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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 INTERNET-DRAFT Mohammed Umair 3 Intended Status: Informational Kingston Smiler Selvaraj 4 IPInfusion 5 Donald Eastlake 3rd 6 Lucy Yong 7 Huawei Technologies 8 Expires: October 23, 2017 April 21, 2017 10 TRILL Transparent Transport over MPLS 11 13 Abstract 15 This document specifies how to interconnect multiple Transparent 16 Interconnection of Lots of links (TRILL) sites with an intervening 17 MPLS network using existing TRILL and VPLS standards. This draft 18 addresses two problems as follows: 20 1) Providing connection between more than two TRILL sites that 21 are separated by MPLS an provider network. 23 2) Providing a single logical virtualized TRILL network for 24 different tenants that are separated by an MPLS provider network. 26 Status of this Memo 28 This Internet-Draft is submitted to IETF in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF), its areas, and its working groups. Note that 33 other groups may also distribute working documents as 34 Internet-Drafts. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 The list of current Internet-Drafts can be accessed at 42 http://www.ietf.org/1id-abstracts.html 44 The list of Internet-Draft Shadow Directories can be accessed at 45 http://www.ietf.org/shadow.html 47 Copyright and License Notice 49 Copyright (c) 2017 IETF Trust and the persons identified as the 50 document authors. All rights reserved. 52 This document is subject to BCP 78 and the IETF Trust's Legal 53 Provisions Relating to IETF Documents 54 (http://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 Table of Contents 64 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 65 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4 66 2. TRILL Over MPLS Model . . . . . . . . . . . . . . . . . . . . . 5 67 3. VPLS Model . . . . . . . . . . . . . . . . . . . . . . . . . . 6 68 3.1. Entities in the VPLS Model . . . . . . . . . . . . . . . . 7 69 3.3. TRILL Adjacency for VPLS model . . . . . . . . . . . . . . 8 70 3.4. MPLS encapsulation for VPLS model . . . . . . . . . . . . . 8 71 3.5. Loop Free provider PSN/MPLS. . . . . . . . . . . . . . . . 8 72 3.6. Frame processing. . . . . . . . . . . . . . . . . . . . . . 8 73 4. VPTS Model . . . . . . . . . . . . . . . . . . . . . . . . . . 8 74 4.1. Entities in the VPTS Model . . . . . . . . . . . . . . . . 10 75 4.1.1. TRILL Intermediate Routers (TIR) . . . . . . . . . . . 11 76 4.1.2. Virtual TRILL Switch/Service Domain (VTSD) . . . . . . 11 77 4.2. TRILL Adjacency for VPTS model . . . . . . . . . . . . . . 11 78 4.3. MPLS encapsulation for VPTS model . . . . . . . . . . . . . 12 79 4.4. Loop Free provider PSN/MPLS. . . . . . . . . . . . . . . . 12 80 4.5. Frame processing. . . . . . . . . . . . . . . . . . . . . . 12 81 4.5.1. Multi-Destination Frame processing . . . . . . . . . . 12 82 4.5.2. Unicast Frame processing . . . . . . . . . . . . . . . 12 83 5. Extensions to TRILL Over Pseudowires [RFC7173] . . . . . . . . 12 84 6. VPTS Model Versus VPLS Model . . . . . . . . . . . . . . . . . 13 85 7. Packet processing between pseudowires . . . . . . . . . . . . . 13 86 8. Security Considerations . . . . . . . . . . . . . . . . . . . . 14 87 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 14 88 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14 89 10.1. Normative References . . . . . . . . . . . . . . . . . . . 14 90 10.2. Informative References . . . . . . . . . . . . . . . . . . 15 91 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . 15 92 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16 94 1. Introduction 96 The IETF Transparent Interconnection of Lots of Links (TRILL) 97 protocol [RFC6325] [RFC7177] [RFC7780] provides transparent 98 forwarding in multi-hop networks with arbitrary topology and link 99 technologies using a header with a hop count and link-state routing. 100 TRILL provides optimal pair-wise forwarding without configuration, 101 safe forwarding even during periods of temporary loops, and support 102 for multipathing of both unicast and multicast traffic. Intermediate 103 Systems (ISs) implementing TRILL are called Routing Bridges(RBridges) 104 or TRILL Switches 106 This draft, in conjunction with [RFC7173] on TRILL Transport using 107 Pseudowires, addresses two problems: 109 1) Providing connection between more than two TRILL sites belongs to 110 a single TRILL network that are separated by an MPLS provider network 111 using [RFC7173]. (Herein also called problem statement 1.) 113 2) Providing a single logical virtualized TRILL network for different 114 tenants that are separated by an MPLS provider network. In short 115 providing connection between TRILL sites belonging to a 116 tenant/tenants over a MPLS provider network. (Herein also called 117 problem statement 2.) 119 A tenant is the administrative entity on whose behalf their 120 associated services are managed. Here tenant refers to a TRILL campus 121 that is segregated from other tenants for security reasons. 123 A key multi-tenancy requirement is traffic isolation so that one 124 tenant's traffic is not visible to any other tenant. This draft also 125 addresses the problem of multi-tenancy by isolating one tenant's 126 traffic from the other. 128 1.1. Terminology 130 Acronyms used in this document include the following: 132 AC - Attachment Circuit [RFC4664] 134 Data Label - VLAN or FGL 136 ECMP - Equal Cost Multi Path 138 FGL - Fine-Grained Labeling [RFC7172] 140 IS-IS - Intermediate System to Intermediate 141 System [IS-IS] 143 LDP - Label Distribution Protocol 145 LAN - Local Area Network 147 MPLS - Multi-Protocol Label Switching 149 PE - Provider Edge Device 151 PSN - Packet Switched Network 153 PW - Pseudowire [RFC4664] 155 TIR - TRILL Intermediate Router 156 (Devices that has both IP/MPLS and TRILL 157 functionality) 159 TRILL - Transparent Interconnection of Lots of 160 Links OR Tunneled Routing in the Link Layer 162 TRILL Site - A part of a TRILL campus that contains at 163 least one RBridge. 165 VLAN - Virtual Local Area Network 167 VPLS - Virtual Private LAN Service 169 VPTS - Virtual Private TRILL Service 171 VSI - Virtual Service Instance [RFC4664] 173 VTSD - Virtual TRILL Switch Domain 174 OR Virtual TRILL Service Domain 175 A Virtual RBridge that segregates one 176 tenant's TRILL database as well as 177 traffic from the other. 179 WAN - Wide Area Network 181 2. TRILL Over MPLS Model 183 TRILL Over MPLS can be achieved by two different ways. 185 a) VPLS Model for TRILL 186 b) VPTS Model/TIR Model 188 Both these models can be used to solve the problem statement 1 and 2. 189 Herein the VPLS Model for TRILL is also called Model 1 and the VPTS 190 Model/TIR Model is also called Model 2. 192 3. VPLS Model 194 Figure 1 shows the topological model of TRILL over MPLS using VPLS 195 model. The PE routers in the below topology model should support all 196 the functional Components mentioned in [RFC4664]. 198 +-----+ +-----+ 199 | RBa +---+ ........................... +---| RBb | 200 +-----+ | . . | +-----+ 201 Site 1 | +----+ +----+ | Site 2 202 +----|PE1 | |PE2 |----+ 203 +----+ MPLS Cloud +----+ 204 . . 205 . +----+ . 206 ..........|PE3 |........... 207 +----+ ^ 208 | | 209 | +-- Emulated LAN 210 +-----+ 211 | RBc | 212 +-----+ 213 Site 3 215 Figure 1: Topological Model of TRILL over MPLS 216 connecting three TRILL Sites 218 Figure 2 below shows the topological model of TRILL over MPLS to 219 connect multiple TRILL sites belonging to a tenant (tenant here is a 220 campus, not a Data label). VSI1 and VSI2 are two Virtual Service 221 Instances that segregate Tenant1's traffic from other tenant traffic. 222 VSI1 will maintain its own database for Tenant1, similarly VSI2 will 223 maintain its own database for Tenant2. 225 +-----+ ............................ +-----+ 226 |RBat1+---+ . ++++++++++++++++++++++++ . +---|RBbt1| 227 +-----+ | . + + . | +-----+ 228 Tenant1 Site 1 | +----+ +----+ | Tenant1 Site2 229 +----|VSI1| |VSI1|----+ 230 +----|VSI2| MPLS Cloud |VSI2|----+ 231 | +----+ +----+ | 232 +-----+ | . + + . | +-----+ 233 |RBat2+---+ . +++++++++ +----+ ++++++++ . +---|RBbt2| 234 +-----+ ............|VSI1|........... +-----+ 235 Tenant2 Site 2 +----|VSI2|----+ ^ Tenant2 Site2 236 | +----+ | | 237 | | | 238 +-----+ +-----+ +-----Emulated 239 |RBct2| |RBct1| LAN 240 +-----+ +-----+ 241 Tenant2 Site 3 Tenant1 Site 3 243 .... VSI1 Path 244 ++++ VSI2 Path 246 Figure 2: Topological Model for VPLS Model 247 connecting 2 Tenants with 3 sites each 249 In this model, TRILL sites are connected to VPLS-capable PE devices that 250 provide a logical interconnect, such that TRILL RBridges belonging to a 251 specific tenant connected via an single bridged Ethernet. These devices 252 are the same as PE devices specified in [RFC4026]. The Attachment 253 Circuit ports of PE Routers are layer 2 switch ports that are connected 254 to the RBridges at a TRILL site. Here each VPLS instance looks like an 255 emulated LAN. This model is similar to connecting different RBridges 256 (TRILL sites) by a layer 2 bridge domain (multi access link) as 257 specified in [RFC6325]. This model doesn't requires any changes in PE 258 routers to carry TRILL packets, as TRILL packets will be transferred 259 transparently. 261 3.1. Entities in the VPLS Model 263 The PE (VPLS-PE) and CE devices are defined in [RFC4026]. 265 The Generic L2VPN Transport Functional Components like Attachment 266 Circuits, Pseudowires, VSI etc. are defined in [RFC4664]. 268 The RB (RBridge) and TRILL Sites are defined in [RFC6325] as updated by 269 [RFC7780]. 271 3.3. TRILL Adjacency for VPLS model 273 As specified in section 3 of this document, the MPLS cloud looks like an 274 emulated LAN (also called multi-access link or broadcast link). This 275 results in RBridges at different sites looking like they are connected 276 by a multi-access link. With such interconnection, the TRILL adjacency 277 over the link are automatically discovered and established through TRILL 278 IS-IS control messages [RFC7177]. These IS-IS control messages are 279 transparently forwarded by the VPLS domain, after doing MPLS 280 encapsulation specified in the section 3.4. 282 3.4. MPLS encapsulation for VPLS model 284 Use of VPLS [RFC4762] [RFC4761] to interconnect TRILL sites requires no 285 changes to a VPLS implementation, in particular the use of Ethernet 286 pseudowires between VPLS PEs. A VPLS PE receives normal Ethernet frames 287 from an RBridge (i.e., CE) and is not aware that the CE is an RBridge 288 device. As an example, an MPLS-encapsulated TRILL packet within the MPLS 289 network will use the format illustrated in Appendix A of [RFC7173] for 290 non-PBB case. For the PBB case, which is outside the scope of this 291 document, additional header fields illustrated in [RFC7041] can be used. 293 3.5. Loop Free provider PSN/MPLS. 295 No explicit handling is required to avoid loop free topology. Split 296 Horizon technique specified in [RFC4664] will take care of avoiding 297 loops in the provider PSN network. 299 3.6. Frame processing. 301 The PE device transparently process the TRILL control and data frames. 302 Procedures to forward the frames are defined in [RFC4664] 304 4. VPTS Model 306 The (Virtual Private TRILL Service) VPTS is a L2 TRILL service, that 307 emulates TRILL service across a Wide Area Network (WAN). VPTS is similar 308 to what VPLS does for bridge domain. VPLS provides "Virtual Private LAN 309 Service" for different customers. VPTS provides "Virtual Private TRILL 310 Service" for different TRILL tenants. 312 Figure 3 shows the topological model of TRILL over MPLS using VPTS. In 313 this model the PE routers are replaced with TIR (TRILL Intermediate 314 Router) and VSI is replaced with VTSD (Virtual TRILL Switch Domain). The 315 TIR devices must be capable of supporting both MPLS and TRILL and is 316 defined in section 4.1.1. The TIR devices are interconnected via PWs and 317 appear as a unified emulated TRILL campus with each VTSD inside a TIR 318 equivalent to a RBridge. 320 Some of the reasons for interconnecting TRILL Sites without isolating 321 TRILL Control plane of one TRILL site with other is as described below. 323 1) Nickname Uniqueness: One of the basic requirements of TRILL is that, 324 RBridge Nicknames should be unique with in the campus. If we segregate 325 control plane of one TRILL site from other TRILL site and provide 326 interconnection between these sites, it may result in Nickname 327 collision. 329 2) Distribution Tree and its pruning: When a TRILL Data packet traverse 330 a Distribution Tree, it will adhere to it even in other TRILL site. If 331 no end-station service is enabled for a particular Data Label in a TRILL 332 site, Distribution Tree may be pruned and TRILL data packets of that 333 particular Data Label might never get to other TRILL sites. RPF check 334 will always be performed on the packets that are received TIR's through 335 pseudowires. 337 3) Hop Count values: When a TRILL data packet is received over a 338 pseudowire by a TIR, the TIR does the processing of Hop Count defined in 339 [RFC6325] and will not perform any resetting of Hop Count. 341 +-----+ +-----+ 342 | RBa +---+ ........................... +---| RBb | 343 +-----+ | . . | +-----+ 344 Site 1 | +----+ +----+ | Site 2 345 +----|TIR1| |TIR2|----+ 346 +----+ MPLS Cloud +----+ 347 . . 348 . +----+ . 349 ..........|TIR3|........... 350 +----+ ^ 351 | | 352 | +-- Emulated TRILL 353 +-----+ 354 | RBc | 355 +-----+ 356 Site 3 358 Figure 3: Topological Model of VPTS/TIR 359 connecting three TRILL Sites 361 In the above figure (Figure 3) Site1, Site2 and Site3 (running TRILL 362 protocol) are connected to TIR Devices. These TIR devices along with 363 the MPLS cloud looks like an unified emulated TRILL campus. Only the PE 364 devices in the MPLS network should be replaced with TIRs so the 365 intermediate P routers are agnostic to the TRILL protocol. 367 Figure 4 below extends the topological model of TRILL over MPLS to 368 connect multiple TRILL sites belonging to a tenant (tenant here is a 369 campus, not a Data label) using VPTS model. VTSD1 and VTSD2 are two 370 Virtual TRILL Switch Domains (Virtual RBridges) that segregate 371 Tenant1's traffic from Tenant2's traffic. VTSD1 will maintain its own 372 TRILL database for Tenant1, similarly VTSD2 will maintain its own TRILL 373 database for Tenant2. 375 +-----+ ............................ +-----+ 376 |RBat1+---+ . ######################## . +---|RBbt1| 377 +-----+ | . # # . | +-----+ 378 Tenant1 Site 1| +-----+ +-----+ | Tenant1 Site 2 379 +----|VTSD1| |VTSD1|----+ 380 +----|VTSD2| MPLS Cloud |VTSD2|----+ 381 | +-----+ +-----+ | 382 +-----+ | . # # . | +-----+ 383 |RBat2+---+ . #########+-----+######### . +---|RBbt2| 384 +-----+ ...........|VTSD1|........... +-----+ 385 Tenant2 Site2 +---|VTSD2|----+ ^ Tenant2 Site 2 386 | +-----+ | | 387 | | | 388 +-----+ +-----+ +-----Emulated 389 |RBct2| |RBct1| TRILL 390 +-----+ +-----+ 391 Tenant2 Site 3 Tenant1 Site 3 393 .... VTSD1 Connectivity 394 #### VTSD2 Connectivity 396 Figure 4: Topological Model of VPTS/TIR 397 connecting 2 tenants with three TRILL Sites 399 4.1. Entities in the VPTS Model 400 The CE devices are defined in [RFC4026]. 402 The Generic L2VPN Transport Functional Components like Attachment 403 Circuits, Pseudowires etc. are defined in [RFC4664]. 405 The RB (RBridge) and TRILL Campus are defined in [RFC6325] as updated by 406 [RFC7780]. 408 This model introduces two new entities called TIR and VTSD. 410 4.1.1. TRILL Intermediate Routers (TIR) 412 The TIRs [TRILL Intermediate Routers] must be capable of running both 413 VPLS and TRILL protocols. TIR devices are a superset of the VPLS-PE 414 devices defined in [RFC4026] with the additional functionality of TRILL. 415 The VSI instance that provides transparent bridging functionality in the 416 PE device is replaced with VTSD in TIR. 418 4.1.2. Virtual TRILL Switch/Service Domain (VTSD) 420 The VTSD [Virtual Trill Switch Domain] is similar to VSI (layer 2 421 bridge) in VPLS model, but this acts as a TRILL RBridge. The VTSD is a 422 superset of VSI and must support all the functionality provided by the 423 VSI as defined in [RFC4026]. Along with VSI functionality, the VTSD must 424 be capable of supporting TRILL protocols and form TRILL adjacencies. The 425 VTSD must be capable of performing all the operations that a standard 426 TRILL Switch can do. 428 One VTSD instance per tenant must be maintained, when multiple tenants 429 are connected to a TIR. The VTSD must maintain all the information 430 maintained by the RBridge on a per tenant basis. The VTSD must also take 431 care of segregating one tenant traffic from other. Each VTSD should have 432 its own nickname, If a TIR supports 10 TRILL tenants, it needs to be 433 assigned with ten TRILL nicknames and run ten copies of TRILL protocols, 434 one for each. 436 4.2. TRILL Adjacency for VPTS model 438 The VTSD must be capable of forming TRILL adjacency with other VTSDs 439 present in its peer VPTS neighbor, and also the neighbor RBridges 440 present in the TRILL sites. The procedure to form TRILL Adjacency is 441 specified in [RFC7173] and [RFC7177]. 443 4.3. MPLS encapsulation for VPTS model 445 The VPTS model uses PPP or Ethernet pseudowires for MPLS encapsulation 446 as specified in [RFC7173], and requires no changes in the packet format 447 in that RFC. 449 4.4. Loop Free provider PSN/MPLS. 451 This model isn't required to employ Split Horizon mechanism in the 452 provider PSN network, as TRILL takes care of Loop free topology using 453 Distribution Trees. Any multi-destination packet will traverse a 454 distribution tree path. All distribution trees are calculated based on 455 TRILL base protocol standard [RFC6325] as updated by [RFC7780]. 457 4.5. Frame processing. 459 This section specifies multi-destination and unicast frame processing in 460 VPTS/TIR model. 462 4.5.1. Multi-Destination Frame processing 464 Any multi-destination (unknown unicast, multicast or broadcast) packets 465 inside VTSD should be processed or forwarded through any one of the 466 distribution trees. If any multi-destination packet is received from the 467 wrong pseudowire at a VTSD, the TRILL protocol running in VTSD will 468 perform a RPF check as specified in [RFC7780] and drops the packet. 470 Pruning mechanism in Distribution Trees, as specified in [RFC6325] and 471 [RFC7780] can also be used to avoid forwarding of multi-destination data 472 packets on the branches where there are no potential destinations. 474 4.5.2. Unicast Frame processing 476 Unicast packets must be forwarded in same way they get forwarded in a 477 standard TRILL Campus as specified in [RFC6325]. If multiple equal cost 478 paths are available over pseudowires to reach destination, then VTSD 479 should be capable of doing ECMP for them. 481 5. Extensions to TRILL Over Pseudowires [RFC7173] 483 The [RFC7173] mentions how to interconnect a pair of Transparent 484 Interconnection of Lots of Links (TRILL) switch ports using pseudowires. 485 This document explains, how to connect multiple TRILL sites (not limited 486 to only two sites) using the mechanisms and encapsulations defined in 487 [RFC7173]. 489 6. VPTS Model Versus VPLS Model 491 VPLS Model uses a simpler loop breaking rule: the "split horizon" rule, 492 where a PE must not forward traffic from one PW to another in the same 493 VPLS mesh. 495 whereas the VPTS Model uses distribution Trees for loop free topology. 496 Hence the frames reach all TIRs even when any one of the pseudowires 497 fails in the mesh. 499 If equal cost paths are available to reach a site over pseudowires, VPTS 500 Model can use ECMP for processing of frames over pseudowires. 502 7. Packet processing between pseudowires 504 Whenever a packet gets received over a pseudowire, VTSD will decapsulate 505 the MPLS headers followed by checking the TRILL header. If the egress 506 nickname in the TRILL header is for a TRILL site located beyond another 507 pseudowire, then VTSD will encapsulate with new MPLS headers and send it 508 across the proper pseudowire. 510 For example in figure 3, consider that the pseudowire between TIR1 and 511 TIR2 fails, Then TIR1 will communicate with TIR2 via TIR3, whenever 512 packets which are destined to TIR3 gets received from pseudowire between 513 TIR1 and TIR3, VTSD inside TIR3 will decapsulate the MPLS headers, then 514 check the TRILL header's egress nickname field. If egress nickname is 515 destained for the RBridge in site3 then the packet will be sent to RBc, 516 if egress nickname is located at site2, VTSD will add MPLS headers for 517 the pseudowire between TIR3 and TIR2 and forward the packet on that 518 pseudowire. 520 8. Security Considerations 522 For general TRILL security considerations, see [RFC6325] 524 For transport of TRILL by Pseudowires security consideration, see 525 [RFC7173]. 527 For general VPLS security considerations, see [RFC4761] and [RFC4762] 529 Since the VPTS Model uses Distribution trees for processing of multi- 530 destination data packets, it is always advisable to have at least one 531 Distribution tree root to be located in every TRILL site. This will 532 avoid data packets getting received at TRILL sites where end-station 533 service is not enabled for that data packet. 535 9. IANA Considerations 537 This document requires no IANA actions. RFC Editor: Please delete this 538 section before publication 540 10. References 542 10.1. Normative References 544 [IS-IS] "Intermediate system to Intermediate system routeing 545 information exchange protocol for use in conjunction with 546 the Protocol for providing the Connectionless-mode Network 547 Service (ISO 8473)", ISO/IEC 10589:2002, 2002". 549 [RFC6325] Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A. 550 Ghanwani, "Routing Bridges (RBridges): Base Protocol 551 Specification", RFC 6325, DOI 10.17487/RFC6325, July 2011, 552 . 554 [RFC4761] Kompella, K., Ed., and Y. Rekhter, Ed., "Virtual Private 555 LAN Service (VPLS) Using BGP for Auto-Discovery and 556 Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007, 557 . 559 [RFC4762] Lasserre, M., Ed., and V. Kompella, Ed., "Virtual Private 560 LAN Service (VPLS) Using Label Distribution Protocol (LDP) 561 Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007, 562 . 564 [RFC7041] Balus, F., Ed., Sajassi, A., Ed., and N. Bitar, Ed., 565 "Extensions to the Virtual Private LAN Service (VPLS) 566 Provider Edge (PE) Model for Provider Backbone Bridging", 567 RFC 7041, DOI 10.17487/RFC7041, November 2013, 568 . 570 [RFC7173] Yong, L., Eastlake 3rd, D., Aldrin, S., and J. Hudson, 571 "Transparent Interconnection of Lots of Links (TRILL) 572 Transport Using Pseudowires", RFC 7173, DOI 573 10.17487/RFC7173, May 2014, . 576 [RFC7177] Eastlake 3rd, D., Perlman, R., Ghanwani, A., Yang, H., and 577 V. Manral, "Transparent Interconnection of Lots of Links 578 (TRILL): Adjacency", RFC 7177, DOI 10.17487/RFC7177, May 579 2014, . 581 [RFC7780] Eastlake 3rd, D., Zhang, M., Perlman, R., Banerjee, A., 582 Ghanwani, A., and S. Gupta, "Transparent Interconnection 583 of Lots of Links (TRILL): Clarifications, Corrections, and 584 Updates", RFC 7780, DOI 10.17487/RFC7780, February 2016, 585 . 587 10.2. Informative References 589 [RFC4026] Andersson, L. and T. Madsen, "Provider Provisioned Virtual 590 Private Network (VPN) Terminology", RFC 4026, DOI 591 10.17487/RFC4026, March 2005, . 594 [RFC4664] Andersson, L., Ed., and E. Rosen, Ed., "Framework for 595 Layer 2 Virtual Private Networks (L2VPNs)", RFC 4664, DOI 596 10.17487/RFC4664, September 2006, . 599 [RFC7172] Eastlake 3rd, D., Zhang, M., Agarwal, P., Perlman, R., and 600 D. Dutt, "Transparent Interconnection of Lots of Links 601 (TRILL): Fine-Grained Labeling", RFC 7172, DOI 602 10.17487/RFC7172, May 2014, . 605 Acknowledgements 606 The contributions of Andrew G. Malis is gratefully acknowledged in 607 improving the quality of this document. 609 Authors' Addresses 611 Mohammed Umair 612 IPInfusion 613 RMZ Centennial 614 Mahadevapura Post 615 Bangalore - 560048 India 617 EMail: mohammed.umair2@gmail.com 619 Kingston Smiler Selvaraj 620 IPInfusion 621 RMZ Centennial 622 Mahadevapura Post 623 Bangalore - 560048 India 625 EMail: kingstonsmiler@gmail.com 627 Donald E. Eastlake 3rd 628 Huawei Technologies 629 155 Beaver Street 630 Milford, MA 01757 631 USA 633 Phone: +1-508-333-2270 634 EMail: d3e3e3@gmail.com 636 Lucy Yong 637 Huawei Technologies 638 5340 Legacy Drive 639 Plano, TX 75024 640 USA 642 Phone: +1-469-227-5837 643 EMail: lucy.yong@huawei.com