idnits 2.17.00 (12 Aug 2021) /tmp/idnits55987/draft-ietf-ospf-te-link-attr-reuse-09.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 (September 19, 2019) is 975 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: draft-ietf-isis-te-app has been published as RFC 8919 == Outdated reference: A later version (-20) exists of draft-ietf-lsr-flex-algo-04 Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 LSR Working Group P. Psenak, Ed. 3 Internet-Draft L. Ginsberg 4 Intended status: Standards Track Cisco Systems 5 Expires: March 22, 2020 W. Henderickx 6 Nokia 7 J. Tantsura 8 Apstra 9 J. Drake 10 Juniper Networks 11 September 19, 2019 13 OSPF Link Traffic Engineering Attribute Reuse 14 draft-ietf-ospf-te-link-attr-reuse-09.txt 16 Abstract 18 Various link attributes have been defined in OSPF in the context of 19 the MPLS Traffic Engineering (TE) and GMPLS. Many of these link 20 attributes can be used for applications other than MPLS TE or GMPLS. 21 This document defines how to distribute such attributes in OSPFv2 and 22 OSPFv3 for applications other than MPLS TE or GMPLS. 24 Status of This Memo 26 This Internet-Draft is submitted in full conformance with the 27 provisions of BCP 78 and BCP 79. 29 Internet-Drafts are working documents of the Internet Engineering 30 Task Force (IETF). Note that other groups may also distribute 31 working documents as Internet-Drafts. The list of current Internet- 32 Drafts is at https://datatracker.ietf.org/drafts/current/. 34 Internet-Drafts are draft documents valid for a maximum of six months 35 and may be updated, replaced, or obsoleted by other documents at any 36 time. It is inappropriate to use Internet-Drafts as reference 37 material or to cite them other than as "work in progress." 39 This Internet-Draft will expire on March 22, 2020. 41 Copyright Notice 43 Copyright (c) 2019 IETF Trust and the persons identified as the 44 document authors. All rights reserved. 46 This document is subject to BCP 78 and the IETF Trust's Legal 47 Provisions Relating to IETF Documents 48 (https://trustee.ietf.org/license-info) in effect on the date of 49 publication of this document. Please review these documents 50 carefully, as they describe your rights and restrictions with respect 51 to this document. Code Components extracted from this document must 52 include Simplified BSD License text as described in Section 4.e of 53 the Trust Legal Provisions and are provided without warranty as 54 described in the Simplified BSD License. 56 Table of Contents 58 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 59 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3 60 2. Advertisement of Link Attributes . . . . . . . . . . . . . . 3 61 2.1. OSPFv2 Extended Link Opaque LSA and OSPFv3 E-Router-LSA . 3 62 3. Advertisement of Application Specific Values . . . . . . . . 4 63 4. Reused TE link attributes . . . . . . . . . . . . . . . . . . 7 64 4.1. Shared Risk Link Group (SRLG) . . . . . . . . . . . . . . 7 65 4.2. Extended Metrics . . . . . . . . . . . . . . . . . . . . 8 66 4.3. Administrative Group . . . . . . . . . . . . . . . . . . 9 67 4.4. TE Metric . . . . . . . . . . . . . . . . . . . . . . . . 9 68 5. Maximum Link Bandwidth . . . . . . . . . . . . . . . . . . . 9 69 6. Local Interface IPv6 Address Sub-TLV . . . . . . . . . . . . 10 70 7. Remote Interface IPv6 Address Sub-TLV . . . . . . . . . . . . 10 71 8. Deployment Considerations . . . . . . . . . . . . . . . . . . 10 72 9. Attribute Advertisements and Enablement . . . . . . . . . . . 10 73 10. Backward Compatibility . . . . . . . . . . . . . . . . . . . 11 74 11. Security Considerations . . . . . . . . . . . . . . . . . . . 12 75 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 76 12.1. OSPFv2 . . . . . . . . . . . . . . . . . . . . . . . . . 12 77 12.2. OSPFv3 . . . . . . . . . . . . . . . . . . . . . . . . . 13 78 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14 79 14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14 80 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 81 15.1. Normative References . . . . . . . . . . . . . . . . . . 15 82 15.2. Informative References . . . . . . . . . . . . . . . . . 15 83 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 85 1. Introduction 87 Various link attributes have been defined in OSPFv2 [RFC2328] and 88 OSPFv3 [RFC5340] in the context of the MPLS TE and GMPLS. All these 89 attributes are distributed by OSPFv2 as sub-TLVs of the Link-TLV 90 advertised in the OSPFv2 TE Opaque LSA [RFC3630]. In OSPFv3, they 91 are distributed as sub-TLVs of the Link-TLV advertised in the OSPFv3 92 Intra-Area-TE-LSA as defined in [RFC5329]. 94 Many of these link attributes are useful outside of traditional MPLS 95 Traffic Engineering or GMPLS. This brings its own set of problems, 96 in particular how to distribute these link attributes in OSPFv2 and 97 OSPFv3 when MPLS TE and GMPLS are not deployed or are deployed in 98 parallel with other applications that use these link attributes. 100 [RFC7855] discusses use cases/requirements for Segment Routing (SR). 101 Included among these use cases is Segment Routing Traffic Engineering 102 (SRTE). If both RSVP-TE and SRTE are deployed in a network, link 103 attribute advertisements can be used by one or both of these 104 applications. As there is no requirement for the link attributes 105 advertised on a given link used by SRTE to be identical to the link 106 attributes advertised on that same link used by RSVP-TE, there is a 107 clear requirement to indicate independently which link attribute 108 advertisements are to be used by each application. 110 As the number of applications which may wish to utilize link 111 attributes may grow in the future, an additional requirement is that 112 the extensions defined allow the association of additional 113 applications to link attributes without altering the format of the 114 advertisements or introducing new backwards compatibility issues. 116 Finally, there may still be many cases where a single attribute value 117 can be shared among multiple applications, so the solution should 118 minimize advertising duplicate link/attribute when possible. 120 1.1. Requirements notation 122 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 123 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 124 document are to be interpreted as described in [RFC2119]. 126 2. Advertisement of Link Attributes 128 This section outlines the solution for advertising link attributes 129 originally defined for MPLS TE or GMPLS when they are used for other 130 applications. 132 2.1. OSPFv2 Extended Link Opaque LSA and OSPFv3 E-Router-LSA 134 Extended Link Opaque LSAs as defined in [RFC7684] for OSPFv2 and 135 Extended Router-LSAs [RFC8362] for OSPFv3 are used to advertise link 136 attributes that are used by applications other then MPLS TE or GMPLS. 137 These LSAs were defined as a generic containers for distribution of 138 the extended link attributes. There are several advantages in using 139 them: 141 1. Advertisement of the link attributes does not make the link part 142 of the TE topology. It avoids any conflicts and is fully 143 compatible with [RFC3630] and [RFC5329]. 145 2. The OSPFv2 TE Opaque LSA and OSPFv3 Intra-Area-TE-LSA remains 146 truly opaque to OSPFv2 and OSPFv3 as originally defined in 147 [RFC3630] and [RFC5329] respectively. Their contents are not 148 inspected by OSPF, that acts as a pure transport. 150 3. There is clear distinction between link attributes used by TE and 151 link attributes used by other OSPFv2 or OSPFv3 applications. 153 4. All link attributes that are used by other applications are 154 advertised in a single LSA, the Extended Link Opaque LSA in 155 OSPFv2 or the OSPFv3 E-Router-LSA [RFC8362] in OSPFv3. 157 The disadvantage of this approach is that in rare cases, the same 158 link attribute is advertised in both the TE Opaque and Extended Link 159 Attribute LSAs in OSPFv2 or the Intra-Area-TE-LSA and E-Router-LSA in 160 OSPFv3. Additionally, there will be additional standardization 161 effort. However, this could also be viewed as an advantage as the 162 non-TE use cases for the TE link attributes are documented and 163 validated by the LSR working group. 165 Extended Link Opaque LSA [RFC7684] and E-Router-LSA [RFC8362] are 166 used to advertise any link attributes used for non-TE applications in 167 OSPFv2 or OSPFv3 respectively, including those that have been 168 originally defined for TE applications. 170 TE link attributes used for RSVP-TE/GMPLS continue to use OSPFv2 TE 171 Opaque LSA [RFC3630] and OSPFv3 Intra-Area-TE-LSA [RFC5329]. 173 The format of the link attribute TLVs that have been defined for TE 174 applications will be kept unchanged even when they are used for non- 175 TE applications. Unique code points will be allocated for these TE 176 link attribute TLVs from the OSPFv2 Extended Link TLV Sub-TLV 177 Registry [RFC7684] and from the OSPFv3 Extended LSA Sub-TLV Registry 178 [RFC8362]. For each reused TLV, the code point will be defined in an 179 IETF document along with the expected use-case(s). 181 3. Advertisement of Application Specific Values 183 To allow advertisement of the application specific values of the link 184 attribute, a new Application Specific Link Attributes (ASLA) sub-TLV 185 is defined. The ASLA sub-TLV is a sub-TLV of the OSPFv2 Extended 186 Link TLV [RFC7471] and OSPFv3 Router-Link TLV [RFC8362]. 188 The ASLA sub-TLV is an optional sub-TLV and can appear multiple times 189 in the OSPFv2 Extended Link TLV and OSPFv3 Router-Link TLV. It has 190 the following format: 192 0 1 2 3 193 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 1 194 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 195 | Type | Length | 196 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 197 | SABML | UDABML | Reserved | 198 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 199 | Standard Application Bit-Mask | 200 +- -+ 201 | ... | 202 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 203 | User Defined Application Bit-Mask | 204 +- -+ 205 | ... | 206 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 207 | Link Attribute sub-sub-TLVs | 208 +- -+ 209 | ... | 211 where: 213 Type: 10 (OSPFv2), 11 (OSPFv3) 215 Length: variable 217 SABML: Standard Application Bit-Mask Length. It MUST be a 218 multiple of 4 bytes. If the Standard Application Bit-Mask is not 219 present, the Standard Application Bit-Mask Length MUST be set to 220 0. 222 UDABML: User Defined Application Bit-Mask Length. It MUST be a 223 multiple of 4 bytes. If the User Defined Application Bit-Mask is 224 not present, the User Defined Application Bit-Mask Length MUST be 225 set to 0. 227 Standard Application Bit-Mask: Optional set of bits, where each 228 bit represents a single standard application. Bits are defined in 229 [I-D.ietf-isis-te-app], which also request a new IANA "Link 230 Attribute Applications" registry under "Interior Gateway Protocol 231 (IGP) Parameters" for them. The bits are repeated here for 232 informational purpose: 234 Bit-0: RSVP TE 236 Bit-1: Segment Routing TE 238 Bit-2: Loop Free Alternate (LFA). Includes all LFA types 239 Bit-3: Flexible Algorithm 241 User Defined Application Bit-Mask: Optional set of bits, where 242 each bit represents a single user defined application. 244 Standard Application Bits are defined/sent starting with Bit 0. 245 Additional bit definitions that are defined in the future SHOULD be 246 assigned in ascending bit order so as to minimize the number of 247 octets that will need to be transmitted. 249 User Defined Application bits have no relationship to Standard 250 Application bits and are NOT managed by IANA or any other standards 251 body. It is recommended that bits are used starting with Bit 0 so as 252 to minimize the number of octets required to advertise all of them. 254 Undefined bits in both Bit-Masks MUST be transmitted as 0 and MUST be 255 ignored on receipt. Bits that are NOT transmitted MUST be treated as 256 if they are set to 0 on receipt. 258 If the link attribute advertisement is limited to be used by a 259 specific set of applications, corresponding Bit-Masks MUST be present 260 and application specific bit(s) MUST be set for all applications that 261 use the link attributes advertised in the ASLA sub-TLV. 263 Application Bit-Masks apply to all link attributes that support 264 application specific values and are advertised in the ASLA sub-TLV. 266 The advantage of not making the Application Bit-Masks part of the 267 attribute advertisement itself is that we can keep the format of the 268 link attributes that have been defined previously and reuse the same 269 format when advertising them in the ASLA sub-TLV. 271 When neither the Standard Application Bits nor the User Defined 272 Application bits are set (i.e., both SABML and UDABML are 0) in the 273 ASLA sub-TLV, then the link attributes included in it MUST be 274 considered as being applicable to all applications. 276 If, however, another advertisement of the same link attribute 277 includes any Application Bit-Mask in the ASLA sub-TLV, applications 278 that are listed in the Application Bit-Masks of such ASLA sub-TLV 279 SHOULD use the attribute advertisement which has the application 280 specific bit set in the Application Bit-Masks. 282 If the same application is listed in the Application Bit-Masks of 283 more then one ASLA sub-TLV, the application SHOULD use the first 284 advertisement and ignore any subsequent advertisements of the same 285 attribute. This situation SHOULD be logged as an error. 287 This document defines the initial set of link attributes that MUST 288 use ASLA sub-TLV if advertised in the OSPFv2 Extended Link TLV or in 289 the OSPFv3 Router-Link TLV. If the ASLA sub-TLV includes any link 290 attribute(s) NOT listed below, they MUST be ignored. Documents which 291 define new link attributes MUST state whether the new attributes 292 support application specific values and as such MUST be advertised in 293 an ASLA sub-TLV. The link attributes that MUST be advertised in ASLA 294 sub-TLVs are: 296 - Shared Risk Link Group 298 - Unidirectional Link Delay 300 - Min/Max Unidirectional Link Delay 302 - Unidirectional Delay Variation 304 - Unidirectional Link Loss 306 - Unidirectional Residual Bandwidth 308 - Unidirectional Available Bandwidth 310 - Unidirectional Utilized Bandwidth 312 - Administrative Group 314 - Extended Administrative Group 316 - TE Metric 318 4. Reused TE link attributes 320 This section defines the use case and code points from the OSPFv2 321 Extended Link TLV Sub-TLV Registry and OSPFv3 Extended LSA Sub-TLV 322 Registry for some of the link attributes that have been originally 323 defined for TE or GMPLS. 325 4.1. Shared Risk Link Group (SRLG) 327 The SRLG of a link can be used in OSPF calculated IPFRR [RFC5714] to 328 compute a backup path that does not share any SRLG group with the 329 protected link. 331 To advertise the SRLG of the link in the OSPFv2 Extended Link TLV, 332 the same format for the sub-TLV defined in section 1.3 of [RFC4203] 333 is used and TLV type 11 is used. Similarly, for OSPFv3 to advertise 334 the SRLG in the OSPFv3 Router-Link TLV, TLV type 12 is used. 336 4.2. Extended Metrics 338 [RFC3630] defines several link bandwidth types. [RFC7471] defines 339 extended link metrics that are based on link bandwidth, delay and 340 loss characteristics. All these can be used to compute primary and 341 backup paths within an OSPF area to satisfy requirements for 342 bandwidth, delay (nominal or worst case) or loss. 344 To advertise extended link metrics in the OSPFv2 Extended Link TLV, 345 the same format for the sub-TLVs defined in [RFC7471] is used with 346 the following TLV types: 348 12 - Unidirectional Link Delay 350 13 - Min/Max Unidirectional Link Delay 352 14 - Unidirectional Delay Variation 354 15 - Unidirectional Link Loss 356 16 - Unidirectional Residual Bandwidth 358 17 - Unidirectional Available Bandwidth 360 18 - Unidirectional Utilized Bandwidth 362 To advertise extended link metrics in the OSPFv3 Extended LSA Router- 363 Link TLV, the same format for the sub-TLVs defined in [RFC7471] is 364 used with the following TLV types: 366 13 - Unidirectional Link Delay 368 14 - Min/Max Unidirectional Link Delay 370 15 - Unidirectional Delay Variation 372 16 - Unidirectional Link Loss 374 17 - Unidirectional Residual Bandwidth 376 18 - Unidirectional Available Bandwidth 378 19 - Unidirectional Utilized Bandwidth 380 4.3. Administrative Group 382 [RFC3630] and [RFC7308] define the Administrative Group and Extended 383 Administrative Group sub-TLVs respectively. 385 One use case where advertisement of the Extended Administrative 386 Group(s) for a link is required is described in 387 [I-D.ietf-lsr-flex-algo]. 389 To advertise the Administrative Group and Extended Administrative 390 Group in the OSPFv2 Extended Link TLV, the same format for the sub- 391 TLVs defined in [RFC3630] and [RFC7308] is used with the following 392 TLV types: 394 19 - Administrative Group 396 20 - Extended Administrative Group 398 To advertise Administrative Group and Extended Administrative Group 399 in the OSPFv3 Router-Link TLV, the same format for the sub-TLVs 400 defined in [RFC3630] and [RFC7308] is used with the following TLV 401 types: 403 20 - Administrative Group 405 21 - Extended Administrative Group 407 4.4. TE Metric 409 [RFC3630] defines TE Metric. 411 To advertise the TE Metric in the OSPFv2 Extended Link TLV, the same 412 format for the sub-TLV defined in section 2.5.5 of [RFC3630] is used 413 and TLV type 22 is used. Similarly, for OSPFv3 to advertise the TE 414 Metric in the OSPFv3 Router-Link TLV, TLV type 22 is used. 416 5. Maximum Link Bandwidth 418 Maximum link bandwidth is an application independent attribute of the 419 link that is defined in [RFC3630]. Because it is an application 420 independent attribute, it MUST NOT be advertised in ASLA sub-TLV. 421 Instead, it MAY be advertised as a sub-TLV of the Extended Link 422 Opaque LSA Extended Link TLV in OSPFv2 [RFC7684] or sub-TLV of OSPFv3 423 E-Router-LSA Router-Link TLV in OSPFv3 [RFC8362]. 425 To advertise the Maximum link bandwidth in the OSPFv2 Extended Link 426 TLV, the same format for sub-TLV defined in [RFC3630] is used with 427 TLV type 23. 429 To advertise the Maximum link bandwidth in the OSPFv3 Router-Link 430 TLV, the same format for sub-TLV defined in [RFC3630] is used with 431 TLV type 23. 433 6. Local Interface IPv6 Address Sub-TLV 435 The Local Interface IPv6 Address Sub-TLV is an application 436 independent attribute of the link that is defined in [RFC5329]. 437 Because it is an application independent attribute, it MUST NOT be 438 advertised in the ASLA sub-TLV. Instead, it MAY be advertised as a 439 sub-TLV of the OSPFv3 E-Router-LSA Router-Link TLV [RFC8362]. 441 To advertise the Local Interface IPv6 Address Sub-TLV in the OSPFv3 442 Router-Link TLV, the same format for sub-TLV defined in [RFC5329] is 443 used with TLV type 24. 445 7. Remote Interface IPv6 Address Sub-TLV 447 The Remote Interface IPv6 Address Sub-TLV is an application 448 independent attribute of the link that is defined in [RFC5329]. 449 Because it is an application independent attribute, it MUST NOT be 450 advertised in the ASLA sub-TLV. Instead, it MAY be advertised as a 451 sub-TLV of the OSPFv3 E-Router-LSA Router-Link TLV [RFC8362]. 453 To advertise the Remote Interface IPv6 Address Sub-TLV in the OSPFv3 454 Router-Link TLV, the same format for sub-TLV defined in [RFC5329] is 455 used with TLV type 25. 457 8. Deployment Considerations 459 If link attributes are advertised associated with zero length 460 application bit masks for both standard applications and user defined 461 applications, then that set of link attributes MAY be used by any 462 application. If support for a new application is introduced on any 463 node in a network in the presence of such advertisements, these 464 advertisements MAY be used by the new application. If this is not 465 what is intended, then existing advertisements MUST be readvertised 466 with an explicit set of applications specified before a new 467 application is introduced. 469 9. Attribute Advertisements and Enablement 471 This document defines extensions to support the advertisement of 472 application specific link attributes. 474 Whether the presence of link attribute advertisements for a given 475 application indicates that the application is enabled on that link 476 depends upon the application. Similarly, whether the absence of link 477 attribute advertisements indicates that the application is not 478 enabled depends upon the application. 480 In the case of RSVP-TE, the advertisement of application specific 481 link attributes implies that RSVP is enabled on that link. 483 In the case of SRTE, advertisement of application specific link 484 attributes does NOT indicate enablement of SRTE. The advertisements 485 are only used to support constraints which may be applied when 486 specifying an explicit path. SRTE is implicitly enabled on all links 487 which are part of the Segment Routing enabled topology independent of 488 the existence of link attribute advertisements. 490 In the case of LFA, advertisement of application specific link 491 attributes does NOT indicate enablement of LFA on that link. 492 Enablement is controlled by local configuration. 494 In the case of Flexible Algorithm, advertisement of application 495 specific link attributes does NOT indicate enablement of Flexible 496 Algorithm on that link. Rather the attributes are used to determine 497 what links are included/excluded in the algorithm specific 498 constrained SPF. This is fully specified in 499 [I-D.ietf-lsr-flex-algo]. 501 If, in the future, additional standard applications are defined to 502 use this mechanism, the specification defining this use MUST define 503 the relationship between application specific link attribute 504 advertisements and enablement for that application. 506 This document allows the advertisement of application specific link 507 attributes with no application identifiers i.e., both the Standard 508 Application Bit Mask and the User Defined Application Bit Mask are 509 not present (See Section 3). This supports the use of the link 510 attribute by any application. In the presence of an application 511 where the advertisement of link attribute advertisements is used to 512 infer the enablement of an application on that link (e.g., RSVP-TE), 513 the absence of the application identifier leaves ambiguous whether 514 that application is enabled on such a link. This needs to be 515 considered when making use of the "any application" encoding. 517 10. Backward Compatibility 519 Link attributes may be concurrently advertised in both the TE Opaque 520 LSA and the Extended Link Opaque LSA in OSPFv2 and the OSPFv3 Intra- 521 Area-TE-LSA and OSPFv3 Extended LSA Router-Link TLV in OSPFv3. 523 In fact, there is at least one OSPF implementation that utilizes the 524 link attributes advertised in TE Opaque LSAs [RFC3630] for Non-RSVP 525 TE applications. For example, this implementation of LFA and remote 526 LFA utilizes links attributes such as Shared Risk Link Groups (SRLG) 527 [RFC4203] and Admin Group [[RFC3630] advertised in TE Opaque LSAs. 528 These applications are described in [RFC5286], [RFC7490], [RFC7916] 529 and [RFC8102]. 531 When an OSPF routing domain includes routers using link attributes 532 from the OSPFv2 TE Opaque LSAs or the OSPFv3 Intra-Area-TE-LSA for 533 Non-RSVP TE applications such as LFA, OSPF routers in that domain 534 SHOULD continue to advertise such OSPFv2 TE Opaque LSAs or the OSPFv3 535 Intra-Area-TE-LSA. If there are also OSPF routers using the link 536 attributes described herein for any other application, OSPF routers 537 in the routing domain will also need to advertise these attributes in 538 OSPFv2 Extended Link Attributes LSAs or OSPFv3 E-Router-LSA. In such 539 a deployment, the advertised attributes SHOULD be the same and Non- 540 RSVP application access to link attributes is a matter of local 541 policy. 543 11. Security Considerations 545 Existing security extensions as described in [RFC2328], [RFC5340] and 546 [RFC8362] apply to extensions defined in this document. While OSPF 547 is under a single administrative domain, there can be deployments 548 where potential attackers have access to one or more networks in the 549 OSPF routing domain. In these deployments, stronger authentication 550 mechanisms such as those specified in [RFC5709], [RFC7474], [RFC4552] 551 or [RFC7166] SHOULD be used. 553 Implementations MUST assure that malformed TLV and Sub-TLV defined in 554 this document are detected and do not provide a vulnerability for 555 attackers to crash the OSPF router or routing process. Reception of 556 a malformed TLV or Sub-TLV SHOULD be counted and/or logged for 557 further analysis. Logging of malformed TLVs and Sub-TLVs SHOULD be 558 rate-limited to prevent a Denial of Service (DoS) attack (distributed 559 or otherwise) from overloading the OSPF control plane. 561 12. IANA Considerations 563 12.1. OSPFv2 565 OSPFv2 Extended Link TLV Sub-TLVs registry [RFC7684] defines sub-TLVs 566 at any level of nesting for OSPFv2 Extended Link TLVs. This 567 specification updates OSPFv2 Extended Link TLV sub-TLVs registry with 568 the following TLV types: 570 10 - Application Specific Link Attributes 572 11 - Shared Risk Link Group 573 12 - Unidirectional Link Delay 575 13 - Min/Max Unidirectional Link Delay 577 14 - Unidirectional Delay Variation 579 15 - Unidirectional Link Loss 581 16 - Unidirectional Residual Bandwidth 583 17 - Unidirectional Available Bandwidth 585 18 - Unidirectional Utilized Bandwidth 587 19 - Administrative Group 589 20 - Extended Administrative Group 591 22 - TE Metric 593 23 - Maximum Link Bandwidth 595 12.2. OSPFv3 597 OSPFv3 Extended LSA Sub-TLV Registry [RFC8362] defines sub-TLVs at 598 any level of nesting for OSPFv3 Extended LSAs. This specification 599 updates OSPFv3 Extended LSA Sub-TLV Registry with the following TLV 600 types: 602 11 - Application Specific Link Attributes 604 12 - Shared Risk Link Group 606 13 - Unidirectional Link Delay 608 14 - Min/Max Unidirectional Link Delay 610 15 - Unidirectional Delay Variation 612 16 - Unidirectional Link Loss 614 16 - Unidirectional Residual Bandwidth 616 18 - Unidirectional Available Bandwidth 618 19 - Unidirectional Utilized Bandwidth 620 20 - Administrative Group 621 21 - Extended Administrative Group 623 22 - TE Metric 625 23 - Maximum Link Bandwidth 627 24 - Local Interface IPv6 Address Sub-TLV 629 25 - Remote Interface IPv6 Address Sub-TLV 631 13. Contributors 633 The following people contributed to the content of this document and 634 should be considered as co-authors: 636 Acee Lindem 637 Cisco Systems 638 301 Midenhall Way 639 Cary, NC 27513 640 USA 642 Email: acee@cisco.com 644 Ketan Talaulikar 645 Cisco Systems, Inc. 646 India 648 Email: ketant@cisco.com 650 Hannes Gredler 651 RtBrick Inc. 652 Austria 654 Email: hannes@rtbrick.com 656 14. Acknowledgments 658 Thanks to Chris Bowers for his review and comments. 660 15. References 661 15.1. Normative References 663 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 664 Requirement Levels", BCP 14, RFC 2119, 665 DOI 10.17487/RFC2119, March 1997, 666 . 668 [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering 669 (TE) Extensions to OSPF Version 2", RFC 3630, 670 DOI 10.17487/RFC3630, September 2003, 671 . 673 [RFC5329] Ishiguro, K., Manral, V., Davey, A., and A. Lindem, Ed., 674 "Traffic Engineering Extensions to OSPF Version 3", 675 RFC 5329, DOI 10.17487/RFC5329, September 2008, 676 . 678 [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF 679 for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008, 680 . 682 [RFC7308] Osborne, E., "Extended Administrative Groups in MPLS 683 Traffic Engineering (MPLS-TE)", RFC 7308, 684 DOI 10.17487/RFC7308, July 2014, 685 . 687 [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., 688 Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute 689 Advertisement", RFC 7684, DOI 10.17487/RFC7684, November 690 2015, . 692 [RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and 693 F. Baker, "OSPFv3 Link State Advertisement (LSA) 694 Extensibility", RFC 8362, DOI 10.17487/RFC8362, April 695 2018, . 697 15.2. Informative References 699 [I-D.ietf-isis-te-app] 700 Ginsberg, L., Psenak, P., Previdi, S., Henderickx, W., and 701 J. Drake, "IS-IS TE Attributes per application", draft- 702 ietf-isis-te-app-06 (work in progress), April 2019. 704 [I-D.ietf-lsr-flex-algo] 705 Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and 706 A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex- 707 algo-04 (work in progress), September 2019. 709 [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, 710 DOI 10.17487/RFC2328, April 1998, 711 . 713 [RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in 714 Support of Generalized Multi-Protocol Label Switching 715 (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005, 716 . 718 [RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality 719 for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006, 720 . 722 [RFC5286] Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for 723 IP Fast Reroute: Loop-Free Alternates", RFC 5286, 724 DOI 10.17487/RFC5286, September 2008, 725 . 727 [RFC5709] Bhatia, M., Manral, V., Fanto, M., White, R., Barnes, M., 728 Li, T., and R. Atkinson, "OSPFv2 HMAC-SHA Cryptographic 729 Authentication", RFC 5709, DOI 10.17487/RFC5709, October 730 2009, . 732 [RFC5714] Shand, M. and S. Bryant, "IP Fast Reroute Framework", 733 RFC 5714, DOI 10.17487/RFC5714, January 2010, 734 . 736 [RFC7166] Bhatia, M., Manral, V., and A. Lindem, "Supporting 737 Authentication Trailer for OSPFv3", RFC 7166, 738 DOI 10.17487/RFC7166, March 2014, 739 . 741 [RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S. 742 Previdi, "OSPF Traffic Engineering (TE) Metric 743 Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015, 744 . 746 [RFC7474] Bhatia, M., Hartman, S., Zhang, D., and A. Lindem, Ed., 747 "Security Extension for OSPFv2 When Using Manual Key 748 Management", RFC 7474, DOI 10.17487/RFC7474, April 2015, 749 . 751 [RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N. 752 So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)", 753 RFC 7490, DOI 10.17487/RFC7490, April 2015, 754 . 756 [RFC7855] Previdi, S., Ed., Filsfils, C., Ed., Decraene, B., 757 Litkowski, S., Horneffer, M., and R. Shakir, "Source 758 Packet Routing in Networking (SPRING) Problem Statement 759 and Requirements", RFC 7855, DOI 10.17487/RFC7855, May 760 2016, . 762 [RFC7916] Litkowski, S., Ed., Decraene, B., Filsfils, C., Raza, K., 763 Horneffer, M., and P. Sarkar, "Operational Management of 764 Loop-Free Alternates", RFC 7916, DOI 10.17487/RFC7916, 765 July 2016, . 767 [RFC8102] Sarkar, P., Ed., Hegde, S., Bowers, C., Gredler, H., and 768 S. Litkowski, "Remote-LFA Node Protection and 769 Manageability", RFC 8102, DOI 10.17487/RFC8102, March 770 2017, . 772 Authors' Addresses 774 Peter Psenak (editor) 775 Cisco Systems 776 Eurovea Centre, Central 3 777 Pribinova Street 10 778 Bratislava 81109 779 Slovakia 781 Email: ppsenak@cisco.com 783 Les Ginsberg 784 Cisco Systems 785 821 Alder Drive 786 MILPITAS, CA 95035 787 USA 789 Email: ginsberg@cisco.com 791 Wim Henderickx 792 Nokia 793 Copernicuslaan 50 794 Antwerp, 2018 94089 795 Belgium 797 Email: wim.henderickx@nokia.com 798 Jeff Tantsura 799 Apstra 800 US 802 Email: jefftant.ietf@gmail.com 804 John Drake 805 Juniper Networks 806 1194 N. Mathilda Ave 807 Sunnyvale, California 94089 808 USA 810 Email: jdrake@juniper.net