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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) ** Obsolete normative reference: RFC 4970 (Obsoleted by RFC 7770) Summary: 1 error (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group A. Lindem, Ed. 3 Internet-Draft N. Shen 4 Obsoletes: 4970 (if approved) J. Vasseur 5 Intended status: Standards Track Cisco Systems 6 Expires: February 22, 2016 R. Aggarwal 7 Arktan 8 S. Shaffer 9 Akamai 10 August 21, 2015 12 Extensions to OSPF for Advertising Optional Router Capabilities 13 draft-ietf-ospf-rfc4970bis-02.txt 15 Abstract 17 It is useful for routers in an OSPFv2 or OSPFv3 routing domain to 18 know the capabilities of their neighbors and other routers in the 19 routing domain. This document proposes extensions to OSPFv2 and 20 OSPFv3 for advertising optional router capabilities. The Router 21 Information (RI) Link State Advertisement (LSA) is defined for this 22 purpose. In OSPFv2, the RI LSA will be implemented with an opaque 23 LSA type ID. In OSPFv3, the RI LSA will be implemented with a unique 24 LSA type function code. In both protocols, the RI LSA can be 25 advertised at any of the defined flooding scopes (link, area, or 26 autonomous system (AS)). This document obsoletes RFC 4970 by 27 providing a revised specification including support for advertisement 28 of multiple instances of the RI LSA and a TLV for functional 29 capabilities. 31 Status of This Memo 33 This Internet-Draft is submitted in full conformance with the 34 provisions of BCP 78 and BCP 79. 36 Internet-Drafts are working documents of the Internet Engineering 37 Task Force (IETF). Note that other groups may also distribute 38 working documents as Internet-Drafts. The list of current Internet- 39 Drafts is at http://datatracker.ietf.org/drafts/current/. 41 Internet-Drafts are draft documents valid for a maximum of six months 42 and may be updated, replaced, or obsoleted by other documents at any 43 time. It is inappropriate to use Internet-Drafts as reference 44 material or to cite them other than as "work in progress." 46 This Internet-Draft will expire on February 22, 2016. 48 Copyright Notice 50 Copyright (c) 2015 IETF Trust and the persons identified as the 51 document authors. All rights reserved. 53 This document is subject to BCP 78 and the IETF Trust's Legal 54 Provisions Relating to IETF Documents 55 (http://trustee.ietf.org/license-info) in effect on the date of 56 publication of this document. Please review these documents 57 carefully, as they describe your rights and restrictions with respect 58 to this document. Code Components extracted from this document must 59 include Simplified BSD License text as described in Section 4.e of 60 the Trust Legal Provisions and are provided without warranty as 61 described in the Simplified BSD License. 63 Table of Contents 65 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 66 1.1. Requirements Notation . . . . . . . . . . . . . . . . . . 3 67 1.2. Summary of Changes from RFC 4970 . . . . . . . . . . . . 3 68 2. OSPF Router Information (RI) LSA . . . . . . . . . . . . . . 3 69 2.1. OSPFv2 Router Information (RI) Opaque LSA . . . . . . . . 4 70 2.2. OSPFv3 Router Information (RI) Opaque LSA . . . . . . . . 6 71 2.3. OSPF Router Informational Capabilities TLV . . . . . . . 6 72 2.4. Assigned OSPF Router Informational Capability Bits . . . 7 73 2.5. OSPF Router Functional Capabilities TLV . . . . . . . . . 8 74 2.6. Flooding Scope of the Router Information LSA . . . . . . 9 75 3. Security Considerations . . . . . . . . . . . . . . . . . . . 10 76 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 77 5. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 78 5.1. Normative References . . . . . . . . . . . . . . . . . . 12 79 5.2. Informative References . . . . . . . . . . . . . . . . . 13 80 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 13 81 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 83 1. Introduction 85 It is useful for routers in an OSPFv2 [OSPF] or OSPFv3 [OSPFV3] 86 routing domain to know the capabilities of their neighbors and other 87 routers in the routing domain. This can be useful for both the 88 advertisement and discovery of OSPFv2 and OSPFv3 capabilities. 89 Throughout this document, OSPF will be used when the specification is 90 applicable to both OSPFv2 and OSPFv3. Similarly, OSPFv2 or OSPFv3 91 will be used when the text is protocol specific. 93 OSPF uses the options field in LSAs and hello packets to advertise 94 optional router capabilities. In the case of OSPFv2, all the bits in 95 this field have been allocated so additional optional capabilities 96 cannot be advertised. This document describes extensions to OSPF to 97 advertise these optional capabilities via opaque LSAs in OSPFv2 and 98 LSAs with a unique type in OSPFv3. For existing OSPF capabilities, 99 backward-compatibility issues dictate that this advertisement is used 100 primarily for informational purposes. For future OSPF extensions, 101 this advertisement MAY be used as the sole mechanism for 102 advertisement and discovery. 104 This document obsoletes RFC 4970 by providing a revised specification 105 including support for advertisement of multiple instances of the RI 106 LSA and a TLV for functional capabilities. 108 1.1. Requirements Notation 110 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 111 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 112 document are to be interpreted as described in [RFC-KEYWORDS]. 114 1.2. Summary of Changes from RFC 4970 116 This document includes the following changes from RFC 4970 [RFC4970]: 118 1. The main change is that an OSPF router will be able to advertise 119 multiple instances of the OSPF Router Information LSA. This 120 change permeates through much of the document 122 2. Additionally, Section 2.5 includes an additional TLV for 123 functional capabilities. This is in contrast to the existing TLV 124 which is used to advertise capabilities for informational 125 purposes only. 127 3. Finally, references have been updated for drafts that have become 128 RFCs and RFCs that have been obsoleted since the publication of 129 RFC 4970. 131 2. OSPF Router Information (RI) LSA 133 OSPFv2 routers will advertise a link scoped, area-scoped, or AS- 134 scoped Opaque-LSA [OPAQUE]. The OSPFv2 Router Information (RI) LSA 135 has an Opaque type of 4 and the Opaque ID is the RI LSA instance ID. 136 The first Opaque ID, i.e., 0, should always contain the Router 137 Informational Capabilities TLV and, if advertised, the Router 138 Functional Capabilities TLV. RI LSAs subsequence to the first can be 139 used for information that doesn't fit in the first instance. 141 2.1. OSPFv2 Router Information (RI) Opaque LSA 143 OSPFv2 routers will advertise a link scoped, area-scoped, or AS- 144 scoped Opaque-LSA [OPAQUE]. The OSPFv2 Router Information LSA has an 145 Opaque type of 4 and Opaque ID specifies the LSA instance ID with the 146 first instance always having an Instance ID of 0. 148 0 1 2 3 149 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 1 150 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 151 | LS age | Options | 9, 10, or 11 | 152 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 153 | 4 | Opaque ID (Instance ID) | 154 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 155 | Advertising Router | 156 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 157 | LS sequence number | 158 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 159 | LS checksum | length | 160 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 161 | | 162 +- TLVs -+ 163 | ... | 165 OSPFv2 Router Information Opaque LSA 167 The format of the TLVs within the body of an RI LSA is the same as 168 the format used by the Traffic Engineering Extensions to OSPF [TE]. 169 The LSA payload consists of one or more nested Type/Length/Value 170 (TLV) triplets. The format of each TLV is: 172 0 1 2 3 173 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 1 174 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 175 | Type | Length | 176 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 177 | Value... | 178 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 TLV Format 182 The Length field defines the length of the value portion in octets 183 (thus a TLV with no value portion would have a length of 0). The TLV 184 is padded to 4-octet alignment; padding is not included in the length 185 field (so a 3-octet value would have a length of 3, but the total 186 size of the TLV would be 8 octets). Nested TLVs are also 32-bit 187 aligned. For example, a 1-byte value would have the length field set 188 to 1, and 3 octets of padding would be added to the end of the value 189 portion of the TLV. The padding is composed of zeros. Unrecognized 190 types are ignored. 192 2.2. OSPFv3 Router Information (RI) Opaque LSA 194 The OSPFv3 Router Information LSA has a function code of 12 while the 195 S1/S2 bits are dependent on the desired flooding scope for the LSA. 196 The U bit will be set indicating that the OSPFv3 RI LSA should be 197 flooded even if it is not understood. The Link State ID (LSID) value 198 for this LSA is the instance ID. The first instance ID, i.e., 0, 199 should always contain the Router Informational Capabilities TLV and, 200 if advertised, the Router Functional Capabilities TLV. OSPFv3 Router 201 Information LSAs subsequence to the first can be used for information 202 that doesn't fit in the first instance. OSPFv3 routers MAY advertise 203 multiple RIs LSA per flooding scope. 205 0 1 2 3 206 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 1 207 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 208 | LS age |1|S12| 12 | 209 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 210 | Link State ID (Instance ID) | 211 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 212 | Advertising Router | 213 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 214 | LS sequence number | 215 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 216 | LS checksum | Length | 217 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 218 | | 219 +- TLVs -+ 220 | ... | 222 OSPFv3 Router Information LSA 224 The format of the TLVs within the body of an RI LSA is as defined in 225 Section 2.1 227 When a new Router Information LSA TLV is defined, the specification 228 MUST explicitly state whether the TLV is applicable to OSPFv2 only, 229 OSPFv3 only, or both OSPFv2 and OSPFv3. 231 2.3. OSPF Router Informational Capabilities TLV 233 The first defined TLV in the body of an RI LSA is the Router 234 Informational Capabilities TLV. An OSPF router advertising an OSPF 235 RI LSA MAY include the Router Informational Capabilities TLV. If 236 included, it MUST be the first TLV in the first instance of the OSPF 237 RI LSA. Additionally, the TLV MUST accurately reflect the OSPF 238 router's capabilities in the scope advertised. However, the 239 informational capabilities advertised have no impact on the OSPF's 240 operation -- they are advertised purely for informational purposes. 242 The format of the Router Informational Capabilities TLV is as 243 follows: 245 0 1 2 3 246 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 1 247 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 248 | Type | Length | 249 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 250 | Informational Capabilities | 251 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 Type A 16-bit field set to 1. 255 Length A 16-bit field that indicates the length of the value 256 portion in octets and will be a multiple of 4 octets 257 dependent on the number of capabilities advertised. 258 Initially, the length will be 4, denoting 4 octets of 259 informational capability bits. 261 Value A variable length sequence of capability bits rounded 262 to a multiple of 4 octets padded with undefined bits. 263 Initially, there are 4 octets of capability bits. Bits 264 are numbered left-to-right starting with the most 265 significant bit being bit 0. 267 OSPF Router Informational Capabilities TLV 269 The Router Informational Capabilities TLV MAY be followed by optional 270 TLVs that further specify a capability. 272 2.4. Assigned OSPF Router Informational Capability Bits 274 The following informational capability bits are assigned: 276 Bit Capabilities 278 0 OSPF graceful restart capable [GRACE] 279 1 OSPF graceful restart helper [GRACE] 280 2 OSPF Stub Router support [STUB] 281 3 OSPF Traffic Engineering support [TE] 282 4 OSPF point-to-point over LAN [P2PLAN] 283 5 OSPF Experimental TE [EXP-TE] 284 6-31 Unassigned (Standards Action) 286 OSPF Router Informational Capabilities Bits 288 References for [GRACE], [STUB], [TE], [P2PLAN], and [EXP-TE] are 289 included herein. 291 2.5. OSPF Router Functional Capabilities TLV 293 This specification also defines the Router Functional Capabilities 294 TLV for advertisement within the OSPF Router Information LSA. An 295 OSPF router advertising an OSPF RI LSA MAY include the Router 296 Functional Capabilities TLV. If included, it MUST be the included in 297 the first instance of the LSA. Additionally, the TLV MUST be used to 298 reflect OSPF router functional capabilities. If the TLV is not 299 included or the length doesn't include the assigned OSPF functional 300 capability bit, the corresponding OSPF functional capability is 301 implicitly advertised as not being supported by the advertising OSPF 302 router. 304 The format of the Router Functional Capabilities TLV is as follows: 306 0 1 2 3 307 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 1 308 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 309 | Type | Length | 310 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 311 | Functional Capabilities | 312 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 314 Type A 16-bit field set to IANA TBD. 316 Length A 16-bit field that indicates the length of the value 317 portion in octets and will be a multiple of 4 octets 318 dependent on the number of capabilities advertised. 319 Initially, the length will be 4, denoting 4 octets of 320 informational capability bits. 322 Value A variable length sequence of capability bits rounded 323 to a multiple of 4 octets padded with undefined bits. 324 Initially, there are 4 octets of capability bits. Bits 325 are numbered left-to-right starting with the most 326 significant bit being bit 0. 328 OSPF Router Functional Capabilities TLV 330 The Router Functional Capabilities TLV MAY be followed by optional 331 TLVs that further specify a capability. In contrast to the Router 332 Informational Capabilities TLV, the OSPF extensions advertised in 333 this TLV MAY be used by other OSPF routers to dictate protocol 334 operation. The specifications for functional capabilities advertised 335 in this TLV MUST describe protocol behavior and address backward 336 compatibility. 338 2.6. Flooding Scope of the Router Information LSA 340 The flooding scope for a Router Information LSA is determined by the 341 LSA type. For OSPFv2, type 9 (link-scoped), type 10 (area-scoped), 342 or a type 11 (AS-scoped) opaque LSA may be flooded. For OSPFv3, the 343 S1 and S2 bits in the LSA type determine the flooding scope. If AS- 344 wide flooding scope is chosen, the originating router should also 345 advertise area-scoped LSA(s) into any attached Not-So-Stubby Area 346 (NSSA) area(s). An OSPF router MAY advertise different capabilities 347 when both NSSA area scoped LSA(s) and an AS-scoped LSA are 348 advertised. This allows functional capabilities to be limited in 349 scope. For example, a router may be an area border router but only 350 support traffic engineering (TE) in a subset of its attached areas. 352 The choice of flooding scope is made by the advertising router and is 353 a matter of local policy. The originating router MAY advertise 354 multiple RI LSAs with the same instance ID as long as the flooding 355 scopes differ. TLV flooding scope rules will be specified on a per- 356 TLV basis and MUST be specified in the accompanying specifications 357 for future Router Information LSA TLVs. 359 3. Security Considerations 361 This document describes both a generic mechanism for advertising 362 router capabilities and a TLV for advertising informational and 363 functional capability bits. The capability TLVs are less critical 364 than the topology information currently advertised by the base OSPF 365 protocol. The security considerations for the generic mechanism are 366 dependent on the future application and, as such, should be described 367 as additional capabilities are proposed for advertisement. Security 368 considerations for the base OSPF protocol are covered in [OSPF] and 369 [OSPFV3]. 371 4. IANA Considerations 373 The following IANA assignment was made from an existing registry: 375 The OSPFv2 opaque LSA type 4 has been reserved for the OSPFv2 RI 376 opaque LSA. 378 The following registries have been defined for the following 379 purposes: 381 1. Registry for OSPFv3 LSA Function Codes - This top-level registry 382 will be comprised of the fields Value, LSA function code name, 383 and Document Reference. The OSPFv3 LSA function code is defined 384 in section A.4.2.1 of [OSPFV3]. The OSPFv3 LSA function code 12 385 has been reserved for the OSPFv3 Router Information (RI) LSA. 387 +-----------+-------------------------------------+ 388 | Range | Assignment Policy | 389 +-----------+-------------------------------------+ 390 | 0 | Reserved (not to be assigned) | 391 | | | 392 | 1-9 | Already assigned | 393 | | | 394 | 10-11 | Unassigned (Standards Action) | 395 | | | 396 | 12 | OSPFv3 RI LSA (Assigned herein) | 397 | | | 398 | 13-255 | Unassigned (Standards Action) | 399 | | | 400 | 256-8175 | Reserved (No assignments) | 401 | | | 402 | 8176-8183 | Experimentation (No assignments) | 403 | | | 404 | 8184-8191 | Vendor Private Use (No assignments) | 405 +-----------+-------------------------------------+ 407 OSPFv3 LSA Function Codes 409 * OSPFv3 LSA function codes in the range 256-8175 are not to be 410 assigned at this time. Before any assignments can be made in 411 this range, there MUST be a Standards Track RFC that specifies 412 IANA Considerations that cover the range being assigned. 414 * OSPFv3 LSA function codes in the range 8176-8181 are for 415 experimental use; these will not be registered with IANA and 416 MUST NOT be mentioned by RFCs. 418 * OSPFv3 LSAs with an LSA Function Code in the Vendor Private 419 Use range 8184-8191 MUST include the Vendor Enterprise Code as 420 the first 4 octets following the 20 octets of LSA header. 422 * If a new LSA Function Code is documented, the documentation 423 MUST include the valid combinations of the U, S2, and S1 bits 424 for the LSA. It SHOULD also describe how the Link State ID is 425 to be assigned. 427 2. Registry for OSPF RI TLVs - This top-level registry will be 428 comprised of the fields Value, TLV Name, and Document Reference. 429 The value of 1 for the informational capabilities TLV is defined 430 herein. The value IANA TBD for the functional capabilities TLV 431 is also defined herein. 433 +-------------+-----------------------------------+ 434 | Range | Assignment Policy | 435 +-------------+-----------------------------------+ 436 | 0 | Reserved (not to be assigned) | 437 | | | 438 | 1 | Informational Capabilities | 439 | | | 440 | TBD | Functional Capabilities | 441 | | | 442 | 2-32767 | Unassigned (Standards Action) | 443 | | | 444 | 32768-32777 | Experimentation (No assignments) | 445 | | | 446 | 32778-65535 | Reserved (Not to be assigned) | 447 +-----------+-------------------------------------+ 449 OSPF RI TLVs 451 * Types in the range 32768-32777 are for experimental use; these 452 will not be registered with IANA and MUST NOT be mentioned by 453 RFCs. 455 * Types in the range 32778-65535 are reserved and are not to be 456 assigned at this time. Before any assignments can be made in 457 this range, there MUST be a Standards Track RFC that specifies 458 IANA Considerations that covers the range being assigned. 460 3. Registry for OSPF Router Informational Capability Bits - This 461 sub-registry of the OSPF RI TLV registry will be comprised of the 462 fields Bit Number, Capability Name, and Document Reference. The 463 values are defined in Section 2.4. All Router Informational 464 Capability TLV additions are to be assigned through standards 465 action. 467 4. Registry for OSPF Router Functional Capability Bits - This sub- 468 registry of the OSPF RI TLV registry will be comprised of the 469 fields Bit Number, Capability Name, and Document Reference. 470 Initially, the sub-registry will be empty but will be available 471 for future capabilities. All Router Functional Capability TLV 472 additions are to be assigned through standards action. 474 5. References 476 5.1. Normative References 478 [OPAQUE] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The 479 OSPF Opaque LSA Option", RFC 5250, July 2008. 481 [OSPF] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. 483 [OSPFV3] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF 484 for IPv6", RFC 5340, July 2008. 486 [RFC-KEYWORDS] 487 Bradner, S., "Key words for use in RFC's to Indicate 488 Requirement Levels", BCP 14, RFC 2119, March 1997. 490 [RFC4970] Lindem, A., Shen, N., Vasseur, J., Aggarwal, R., and S. 491 Shaffer, "Extensions to OSPF for Advertising Optional 492 Router Capabilities", RFC 4970, July 2007. 494 [TE] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering 495 Extensions to OSPF", RFC 3630, September 2003. 497 5.2. Informative References 499 [EXP-TE] Srisuresh, P. and P. Joseph, "OSPF-xTE: Experimental 500 Extension to OSPF for Traffic Engineering", RFC 4973, July 501 2007. 503 [GRACE] Moy, J., Pillay-Esnault, P., and A. Lindem, "Graceful OSPF 504 Restart", RFC 3623, November 2003. 506 [P2PLAN] Shen, N. and A. Zinin, "Point-to-point operation over LAN 507 in link-state routing protocols", RFC 5309, October 2008. 509 [STUB] Retana, A., Nguyen, L., White, R., Zinin, A., and D. 510 McPherson, "OSPF Stub Router Advertisement", RFC 6987, 511 September 2013. 513 Appendix A. Acknowledgments 515 The idea for this work grew out of a conversation with Andrew Partan 516 and we would like to thank him for his contribution. The authors 517 would like to thanks Peter Psenak for his review and helpful comments 518 on early versions of the document. 520 Comments from Abhay Roy, Vishwas Manral, Vivek Dubey, and Adrian 521 Farrel have been incorporated into later versions. 523 Thanks to Chris Bowers for review of the BIS version of the draft. 525 The RFC text was produced using Marshall Rose's xml2rfc tool. 527 Authors' Addresses 529 Acee Lindem (editor) 530 Cisco Systems 531 301 Midenhall Way 532 Cary, NC 27513 533 USA 535 Email: acee@cisco.com 537 Naiming Shen 538 Cisco Systems 539 225 West Tasman Drive 540 San Jose, CA 95134 541 USA 543 Email: naiming@cisco.com 545 Jean-Philippe Vasseur 546 Cisco Systems 547 1414 Massachusetts Avenue 548 Boxborough, MA 01719 549 USA 551 Email: jpv@cisco.com 553 Rahul Aggarwal 554 Arktan 556 Email: raggarwa_1@yahoo.com 558 Scott Shaffer 559 Akamai 560 8 Cambridge Center 561 Cambridge, MA 02142 562 USA 564 Email: sshaffer@akamai.com