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Checking references for intended status: Experimental ---------------------------------------------------------------------------- ** Obsolete normative reference: RFC 4970 (Obsoleted by RFC 7770) == Outdated reference: A later version (-12) exists of draft-ietf-pce-pcep-domain-sequence-05 Summary: 1 error (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 PCE Working Group D. Dhody 3 Internet-Draft U. Palle 4 Intended status: Experimental Huawei Technologies India Pvt Ltd 5 Expires: March 19, 2015 September 15, 2014 7 OSPF Protocol Extensions for Boundary Node Discovery (BND) 8 draft-dhody-pce-bn-discovery-ospf-09 10 Abstract 12 The Path Computation Element (PCE) may be used for computing multi- 13 domain (Area or AS) Multiprotocol Label Switching (MPLS) and 14 Generalized MPLS (GMPLS) Traffic Engineered (TE) Label Switch Path 15 (LSP). 17 In this circumstance, it is highly desirable to be able to 18 dynamically and automatically discover a set of Boundary Nodes (BN) 19 along with their domain information in a simple way. For that 20 purpose, this document defines extensions to the Open Shortest Path 21 First (OSPF) routing protocol for the advertisement of Boundary Node 22 (BN) Discovery information within an OSPF area or within the entire 23 OSPF routing domain. 25 Status of This Memo 27 This Internet-Draft is submitted 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). Note that other groups may also distribute 32 working documents as Internet-Drafts. The list of current Internet- 33 Drafts is at http://datatracker.ietf.org/drafts/current/. 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 This Internet-Draft will expire on March 19, 2015. 42 Copyright Notice 44 Copyright (c) 2014 IETF Trust and the persons identified as the 45 document authors. All rights reserved. 47 This document is subject to BCP 78 and the IETF Trust's Legal 48 Provisions Relating to IETF Documents 49 (http://trustee.ietf.org/license-info) in effect on the date of 50 publication of this document. Please review these documents 51 carefully, as they describe your rights and restrictions with respect 52 to this document. Code Components extracted from this document must 53 include Simplified BSD License text as described in Section 4.e of 54 the Trust Legal Provisions and are provided without warranty as 55 described in the Simplified BSD License. 57 Table of Contents 59 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 60 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 61 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 62 3. Applications . . . . . . . . . . . . . . . . . . . . . . . . 4 63 4. Existing Mechanisms . . . . . . . . . . . . . . . . . . . . . 6 64 4.1. OSPF LSA . . . . . . . . . . . . . . . . . . . . . . . . 6 65 4.2. Inter-AS TE Link . . . . . . . . . . . . . . . . . . . . 6 66 4.3. OSPF Area Topology . . . . . . . . . . . . . . . . . . . 8 67 5. Other Considerations . . . . . . . . . . . . . . . . . . . . 8 68 5.1. Static Configurations . . . . . . . . . . . . . . . . . . 8 69 5.2. Importance of Domain Information along with BNs . . . . . 8 70 5.3. Relationship to Domain-Sequence . . . . . . . . . . . . . 9 71 6. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 9 72 6.1. Boundary Node (BN) Discovery Information . . . . . . . . 9 73 6.2. Flooding Scope . . . . . . . . . . . . . . . . . . . . . 9 74 7. The OSPF BND TLV . . . . . . . . . . . . . . . . . . . . . . 9 75 7.1. BN-ADDRESS Sub-TLV . . . . . . . . . . . . . . . . . . . 10 76 7.2. BN-DOMAIN Sub-TLV . . . . . . . . . . . . . . . . . . . . 11 77 8. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 12 78 9. Backward Compatibility . . . . . . . . . . . . . . . . . . . 13 79 10. Impact on Network . . . . . . . . . . . . . . . . . . . . . . 13 80 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 81 11.1. OSPF TLV . . . . . . . . . . . . . . . . . . . . . . . . 13 82 12. Security Considerations . . . . . . . . . . . . . . . . . . . 14 83 13. Manageability Considerations . . . . . . . . . . . . . . . . 14 84 14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14 85 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 86 15.1. Normative References . . . . . . . . . . . . . . . . . . 14 87 15.2. Informative References . . . . . . . . . . . . . . . . . 15 89 1. Introduction 91 This document defines extensions to OSPFv2 [RFC2328] and OSPFv3 92 [RFC5340] to allow a boundary node in an OSPF routing domain to 93 advertise its location, along with domain information. 95 Generic capability advertisement mechanisms for OSPF are defined in 96 [RFC4970]. These allow a router to advertise its capabilities within 97 an OSPF area or an entire OSPF routing domain. This document 98 leverages this generic capability advertisement mechanism to fully 99 satisfy the dynamic BN discovery. 101 This document defines a new TLV (named the Boundary Node Discovery 102 TLV (BND TLV)) to be carried within the OSPF Router Information LSA 103 ([RFC4970]). 105 The Boundary Node information advertised is detailed in Section 6. 106 Protocol extensions and procedures are defined in Section 7 and 107 Section 8. 109 A detailed description about the need for auto discovery of Boundary 110 Nodes (BN) and thier domains is also provided in this document. 112 The OSPF extensions defined in this document allow for Boundary Node 113 discovery within an OSPF routing domain. Boundary Node can be an 114 Area Border Router (ABR) or Autonomous System Border Router (ASBR). 116 1.1. Requirements Language 118 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 119 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 120 document are to be interpreted as described in [RFC2119]. 122 2. Terminology 124 The following terminology is used in this document. 126 ABR: OSPF Area Border Router. Routers used to connect two IGP 127 areas. 129 AS: Autonomous System. 131 ASBR: Autonomous System Border Router. Router used to connect 132 together ASes of the same or different service providers via one 133 or more inter-AS links 135 BN: A boundary node is either an ABR in the context of inter-area 136 Traffic Engineering or an ASBR in the context of inter-AS Traffic 137 Engineering. 139 BND: Boundary Node Discovery 141 BRPC: Backward Recursive Path Computation 143 Domain: Any collection of network elements within a common sphere of 144 address management or path computational responsibility. Examples 145 of domains include Interior Gateway Protocol (IGP) areas and 146 Autonomous Systems (ASs). 148 H-PCE: Hierarchical PCE. 150 IGP: Interior Gateway Protocol. Either of the two routing 151 protocols, Open Shortest Path First (OSPF) or Intermediate System 152 to Intermediate System (IS-IS). 154 LSA: Link State Advertisement. 156 OSPF: Open Shortest Path First. 158 PCE: Path Computation Element. An entity (component, application, 159 or network node) that is capable of computing a network path or 160 route based on a network graph and applying computational 161 constraints. 163 TLV: Type-Length-Variable data encoding. 165 3. Applications 167 Backward Recursive Path Computation (BRPC) procedure as defined in 168 [RFC5441], requires Path Computation Element (PCE) [RFC4655] to be 169 aware of the Boundary Nodes (BN) for the inter-domain path 170 computation. This information would be either statically configured 171 at PCE or learned via some mechanism, as listed in Section 4. 173 In case of static configuration, as shown in the Figure 1, incase of 174 OSPF Area0, configuration of BNs at PCE5 is extensive. BRPC 175 procedure guarantees a best path only if BNs are selected correctly, 176 any change in BNs at run time may lead to sub-optimal path. Also 177 Administrator need to configure ABR / ASBR ID in such a way that it 178 is reachable from all the domains, BND TLV can take care of this 179 automatically. 181 +--------------------+ 182 | +-----+| 183 | Area 2 | PCE2|| 184 | +-----+| 185 | | 186 | | 187 | BN4+----+ | 188 +--------+----+------+ 189 +----------+----+---------+ 190 | +----+ | 191 | | 192 | | 193 | | 194 +---------------+ | |+----------------+ 195 | BN1 | | || BN5 | 196 | +-+-++ +++--+ | 197 | | | || ||| | | 198 | +-+-++ +++--+ | 199 | | | || | 200 | BN2 | | || BN6 | 201 | +-+-++ Area 0 +++--+ | 202 | Area 1 | | || ||| | Area 3 | 203 | +-+-++ +++--+ | 204 | | | || | 205 | BN3 | | +-----+ || BN7 | 206 |+-----+ +-+-++ | PCE5| +++--+ +-----+ | 207 || PCE1| | | || +-----+ ||| | | PCE3| | 208 |+-----+ +-+-++ +++--+ +-----+ | 209 | | | || | 210 +---------------+ | |+----------------+ 211 | | 212 | | 213 | +----+ | 214 +----------+----+---------+ 215 +--------+----+------+ 216 | BN8 +----+ | 217 | | 218 | | 219 | Area 4 +-----+| 220 | | PCE4|| 221 | +-----+| 222 +--------------------+ 224 Figure 1: OSPF Area Topology 226 The problems with existing mechanism to discover Boundary nodes are 227 listed in Section 4. 229 Hierarchal PCE (H-PCE) [RFC6805] mechanim MAY require a parent PCE to 230 be aware of child domain's boundary node, child PCE in any case 231 should be aware of all its boundary nodes and can use mechnims as 232 described in this document. 234 4. Existing Mechanisms 236 4.1. OSPF LSA 238 o E bit and B bit of Router LSA defined in [RFC2328] can help in 239 finding a router acting as ABR/ASBR but there is no way to find 240 out the domain information of this ABR/ASBR. As stated in 241 Section 5.2, Selection of correct BN is based on domain and thus 242 it is ineffective. 244 o Selection of ABR based on summary LSA or ASBR based on AS-external 245 LSA is not a good idea, first it requires PCE to look into the 246 OSPF core data structure - Link State Database (LSDB) thus adding 247 to coupling, second it MAY require Border Gateway Protocol (BGP) 248 routes to be redistributed into OSPF which is also not a good 249 network design principle. 251 4.2. Inter-AS TE Link 253 o [RFC5392] specifies how to advertise TE properties of inter-AS 254 links; through which ASBR and remote AS can be discovered, but ABR 255 and their domain information cannot be discovered via above RFC. 257 o AS is made up of multiple Area, there maybe a need to clearly 258 identify a BN by combination of both AS number and Area-id. Refer 259 [DOMAIN-SEQ]. 261 o AS shown in below figure, just the knowledge of AS 100 and AS 200 262 is not sufficient, the BN should have both AS and Area 263 information. The area information cannot be provided by 264 [RFC5392]. 266 | 267 | +-------------+ +----------------+ 268 | |Area 2 | |Area 4 | 269 | | +--+| | +--+ | 270 | | | || | | | | 271 | | +--+ +--+| | +--+ +--+ | 272 | | | | | | | | | 273 | | *--+ | | +--+ | 274 | | / +--+ | | +--+ | 275 | |/ | | | | | | | 276 | / +--+ | | +--+ +--+ | 277 | /| +--+ |+--------------+| | | | 278 |/ | | | ++-+ +-++ +--+ | 279 +-------------+/ | +--+ || | | || | 280 | /| | ++-+ +-++ | 281 | +--*|| +-------------+| |+----------------+ 282 | | ||| | +--+ | 283 | +--+|| | | | | 284 | +--+ || | +--+ | 285 | | | || | | 286 | +--+ || | | 287 | || | +--+ | 288 |+--+ || | | | | 289 || | || | +--+ | 290 |+--+ || | | 291 | || | +--+ | 292 | +--+ || +------------+ | | | |+----------------+ 293 | | | || |Area 3 +-++ +--+ +-++ Area 5 | 294 | +--+ || | | || | || | 295 | || | +-++ +-++ | 296 | +--+|| | +--+ | | Area 0 || +--+ | 297 | | ||| | | | | +--------------+| | | | 298 | +--*|| | +--+ | | +--+ | 299 | \| | | | +--+ | 300 |Area 1 |\ | +--+ | | +--+ | | | 301 +-------------+|\ | | | | | | | +--+ | 302 | \| +--+ +--+ | +--+ | 303 | \ | | | | 304 | |\ +--+ | +--+ | 305 | | \ +--+ | | | | | 306 | | \| | | | +--+ | 307 | | *--+ | | | 308 | | | | | 309 | +------------+ +----------------+ 310 | 311 | 312 As 100 | AS 200 313 | 315 4.3. OSPF Area Topology 317 o Consider OSPF topology as shown in Figure 1, One can make a 318 generalization that all ABR connects to Area 0, and one doesnt 319 need the area information. 321 o But as per [RFC3509], there are alternative interpretaion of ABR, 322 which needs to be considered. If there is a connectivity between 323 Area 1 and Area 2 directly that needs to be considered. In the 324 scope of path computation. it is not correct to force all paths to 325 go through area 0, irrespective of actual topology. 327 . . 328 . Area 0 . 329 +--+ +--+ 330 ..|R1|.. ..|R2|.. 331 . +--+ .. +--+ . 332 . .. . 333 . +--+ . 334 . Area1 |R3| Area2 . 335 . +--+ +--+ . 336 . .. |R4| . 337 . . . +--+ . 338 ....... ....... 340 5. Other Considerations 342 5.1. Static Configurations 344 A simple solution would be to configure BNs (ABR and ASBR) at PCE(s) 345 along with their domain information. As this information is fairly 346 static this could work in simple situations. But as PCE are being 347 used in bigger and multiple domains, any sort of static 348 configurations would put extra effort on the system administrator. 349 Selection of correct BNs is the core of any inter-domain path 350 computation procedure, this information should be dynamically learned 351 and maintained. 353 5.2. Importance of Domain Information along with BNs 355 There are methods to learn BNs dynamically from IGP, but the 356 knowledge of neighboring-domains is not possible to obtain. Without 357 this the correct BN based on the domain-path can not be selected. 358 [RFC5441] mentions: 360 "Note that PCE(i) only considers the entry BNs of domain(i), i.e., 361 only the BNs that provide connectivity from domain(i-1). In other 362 words, the set BN-en(k,i) is only made of those BNs that provide 363 connectivity from domain (i-1) to domain(i)." 365 This selection of correct BNs providing connectivity between correct 366 domains cannot be made by the information obtained from IGP. Without 367 the correct selection we would not be following [RFC5441]. 369 5.3. Relationship to Domain-Sequence 371 [DOMAIN-SEQ] provides a standard representation of Domain Sequence in 372 all deployment scenarios. The Domain Information carried in the BN- 373 DOMAIN sub-tlv is same as the sub-objects inside the domain sequence. 375 6. Overview 377 6.1. Boundary Node (BN) Discovery Information 379 The BN discovery information is composed of: 381 o The BN location: an IPv4 and/or IPv6 address that is used to reach 382 the BN. It is RECOMMENDED to use an address that is always 383 reachable from all connected domains; 385 o The set of two or more Domain(s) into which the BN has 386 connectivity; 388 Changes in BN discovery information may occur as a result of BN 389 configuration update or domain status change. 391 6.2. Flooding Scope 393 The flooding scope for BN information advertised through OSPF can be 394 limited to OSPF area(s) the BN belongs to, or can be extended across 395 the entire OSPF routing domain. 397 7. The OSPF BND TLV 399 The OSPF BN Discovery TLV (BND TLV) contains a non-ordered set of 400 sub-TLVs. 402 The format of the OSPF BND TLV and its sub-TLVs is identical to the 403 TLV format used by the Traffic Engineering Extensions to OSPF 404 [RFC3630]. That is, the TLV is composed of 2 octets for the type, 2 405 octets specifying the TLV length, and a value field. The Length 406 field defines the length of the value portion in octets. 408 The OSPF BND TLV has the following format: 410 1 2 3 411 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 1 412 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 413 | Type | Length | 414 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 415 | | 416 // sub-TLVs // 417 | | 418 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 420 Type: To be assigned by IANA (suggested value 8) 421 Length: Variable 422 Value: This comprises of following sub-TLVs 424 Two sub-TLVs are defined: 425 Sub-TLV type Length Name 426 1 variable BN-ADDRESS sub-TLV 427 2 4 BN-DOMAIN sub-TLV 429 The BN-ADDRESS and BN-DOMAIN sub-TLVs MUST always be present within 430 the BND TLV. 432 Malformed BND TLVs or sub-TLVs not explicitly described in this 433 document MUST cause the LSA to be treated as malformed according to 434 the normal procedures of OSPF. 436 Any unrecognized sub-TLV MUST be silently ignored. 438 The BND TLV is carried within an OSPF Router Information LSA defined 439 in [RFC4970]. 441 The following sub-sections describe the sub-TLVs which are carried 442 within the BND TLV. 444 7.1. BN-ADDRESS Sub-TLV 446 The BN-ADDRESS sub-TLV specifies an IP address that can be used to 447 reach the BN. It is RECOMMENDED to make use of an address that is 448 always reachable, provided that the BN is alive and reachable. 450 The BN-ADDRESS sub-TLV is mandatory; it MUST be present within the 451 BND TLV. It MAY appear twice, when the BN has both an IPv4 and IPv6 452 address. It MUST NOT appear more than once for the same address 453 type. If it appears more than once for the same address type, only 454 the first occurrence is processed and any others MUST be ignored. 456 The format of the BN-ADDRESS sub-TLV is as follows: 458 1 2 3 459 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 1 460 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 461 | Type = 1 | Length | 462 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 463 | address-type | Reserved | 464 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 465 | | 466 // BN IP Address // 467 | | 468 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 470 BN-ADDRESS sub-TLV format 472 Type: 1 473 Length: 8 (IPv4) or 20 (IPv6) 475 Address-type: 476 1 IPv4 477 2 IPv6 479 Reserved: SHOULD be set to zero on transmission and MUST be ignored 480 on receipt. 482 BN IP Address: The IP address to be used to reach the BN. 484 7.2. BN-DOMAIN Sub-TLV 486 The BN-DOMAIN sub-TLV specifies a BN-Domain (area or AS) where the BN 487 has topology connectivity. 489 The BN-DOMAIN sub-TLV is mandatory; it MUST be present within the BND 490 TLV. 492 A BND TLV MUST include two or more BN-DOMAIN sub-TLVs as the BN has 493 connectivity into multiple BN-Domains. 495 The BN-DOMAIN sub-TLV has the following format: 497 1 2 3 498 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 1 499 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 500 | Type = 2 | Length | 501 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 502 | Domain-type | Reserved | 503 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 504 | Domain ID | 505 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 507 BN-DOMAIN sub-TLV format 509 Type: 2 510 Length: 8 512 Two domain-type values are defined: 513 1 OSPF Area ID 514 2 AS Number 516 Domain ID: With the domain-type set to 1, this indicates the 32-bit 517 Area ID of an area where the BN (ABR) has connectivity. With domain- 518 type set to 2, this indicates an AS number of an AS where the BN 519 (ASBR) has connectivity. When the AS number is coded in two octets, 520 the AS Number field MUST have its first two octets set to 0. 522 8. Elements of Procedure 524 The BND TLV is advertised within OSPFv2 Router Information LSAs 525 (Opaque type of 4 and Opaque ID of 0) or OSPFv3 Router Information 526 LSAs (function code of 12), which are defined in [RFC4970]. As such, 527 elements of procedure are inherited from those defined in [RFC4970]. 529 In OSPFv2, the flooding scope is controlled by the opaque LSA type(as 530 defined in [RFC5250]) and in OSPFv3, by the S1/S2 bits (as defined in 531 [RFC5340]). If the flooding scope is area local, then the BND TLV 532 MUST be carried within an OSPFv2 type 10 router information LSA or an 533 OSPFV3 Router Information LSA with the S1 bit set and the S2 bit 534 clear. If the flooding scope is the entire IGP domain, then the BND 535 TLV MUST be carried within an OSPFv2 type 11 Router Information LSA 536 or OSPFv3 Router Information LSA with the S1 bit clear and the S2 bit 537 set. 539 When the BN function is deactivated, the OSPF speaker MUST originate 540 a new Router Information LSA that no longer includes the 541 corresponding BND TLV, provided there are other TLVs in the LSA. If 542 there are no other TLVs in the LSA, it MUST either send an empty 543 Router Information LSA or purge it by prematurely aging it. 545 The BN address (i.e., the address indicated within the BN-ADDRESS 546 sub-TLV) SHOULD be reachable via some prefixes advertised by OSPF. 548 The BND TLV information regarding a specific BN is only considered 549 current and useable when the router advertising this information is 550 itself reachable via OSPF calculated paths in the same area of the 551 LSA in which the BND TLV appears. 553 A change in the state of a BN (activate, deactivate, domain change) 554 MUST result in a corresponding change in the BND TLV information 555 advertised by an OSPF router (inserted, removed, updated)in its LSA. 556 The way BNs determine the information they advertise, and how that 557 information is made available to OSPF, is out of the scope of this 558 document. Some information may be configured and other information 559 may be automatically determined by the OSPF. 561 A change in information in the BND TLV MUST NOT trigger any SPF 562 computation at a receiving router. 564 9. Backward Compatibility 566 The BND TLV defined in this document does not introduce any 567 interoperability issues. 569 A router not supporting the BND TLV will just silently ignore the TLV 570 as specified in [RFC4970]. 572 10. Impact on Network 574 The routers acting as BNs will originate Opaque LSA with BND Tlv; As 575 there are only few BNs exist in the network, the performance impact 576 in flooding is very less. 578 11. IANA Considerations 580 11.1. OSPF TLV 582 IANA has defined a registry for TLVs carried in the Router 583 Information LSA defined in [RFC4970]. A number of IANA 584 considerations have been highlighted in previous sections of this 585 document. IANA is requested to make the following allocations. 587 Value TLV Name Reference 588 ----- -------- ---------- 589 To be BND (this document) 590 assigned 591 by IANA 593 12. Security Considerations 595 This document defines OSPF extensions for BN discovery within an 596 administrative domain. Hence the security of the BN discovery relies 597 on the security of OSPF. 599 Mechanisms defined to ensure authenticity and integrity of OSPF LSAs 600 [RFC2154], and their TLVs, can be used to secure the BN Discovery 601 information as well. 603 OSPF provides no encryption mechanism for protecting the privacy of 604 LSAs and, in particular, the privacy of the BN discovery information. 606 13. Manageability Considerations 608 TBD 610 14. Acknowledgments 612 We would like to thank Quintin Zhao, Daniel King, Adrian Ferral, 613 Suresh babu, Pradeep Shastry, Saravana Kumar, Srinivasan and 614 Venugopal Reddy for their useful comments and suggestions. 616 15. References 618 15.1. Normative References 620 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 621 Requirement Levels", BCP 14, RFC 2119, March 1997. 623 [RFC2154] Murphy, S., Badger, M., and B. Wellington, "OSPF with 624 Digital Signatures", RFC 2154, June 1997. 626 [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. 628 [RFC4970] Lindem, A., Shen, N., Vasseur, JP., Aggarwal, R., and S. 629 Shaffer, "Extensions to OSPF for Advertising Optional 630 Router Capabilities", RFC 4970, July 2007. 632 [RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The 633 OSPF Opaque LSA Option", RFC 5250, July 2008. 635 [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF 636 for IPv6", RFC 5340, July 2008. 638 15.2. Informative References 640 [RFC3509] Zinin, A., Lindem, A., and D. Yeung, "Alternative 641 Implementations of OSPF Area Border Routers", RFC 3509, 642 April 2003. 644 [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering 645 (TE) Extensions to OSPF Version 2", RFC 3630, September 646 2003. 648 [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation 649 Element (PCE)-Based Architecture", RFC 4655, August 2006. 651 [RFC5392] Chen, M., Zhang, R., and X. Duan, "OSPF Extensions in 652 Support of Inter-Autonomous System (AS) MPLS and GMPLS 653 Traffic Engineering", RFC 5392, January 2009. 655 [RFC5441] Vasseur, JP., Zhang, R., Bitar, N., and JL. Le Roux, "A 656 Backward-Recursive PCE-Based Computation (BRPC) Procedure 657 to Compute Shortest Constrained Inter-Domain Traffic 658 Engineering Label Switched Paths", RFC 5441, April 2009. 660 [RFC6805] King, D. and A. Farrel, "The Application of the Path 661 Computation Element Architecture to the Determination of a 662 Sequence of Domains in MPLS and GMPLS", RFC 6805, November 663 2012. 665 [DOMAIN-SEQ] 666 Dhody, D., Palle, U., and R. Casellas, "Standard 667 Representation Of Domain Sequence (draft-ietf-pce-pcep- 668 domain-sequence-05)", July 2014. 670 Authors' Addresses 672 Dhruv Dhody 673 Huawei Technologies India Pvt Ltd 674 Leela Palace 675 Bangalore, Karnataka 560008 676 India 678 EMail: dhruv.ietf@gmail.com 679 Udayasree Palle 680 Huawei Technologies India Pvt Ltd 681 Leela Palace 682 Bangalore, Karnataka 560008 683 India 685 EMail: udayasree.palle@huawei.com