UDP Header ~ 252 | | 253 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 254 | | 255 ~ BFD Control Message ~ 256 | | 257 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 258 | FCS | 259 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 261 Figure 3: Geneve Encapsulation of BFD Control Message With the Inner 262 IP/UDP Header 264 The BFD packet MUST be carried inside the inner IP packet of the 265 Geneve packet. The inner IP packet carrying the BFD payload has the 266 following format: 268 IP header: 270 Source IP: IP address of the VM-facing interface of the 271 originating NVE. 273 Destination IP: IP address of the VM-facing interface of the 274 terminating NVE. 276 TTL: MUST be set to 1 to ensure that the BFD packet is not 277 routed within the L3 underlay network. 279 The fields of the UDP header and the BFD control packet are 280 encoded as specified in [RFC5881]. 282 When the BFD packets are encapsulated in Geneve in this way, the 283 Geneve header follows the value set below. 285 Opt Len field SHOULD be set to 0, which indicates there isn't any 286 variable length option. 288 [Ed.Note]: Use of O bit is still being discussed in the NVO3 WG, so 289 the value is undetermined. 291 C bit MUST be set to 0. 293 Protocol Type field MUST be set to 0x0800 (IPv4) or 0x86DD (IPv6), 294 depending on the address family of the inner IP packet. 296 3.3. BFD Encapsulation With Inner MPLS Header 298 If the Protocol Type field (as defined in Section 3.4 of 299 [I-D.ietf-nvo3-geneve]) of data packets indicates that there exists 300 an inner MPLS header, i.e., the Protocol Type equals to 0x8847 (MPLS) 301 or 0x8848 (MPLS with the upstream-assigned label), then BFD packets 302 are encapsulated in Geneve as described below. The Geneve packet 303 format over IPv4 is defined in Section 3.1 of [I-D.ietf-nvo3-geneve]. 304 The Geneve packet format over IPv6 is defined in Section 3.2 of 305 [I-D.ietf-nvo3-geneve]. The Outer IP/UDP and Geneve headers MUST be 306 encoded by the sender as defined in [I-D.ietf-nvo3-geneve]. 308 0 1 2 3 309 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 1 310 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 311 | | 312 ~ Outer Ethernet Header ~ 313 | | 314 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 315 | | 316 ~ Outer IPvX Header ~ 317 | | 318 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 319 | | 320 ~ Outer UDP Header ~ 321 | | 322 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 323 | | 324 ~ Geneve Header ~ 325 | | 326 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 327 | MPLS Interface Context Label | 328 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 329 | MPLS GAL | 330 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 331 | MPLS G-ACh | 332 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 333 | | 334 ~ BFD Control Message ~ 335 | | 336 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 337 | FCS | 338 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 340 Figure 4: Geneve Encapsulation of BFD Control Message With the Inner 341 MPLS GAL/G-ACh 343 The BFD packet MUST be carried inside the inner MPLS packet of the 344 Geneve packet. The inner MPLS packet carrying the BFD payload has 345 the following format: 347 MPLS Interface Context Label: This Label would be used to identify 348 the VM-facing interface of the originating NVE and the VM-facing 349 interface of the terminating NVE. 351 MPLS GAL(Generic Associated Channel Label): 353 Label value: MUST be set to 13, as specified in [RFC5586]. 355 S bit: MUST be set to 1. 357 TTL: MUST be set to 1. 359 The fields of the MPLS G-ACh(Generic Associated Channel) and the 360 BFD control packet are encoded as specified for MPLS-TP 361 CC(Continuity Check) message in [RFC6428]. 363 When the BFD packets are encapsulated in Geneve in this way, the 364 Geneve header follows the value set below. 366 Opt Len field SHOULD be set to 0, which indicates there isn't any 367 variable length option. 369 [Ed.Note]: Use of O bit is still being discussed in the NVO3 WG, so 370 the value is undetermined. 372 C bit MUST be set to 0. 374 Protocol Type field MUST be set to 0x8847 (MPLS). 376 3.4. BFD Encapsulation With Inner OAM Shim 378 Also, if the BFD control packet is encapsulated in Geneve without the 379 use of IP/UDP header or MPLS G-ACh header, the BFD control packet MAY 380 be identified through the Geneve OAM shim. The layout of the 381 Ethernet frame is shown in Figure 5. Protocol Type field MUST be set 382 to the value which indicates a Geneve OAM shim that will have a field 383 to indicate the inner BFD control packet. The value of the Protocol 384 Type field and the format of the Geneve OAM shim are defined in 385 [I-D.mmbb-nvo3-geneve-oam]. The Geneve OAM shim immediately follows 386 the Geneve header, and the BFD control packet immediately follows the 387 Geneve OAM shim. 389 0 1 2 3 390 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 1 391 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 392 | | 393 ~ Outer Ethernet Header ~ 394 | | 395 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 396 | | 397 ~ Outer IPvX Header ~ 398 | | 399 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 400 | | 401 ~ Outer UDP Header ~ 402 | | 403 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 404 | | 405 ~ Geneve Header ~ 406 | | 407 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 408 | Geneve OAM Shim | 409 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 410 | | 411 ~ BFD Control Message ~ 412 | | 413 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 414 | FCS | 415 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 417 Figure 5: Geneve Encapsulation of BFD Control Message With Geneve OAM 418 Shim 420 4. Reception of BFD packet from Geneve Tunnel 422 Once a packet is received, NVE MUST validate the packet as described 423 in [I-D.ietf-nvo3-geneve]. 425 If the Protocol Type field equals 0x0800 (IPv4) or 0x86DD (IPv6), and 426 the Destination IP of the inner IP packet matches the VM-facing 427 interface IP address of the NVE, the UDP destination port and the TTL 428 of the inner IP packet MUST be validated to determine whether the 429 received packet can be processed by BFD. BFD packet with inner IP 430 set to NVE MUST NOT be forwarded to VMs. 432 If the Protocol Type field equals 0x8847 (MPLS), the MPLS Interface 433 Context Label, the MPLS GAL and the MPLS G-ACh of the inner MPLS 434 packet MUST be validated to determine whether the received packet can 435 be processed by BFD. BFD packet with MPLS GAL MUST NOT be forwarded 436 to VMs. 438 If the Protocol Type field equals 0x8902 which indicates a Geneve OAM 439 shim that will have a field to indicate the inner BFD control 440 message, as specified in [I-D.mmbb-nvo3-geneve-oam], the received 441 packet MUST be processed by BFD and MUST NOT be forwarded to VMs. 443 4.1. Demultiplexing of the BFD packet 445 Since multiple BFD sessions may be running between two NVEs, and 446 multiple BFD sessions may be originating or terminating at one NVE, 447 there needs to be a mechanism for demultiplexing received BFD packets 448 to the proper session. 450 If the BFD packet is received with Your Discriminator equals to 0, 451 for different BFD encapsulation, the procedure for demultiplexing the 452 received BFD packets is different. 454 When the BFD Encapsulation With Inner Ethernet/IP/UDP Header is 455 used, the BFD session MUST be identified using the procedure 456 specified in Section 5.1 of [I-D.ietf-bfd-vxlan]. 458 When the BFD Encapsulation With Inner IP/UDP Header is used, the 459 BFD session MUST be identified using the inner IP/UDP header, 460 i.e., the source IP and the destination IP present in the inner 461 IP/UDP header. 463 When the BFD Encapsulation With Inner MPLS Header is used, the BFD 464 session MUST be identified using the inner MPLS header, i.e., the 465 MPLS Interface Context Label present in the inner MPLS header. 467 When the BFD Encapsulation With Inner OAM Shim is used, the 468 procedure for demultiplexing the received BFD packets to the 469 proper session is for further study. 471 If the BFD packet is received with non-zero Your Discriminator, then 472 BFD session MUST be demultiplexed only with Your Discriminator as the 473 key. 475 With respect to BFD for Geneve, the use of the specific VNI would 476 follow the principle as specified in Section 6 of 477 [I-D.ietf-bfd-vxlan]. 479 5. Security Considerations 481 This document does not raise any additional security issues beyond 482 those of the specifications referred to in the list of normative 483 references. 485 6. IANA Considerations 487 This document has no IANA action requested. 489 7. Acknowledgements 491 The authors would like to acknowledge Reshad Rahman, Jeffrey Haas and 492 Matthew Bocci for their guidance on this work. 494 8. Normative References 496 [I-D.ietf-bfd-vxlan] 497 Networks, J., Paragiri, S., Govindan, V., Mudigonda, M., 498 and G. Mirsky, "BFD for VXLAN", draft-ietf-bfd-vxlan-07 499 (work in progress), May 2019. 501 [I-D.ietf-nvo3-geneve] 502 Gross, J., Ganga, I., and T. Sridhar, "Geneve: Generic 503 Network Virtualization Encapsulation", draft-ietf- 504 nvo3-geneve-13 (work in progress), March 2019. 506 [I-D.mmbb-nvo3-geneve-oam] 507 Mirsky, G., Xiao, M., Boutros, S., and D. Black, "OAM for 508 use in GENEVE", draft-mmbb-nvo3-geneve-oam-00 (work in 509 progress), July 2019. 511 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 512 Requirement Levels", BCP 14, RFC 2119, 513 DOI 10.17487/RFC2119, March 1997, 514 . 516 [RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed., 517 "MPLS Generic Associated Channel", RFC 5586, 518 DOI 10.17487/RFC5586, June 2009, 519 . 521 [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 522 (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, 523 . 525 [RFC5881] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 526 (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881, 527 DOI 10.17487/RFC5881, June 2010, 528 . 530 [RFC6428] Allan, D., Ed., Swallow, G., Ed., and J. Drake, Ed., 531 "Proactive Connectivity Verification, Continuity Check, 532 and Remote Defect Indication for the MPLS Transport 533 Profile", RFC 6428, DOI 10.17487/RFC6428, November 2011, 534 . 536 [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, 537 L., Sridhar, T., Bursell, M., and C. Wright, "Virtual 538 eXtensible Local Area Network (VXLAN): A Framework for 539 Overlaying Virtualized Layer 2 Networks over Layer 3 540 Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014, 541 . 543 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 544 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 545 May 2017, . 547 Authors' Addresses 549 Xiao Min 550 ZTE 551 Nanjing 552 China 554 Phone: +86 25 88016574 555 Email: xiao.min2@zte.com.cn 557 Greg Mirsky 558 ZTE 559 USA 561 Email: gregimirsky@gmail.com