idnits 2.17.1 draft-ietf-bess-evpn-oam-req-frmwk-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (February 25, 2019) is 1858 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- No issues found here. Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 INTERNET-DRAFT Samer Salam 2 Intended Status: Informational Ali Sajassi 3 Cisco 4 Sam Aldrin 5 Google 6 John E. Drake 7 Juniper 8 Donald Eastlake 9 Huawei 10 Expires: August 24, 2019 February 25, 2019 12 EVPN Operations, Administration and Maintenance 13 Requirements and Framework 14 draft-ietf-bess-evpn-oam-req-frmwk-00 16 Abstract 18 This document specifies the requirements and reference framework for 19 Ethernet VPN (EVPN) Operations, Administration and Maintenance (OAM). 20 The requirements cover the OAM aspects of EVPN and PBB-EVPN. The 21 framework defines the layered OAM model encompassing the EVPN service 22 layer, network layer and underlying Packet Switched Network (PSN) 23 transport layer. 25 Status of this Memo 27 This Internet-Draft is submitted to IETF in full conformance with the 28 provisions of BCP 78 and BCP 79. 30 Internet-Drafts are working documents of the Internet Engineering 31 Task Force (IETF), its areas, and its working groups. Note that 32 other groups may also distribute working documents as Internet- 33 Drafts. 35 Internet-Drafts are draft documents valid for a maximum of six months 36 and may be updated, replaced, or obsoleted by other documents at any 37 time. It is inappropriate to use Internet-Drafts as reference 38 material or to cite them other than as "work in progress." 40 The list of current Internet-Drafts can be accessed at 41 http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft 42 Shadow Directories can be accessed at http://www.ietf.org/shadow.html 44 Copyright and License Notice 46 Copyright (c) 2018 IETF Trust and the persons identified as the 47 document authors. All rights reserved. 49 This document is subject to BCP 78 and the IETF Trust's Legal 50 Provisions Relating to IETF Documents 51 (http://trustee.ietf.org/license-info) in effect on the date of 52 publication of this document. Please review these documents 53 carefully, as they describe your rights and restrictions with respect 54 to this document. Code Components extracted from this document must 55 include Simplified BSD License text as described in Section 4.e of 56 the Trust Legal Provisions and are provided without warranty as 57 described in the Simplified BSD License. 59 Table of Contents 61 1. Introduction............................................4 62 1.1 Relationship to Other OAM Work.........................4 63 1.2 Specification of Requirements..........................5 64 1.3 Terminology............................................5 66 2. EVPN OAM Framework......................................6 67 2.1 OAM Layering...........................................6 68 2.2 EVPN Service OAM.......................................7 69 2.3 EVPN Network OAM.......................................7 70 2.4 Transport OAM for EVPN.................................9 71 2.5 Link OAM...............................................9 72 2.6 OAM Inter-working......................................9 74 3. EVPN OAM Requirements..................................11 75 3.1 Fault Management Requirements.........................11 76 3.1.1 Proactive Fault Management Functions................11 77 3.1.1.1 Fault Detection (Continuity Check)................11 78 3.1.1.2 Defect Indication.................................12 79 3.1.1.2.1 Forward Defect Indication.......................12 80 3.1.1.2.2 Reverse Defect Indication (RDI).................12 81 3.1.2 On-Demand Fault Management Functions................13 82 3.1.2.1 Connectivity Verification.........................13 83 3.1.2.2 Fault Isolation...................................14 84 3.2 Performance Management................................14 85 3.2.1 Packet Loss.........................................14 86 3.2.2 Packet Delay........................................15 88 4. Security Considerations................................16 89 5. Acknowledgements.......................................16 90 6. IANA Considerations....................................16 92 Normative References......................................17 93 Informative References....................................18 95 1. Introduction 97 This document specifies the requirements and defines a reference 98 framework for Ethernet VPN (EVPN) Operations, Administration and 99 Maintenance (OAM, [RFC6291]). In this context, we use the term EVPN 100 OAM to loosely refer to the OAM functions required for and/or 101 applicable to [RFC7432] and [RFC7623]. 103 EVPN is an Layer 2 VPN (L2VPN) solution for multipoint Ethernet 104 services, with advanced multi-homing capabilities, using BGP for 105 distributing customer/client MAC address reachability information 106 over the core MPLS/IP network. 108 PBB-EVPN combines Provider Backbone Bridging (PBB) [802.1Q] with EVPN 109 in order to reduce the number of BGP MAC advertisement routes, 110 provide client MAC address mobility using C-MAC aggregation and B-MAC 111 sub-netting, confine the scope of C-MAC learning to only active 112 flows, offer per site policies, and avoid C-MAC address flushing on 113 topology changes. 115 This document focuses on the fault management and performance 116 management aspects of EVPN OAM. 118 1.1 Relationship to Other OAM Work 120 This document leverages concepts and draws upon elements defined 121 and/or used in the following documents: 123 [RFC6136] specifies the requirements and a reference model for OAM as 124 it relates to L2VPN services, pseudowires and associated Packet 125 Switched Network (PSN) tunnels. This document focuses on VPLS and 126 VPWS solutions and services. 128 [RFC8029] defines mechanisms for detecting data plane failures in 129 MPLS LSPs, including procedures to check the correct operation of the 130 data plane, as well as mechanisms to verify the data plane against 131 the control plane. 133 [802.1Q] specifies the Ethernet Connectivity Fault Management (CFM) 134 protocol, which defines the concepts of Maintenance Domains, 135 Maintenance Associations, Maintenance End Points, and Maintenance 136 Intermediate Points. 138 [Y.1731] extends Connectivity Fault Management in the following 139 areas: it defines fault notification and alarm suppression functions 140 for Ethernet. It also specifies mechanisms for Ethernet performance 141 management, including loss, delay, jitter, and throughput 142 measurement. 144 1.2 Specification of Requirements 146 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 147 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 148 document are to be interpreted as described in [RFC2119] [RFC8174] 149 when, and only when, they appear in all capitals, as shown here. 151 1.3 Terminology 153 This document uses the following terminology defined in [RFC6136]: 155 MA Maintenance Association is a set of MEPs belonging to the same 156 Maintenance Domain, established to verify the integrity of a 157 single service instance. 159 MEP Maintenance End Point is responsible for origination and 160 termination of OAM frames for a given MA. 162 MIP Maintenance Intermediate Point is located between peer MEPs and 163 can process and respond to certain OAM frames but does not 164 initiate them. 166 MD Maintenance Domain, an OAM Domain that represents a region over 167 which OAM frames can operate unobstructed. 169 2. EVPN OAM Framework 171 2.1 OAM Layering 173 Multiple layers come into play for implementing an L2VPN service 174 using the EVPN family of solutions: 176 - The Service Layer runs end to end between the sites or Ethernet 177 Segments that are being interconnected by the EVPN solution. 179 - The Network Layer extends in between the EVPN PE nodes and is 180 mostly transparent to the core nodes (except where Flow Entropy 181 comes into play). It leverages MPLS for service (i.e. EVI) 182 multiplexing and Split-Horizon functions. 184 - The Transport Layer is dictated by the networking technology of the 185 PSN. It may be either based on MPLS LSPs or IP. 187 - The Link Layer is dependent upon the physical technology used. 188 Ethernet is a popular choice for this layer, but other alternatives 189 are deployed (e.g. POS, DWDM etc.). 191 This layering extends to the set of OAM protocols that are involved 192 in the ongoing maintenance and diagnostics of EVPN networks. The 193 figure below depicts the OAM layering, and shows which devices have 194 visibility into what OAM layer(s). 196 +---+ +---+ 197 +--+ | | +---+ +---+ +---+ | | +--+ 198 |CE|----|PE1|----| P |----| P |----| P |----|PE2|----|CE| 199 +--+ | | +---+ +---+ +---+ | | +--+ 200 +---+ +---+ 202 o--------o--------- Service OAM -------------o--------o 204 o----------- Network OAM -----------o 206 o--------o--------o---------o-------o Transport OAM 208 o-----o o-----o o-----o o-----o o-----o o-----o Link OAM 210 Figure 1: OAM Layering 212 Figure 2 below shows an example network where native Ethernet domains 213 are interconnected via EVPN, and the OAM mechanisms applicable at 214 each layer. The details of the layers are described in the sections 215 below. 217 +---+ +---+ 218 +--+ | | +---+ +---+ +---+ | | +--+ 219 |CE|----|PE1|----| P |----| P |----| P |----|PE2|----|CE| 220 +--+ | | +---+ +---+ +---+ | | +--+ 221 +---+ +---+ 223 o--------o--------- Service CFM -------------o--------o 225 o-------- EVPN Network OAM ---------o 227 o--------o--------o---------o-------o MPLS OAM 229 o-----o o-----o o-----o o-----o o-----o o-----o 802.3 OAM 231 Figure 2: EVPN OAM Example 233 2.2 EVPN Service OAM 235 The EVPN Service OAM protocol depends on what service layer 236 technology is being interconnected by the EVPN solution. In case of 237 [RFC7432] and [RFC7623], the service layer is Ethernet; hence, the 238 corresponding service OAM protocol is Ethernet Connectivity Fault 239 Management (CFM) [802.1Q]. 241 EVPN service OAM is visible to the CEs and EVPN PEs, but not to the 242 core (P) nodes. This is because the PEs operate at the Ethernet MAC 243 layer in [RFC7432] [RFC7623] whereas the P nodes do not. 245 The EVPN PE MUST support MIP functions in the applicable service OAM 246 protocol, for example Ethernet CFM. The EVPN PE SHOULD support MEP 247 functions in the applicable service OAM protocol. This includes both 248 Up and Down MEP functions. 250 The EVPN PE MUST learn the MAC address of locally attached CE MEPs by 251 snooping on CFM frames and advertising them to remote PEs as a MAC/IP 252 Advertisement route. 254 The EVPN PE SHOULD advertise any MEP/MIP local to the PE as a MAC/IP 255 Advertisement route. Since these are not subject to mobility, they 256 SHOULD be advertised with the stick bit set (see Section 15.2 of 257 [RFC7432]). 259 2.3 EVPN Network OAM 261 EVPN Network OAM is visible to the PE nodes only. This OAM layer is 262 analogous to VCCV [RFC5085] in the case of VPLS/VPWS. It provides 263 mechanisms to check the correct operation of the data plane, as well 264 as a mechanism to verify the data plane against the control plane. 265 This includes the ability to perform fault detection and diagnostics 266 on: 268 - the MP2P tunnels used for the transport of unicast traffic between 269 PEs. EVPN allows for three different models of unicast label 270 assignment: label per EVI, label per and label 271 per MAC address. In all three models, the label is bound to an EVPN 272 Unicast FEC. 274 EVPN Network OAM MUST provide mechanisms to check the operation of 275 the data plane and verify that operation against the control plane 276 view. 278 - the MP2P tunnels used for aliasing unicast traffic destined to a 279 multi-homed Ethernet Segment. The three label assignment models, 280 discussed above, apply here as well. In all three models, the label 281 is bound to an EVPN Aliasing FEC. EVPN Network OAM MUST provide 282 mechanisms to check the operation of the data plane and verify that 283 operation against the control plane view. 285 - the multicast tunnels (either MP2P or P2MP) used for the transport 286 of broadcast, unknown unicast and multicast traffic between PEs. In 287 the case of ingress replication, a label is allocated per EVI or 288 per and is bound to an EVPN Multicast FEC. In 289 the case of LSM, and more specifically aggregate inclusive trees, 290 again a label may be allocated per EVI or per 291 and is bound to the tunnel FEC. 293 - the correct operation of the ESI split-horizon filtering function. 294 In EVPN, a label is allocated per multi-homed Ethernet Segment for 295 the purpose of performing the access split-horizon enforcement. The 296 label is bound to an EVPN Ethernet Segment. 298 - the correct operation of the DF filtering function. 300 EVPN Network OAM MUST provide mechanisms to check the operation of 301 the data plane and verify that operation against the control plane 302 view for the DF filtering function. 304 EVPN network OAM mechanisms MUST provide in-band management 305 capabilities. As such, OAM messages MUST be encoded so that they 306 exhibit identical entropy characteristics to data traffic. 308 EVPN network OAM SHOULD provide both proactive and on-demand 309 mechanisms of monitoring the data plane operation and data plane 310 conformance to the state of the control plane. 312 2.4 Transport OAM for EVPN 314 The transport OAM protocol depends on the nature of the underlying 315 transport technology in the PSN. MPLS OAM mechanisms [RFC8029] 316 [RFC6425] as well as ICMP [RFC792] are applicable, depending on 317 whether the PSN employs MPLS or IP transport, respectively. 318 Furthermore, BFD mechanisms per [RFC5880], [RFC5881], [RFC5883] and 319 [RFC5884] apply. Also, the BFD mechanisms pertaining to MPLS-TP LSPs 320 per [RFC6428] are applicable. 322 2.5 Link OAM 324 Link OAM depends on the data link technology being used between the 325 PE and P nodes. For example, if Ethernet links are employed, then 326 Ethernet Link OAM [802.3] Clause 57 may be used. 328 2.6 OAM Inter-working 330 When inter-working two networking domains, such as native Ethernet 331 and EVPN to provide an end-to-end emulated service, there is a need 332 to identify the failure domain and location, even when a PE supports 333 both the Service OAM mechanisms and the EVPN Network OAM mechanisms. 334 In addition, scalability constraints may not allow running proactive 335 monitoring, such as Ethernet Continuity Check Messages (CCMs), at a 336 PE to detect the failure of an EVI across the EVPN domain. Thus, the 337 mapping of alarms generated upon failure detection in one domain 338 (e.g. native Ethernet or EVPN network domain) to the other domain is 339 needed. There are also cases where a PE may not be able to process 340 Service OAM messages received from a remote PE over the PSN even when 341 such messages are defined, as in the Ethernet case, thereby 342 necessitating support for fault notification message mapping between 343 the EVPN Network domain and the Service domain. 345 OAM inter-working is not limited though to scenarios involving 346 disparate network domains. It is possible to perform OAM inter- 347 working across different layers in the same network domain. In 348 general, alarms generated within an OAM layer, as a result of 349 proactive fault detection mechanisms, may be injected into its client 350 layer OAM mechanisms. This allows the client layer OAM to trigger 351 event-driven (i.e. asynchronous) fault notifications. For example, 352 alarms generated by the Link OAM mechanisms may be injected into the 353 Transport OAM layer, and alarms generated by the Transport OAM 354 mechanism may be injected into the Network OAM mechanism, and so on. 356 EVPN OAM MUST support inter-working between the Network OAM and 357 Service OAM mechanisms. EVPN OAM MAY support inter-working among 358 other OAM layers. 360 3. EVPN OAM Requirements 362 This section discusses the EVPN OAM requirements pertaining to Fault 363 Management and Performance Management. 365 3.1 Fault Management Requirements 367 3.1.1 Proactive Fault Management Functions 369 The network operator configures proactive fault management functions 370 to run periodically without a time bound. Certain actions, for 371 example protection switchover or alarm indication signaling, can be 372 associated with specific events, such as entering or clearing fault 373 states. 375 3.1.1.1 Fault Detection (Continuity Check) 377 Proactive fault detection is performed by periodically monitoring the 378 reachability between service endpoints, i.e. MEPs in a given MA, 379 through the exchange of Continuity Check messages. The reachability 380 between any two arbitrary MEPs may be monitored for: 382 - in-band per-flow monitoring. This enables per flow monitoring 383 between MEPs. EVPN Network OAM MUST support fault detection with 384 per user flow granularity. EVPN Service OAM MAY support fault 385 detection with per user flow granularity. 387 - a representative path. This enables liveness check of the nodes 388 hosting the MEPs assuming that the loss of continuity to the MEP is 389 interpreted as a failure of the hosting node. This, however, does 390 not conclusively indicate liveness of the path(s) taken by user 391 data traffic. This enables node failure detection but not path 392 failure detection, through the use of a test flow. EVPN Network OAM 393 and Service OAM MUST support fault detection using test flows. 395 - all paths. For MPLS/IP networks with ECMP, monitoring of all 396 unicast paths between MEPs (on non-adjacent nodes) may not be 397 possible, since the per-hop ECMP hashing behavior may yield 398 situations where it is impossible for a MEP to pick flow entropy 399 characteristics that result in exercising the exhaustive set of 400 ECMP paths. Monitoring of all ECMP paths between MEPs (on non- 401 adjacent nodes) is not a requirement for EVPN OAM. 403 The fact that MPLS/IP networks do not enforce congruency between 404 unicast and multicast paths means that the proactive fault detection 405 mechanisms for EVPN networks MUST provide procedures to monitor the 406 unicast paths independently of the multicast paths. This applies to 407 EVPN Service OAM and Network OAM. 409 3.1.1.2 Defect Indication 411 EVPN Service OAM MUST support event-driven defect indication upon the 412 detection of a connectivity defect. Defect indications can be 413 categorized into two types: forward and reverse defect indications. 415 3.1.1.2.1 Forward Defect Indication 417 This is used to signal a failure that is detected by a lower layer 418 OAM mechanism. A server MEP (i.e. an actual or virtual MEP) transmits 419 a Forward Defect Indication in a direction that is away from the 420 direction of the failure (refer to Figure 3 below). 422 Failure 423 | 424 +-----+ +-----+ V +-----+ +-----+ 425 | A |------| B |--XXX--| C |------| D | 426 +-----+ +-----+ +-----+ +-----+ 428 <===========| |============> 429 Forward Forward 430 Defect Defect 431 Indication Indication 433 Figure 3: Forward Defect Indication 435 Forward defect indication may be used for alarm suppression and/or 436 for purpose of inter-working with other layer OAM protocols. Alarm 437 suppression is useful when a transport/network level fault translates 438 to multiple service or flow level faults. In such a scenario, it is 439 enough to alert a network management station (NMS) of the single 440 transport/network level fault in lieu of flooding that NMS with a 441 multitude of Service or Flow granularity alarms. EVPN PEs SHOULD 442 support Forward Defect Indication in the Service OAM mechanisms. 444 3.1.1.2.2 Reverse Defect Indication (RDI) 446 RDI is used to signal that the advertising MEP has detected a loss of 447 continuity (LoC) defect. RDI is transmitted in the direction of the 448 failure (refer to Figure 4). 450 Failure 451 | 452 +-----+ +-----+ V +-----+ +-----+ 453 | A |------| B |--XXX--| C |------| D | 454 +-----+ +-----+ +-----+ +-----+ 456 |===========> <============| 457 Reverse Reverse 458 Defect Defect 459 Indication Indication 461 Figure 4: Reverse Defect Indication 463 RDI allows single-sided management, where the network operator can 464 examine the state of a single MEP and deduce the overall health of a 465 monitored service. EVPN PEs SHOULD support Reverse Defect Indication 466 in the Service OAM mechanisms. This includes both the ability to 467 signal LoC defect to a remote MEP, as well as the ability to 468 recognize RDI from a remote MEP. Note that, in a multipoint MA, RDI 469 is not a useful indicator of unidirectional fault. This is because 470 RDI carries no indication of the affected MEP(s) with which the 471 sender had detected a LoC defect. 473 3.1.2 On-Demand Fault Management Functions 475 On-demand fault management functions are initiated manually by the 476 network operator and continue for a time bound period. These 477 functions enable the operator to run diagnostics to investigate a 478 defect condition. 480 3.1.2.1 Connectivity Verification 482 EVPN Network OAM MUST support on-demand connectivity verification 483 mechanisms for unicast and multicast destinations. The connectivity 484 verification mechanisms SHOULD provide a means for specifying and 485 carrying in the messages: 487 - variable length payload/padding to test MTU related connectivity 488 problems. 490 - test frame formats as defined in Appendix C of [RFC2544] to detect 491 potential packet corruption. 493 EVPN Network OAM MUST support connectivity verification at per flow 494 granularity. This includes both user flows (to test a specific path 495 between PEs) as well as test flows (to rest a representative path 496 between PEs). 498 EVPN Service OAM MUST support connectivity verification on test flows 499 and MAY support connectivity verification on user flows. 501 For multicast connectivity verification, EVPN Network OAM MUST 502 support reporting on: 504 - the DF filtering status of specific port(s) or all the ports in a 505 given bridge-domain. 507 - the Split Horizon filtering status of specific port(s) or all the 508 ports in a given bridge-domain. 510 3.1.2.2 Fault Isolation 512 EVPN OAM MUST support an on-demand fault localization function. This 513 involves the capability to narrow down the locality of a fault to a 514 particular port, link or node. The characteristic of forward/reverse 515 path asymmetry, in MPLS/IP, renders fault isolation into a direction- 516 sensitive operation. That is, given two PEs A and B, localization of 517 continuity failures between them requires running fault isolation 518 procedures from PE A to PE B as well as from PE B to PE A. 520 EVPN Service OAM mechanisms only have visibility to the PEs but not 521 the MPLS/IP P nodes. As such, they can be used to deduce whether the 522 fault is in the customer's own network, the local CE-PE segment or 523 remote CE-PE segment(s). EVPN Network and Transport OAM mechanisms 524 can be used for fault isolation between the PEs and P nodes. 526 3.2 Performance Management 528 Performance Management functions can be performed both proactively 529 and on-demand. Proactive management involves a recurring function, 530 where the performance management probes are run continuously without 531 a trigger. We cover both proactive and on-demand functions in this 532 section. 534 3.2.1 Packet Loss 536 EVPN Network OAM SHOULD provide mechanisms for measuring packet loss 537 for a given service. 539 Given that EVPN provides inherent support for multipoint-to- 540 multipoint connectivity, then packet loss cannot be accurately 541 measured by means of counting user data packets. This is because user 542 packets can be delivered to more PEs or more ports than are necessary 543 (e.g. due to broadcast, un-pruned multicast or unknown unicast 544 flooding). As such, a statistical means of approximating packet loss 545 rate is required. This can be achieved by sending "synthetic" OAM 546 packets that are counted only by those ports (MEPs) that are required 547 to receive them. This provides a statistical approximation of the 548 number of data frames lost, even with multipoint-to-multipoint 549 connectivity. 551 3.2.2 Packet Delay 553 EVPN Service OAM SHOULD support measurement of one-way and two-way 554 packet delay and delay variation (jitter) across the EVPN network. 555 Measurement of one-way delay requires clock synchronization between 556 the probe source and target devices. Mechanisms for clock 557 synchronization are outside the scope of this document. Note that 558 Service OAM performance management mechanisms defined in [Y.1731] can 559 be used. 561 EVPN Network OAM MAY support measurement of one-way and two-way 562 packet delay and delay variation (jitter) across the EVPN network. 564 4. Security Considerations 566 EVPN OAM must provide mechanisms for: 568 - Preventing denial of service attacks caused by exploitation of the 569 OAM message channel. 571 - Optionally authenticate communicating endpoints (MEPs and MIPs) 573 - Preventing OAM packets from leaking outside of the EVPN network or 574 outside their corresponding Maintenance Domain. This can be done by 575 having MEPs implement a filtering function based on the Maintenance 576 Level associated with received OAM packets. 578 5. Acknowledgements 580 The authors would like to thank the following for their review of 581 this work and valuable comments: 583 Gregory Mirsky, Alexander Vainshtein 585 6. IANA Considerations 587 This document requires no IANA actions. 589 Normative References 591 [RFC792] Postel, J., "Internet Control Message Protocol", STD 5, RFC 592 792, DOI 10.17487/RFC0792, September 1981, 593 . 595 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 596 Requirement Levels", BCP 14, RFC 2119, DOI 597 10.17487/RFC2119, March 1997, . 600 [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 601 (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, 602 . 604 [RFC5881] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 605 (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881, DOI 606 10.17487/RFC5881, June 2010, . 609 [RFC5883] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 610 (BFD) for Multihop Paths", RFC 5883, DOI 10.17487/RFC5883, 611 June 2010, . 613 [RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, 614 "Bidirectional Forwarding Detection (BFD) for MPLS Label 615 Switched Paths (LSPs)", RFC 5884, DOI 10.17487/RFC5884, 616 June 2010, .< 618 [RFC6291] Andersson, L., van Helvoort, H., Bonica, R., Romascanu, D., 619 and S. Mansfield, "Guidelines for the Use of the "OAM" 620 Acronym in the IETF", BCP 161, RFC 6291, DOI 621 10.17487/RFC6291, June 2011, . 624 [RFC6425] Saxena, S., Ed., Swallow, G., Ali, Z., Farrel, A., 625 Yasukawa, S., and T. Nadeau, "Detecting Data-Plane Failures 626 in Point-to-Multipoint MPLS - Extensions to LSP Ping", RFC 627 6425, DOI 10.17487/RFC6425, November 2011, 628 . 630 [RFC6428] Allan, D., Ed., Swallow, G., Ed., and J. Drake, Ed., 631 "Proactive Connectivity Verification, Continuity Check, and 632 Remote Defect Indication for the MPLS Transport Profile", 633 RFC 6428, DOI 10.17487/RFC6428, November 2011, 634 . 636 [RFC7432] Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A., 637 Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based 638 Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February 639 2015, . 641 [RFC7623] Sajassi, A., Ed., Salam, S., Bitar, N., Isaac, A., and W. 642 Henderickx, "Provider Backbone Bridging Combined with 643 Ethernet VPN (PBB-EVPN)", RFC 7623, DOI 10.17487/RFC7623, 644 September 2015, . 646 [RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N., 647 Aldrin, S., and M. Chen, "Detecting Multiprotocol Label 648 Switched (MPLS) Data-Plane Failures", RFC 8029, DOI 649 10.17487/RFC8029, March 2017, . 652 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 653 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 654 2017, 656 Informative References 658 [802.1Q] "IEEE Standard for Local and metropolitan area networks - 659 Media Access Control (MAC) Bridges and Virtual Bridge Local 660 Area Networks", 2014. 662 [Y.1731] "ITU-T Recommendation Y.1731 (02/08) - OAM functions and 663 mechanisms for Ethernet based networks", February 2008. 665 [RFC2544] Bradner, S. and J. McQuaid, "Benchmarking Methodology for 666 Network Interconnect Devices", RFC 2544, DOI 667 10.17487/RFC2544, March 1999, . 670 [RFC5085] Nadeau, T., Ed., and C. Pignataro, Ed., "Pseudowire Virtual 671 Circuit Connectivity Verification (VCCV): A Control Channel 672 for Pseudowires", RFC 5085, DOI 10.17487/RFC5085, December 673 2007, . 675 [RFC6136] Sajassi, A., Ed., and D. Mohan, Ed., "Layer 2 Virtual 676 Private Network (L2VPN) Operations, Administration, and 677 Maintenance (OAM) Requirements and Framework", RFC 6136, 678 DOI 10.17487/RFC6136, March 2011, . 681 Authors' Addresses 683 Samer Salam 684 Cisco 686 Email: ssalam@cisco.com 688 Ali Sajassi 689 Cisco 690 170 West Tasman Drive 691 San Jose, CA 95134, USA 693 Email: sajassi@cisco.com 695 Sam Aldrin 696 Google, Inc. 697 1600 Amphitheatre Parkway 698 Mountain View, CA USA 700 Email: aldrin.ietf@gmail.com 702 John E. Drake 703 Juniper Networks 704 1194 N. Mathilda Ave. 705 Sunnyvale, CA 94089, USA 707 Email: jdrake@juniper.net 709 Donald E. Eastlake, 3rd 710 Huawei Technologies 711 1424 Pro Shop Court 712 Davenport, FL 33896 USA 714 Tel: +1-508-333-2270 715 Email: d3e3e3@gmail.com