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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in RFCs) == Unused Reference: 'RFC7794' is defined on line 450, but no explicit reference was found in the text == Outdated reference: A later version (-15) exists of draft-ietf-idr-bgpls-inter-as-topology-ext-09 Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--).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 A. Wang 3 Internet-Draft China Telecom 4 Intended status: Standards Track Z. Hu 5 Expires: January 13, 2022 Huawei Technologies 6 G. Mishra 7 Verizon Inc. 8 J. Sun 9 ZTE Corporation 10 July 12, 2021 12 Passive Interface Attribute 13 draft-wang-lsr-passive-interface-attribute-08 15 Abstract 17 This document describes the mechanism that can be used to 18 differentiate the passive interfaces from the normal interfaces 19 within ISIS or OSPF domain. 21 Status of This Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at https://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on January 13, 2022. 38 Copyright Notice 40 Copyright (c) 2021 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents 45 (https://trustee.ietf.org/license-info) in effect on the date of 46 publication of this document. Please review these documents 47 carefully, as they describe your rights and restrictions with respect 48 to this document. Code Components extracted from this document must 49 include Simplified BSD License text as described in Section 4.e of 50 the Trust Legal Provisions and are provided without warranty as 51 described in the Simplified BSD License. 53 Table of Contents 55 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 56 2. Conventions used in this document . . . . . . . . . . . . . . 3 57 3. Consideration for flagging passive interface . . . . . . . . 3 58 4. Passive Interface Attribute . . . . . . . . . . . . . . . . . 4 59 4.1. OSPFv2 Extended Stub-Link TLV . . . . . . . . . . . . . . 4 60 4.2. OSPFv3 Router-Stub-Link TLV . . . . . . . . . . . . . . . 5 61 4.3. ISIS Stub-link TLV . . . . . . . . . . . . . . . . . . . 6 62 4.4. Stub-Link Prefix Sub-TLV . . . . . . . . . . . . . . . . 7 63 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8 64 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 65 7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 9 66 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 67 8.1. Normative References . . . . . . . . . . . . . . . . . . 9 68 8.2. Informative References . . . . . . . . . . . . . . . . . 10 69 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 71 1. Introduction 73 Passive interfaces are used commonly within an operators enterprise 74 or service provider networks. One of the most common use cases for 75 passive interface is in a data center Layer 2 and Layer 3 Top of 76 Rack(TOR) switch where the inter connected links between the TOR 77 switches and uplinks to the Core switch are only a few links and a 78 majority of the links are Layer 3 VLAN switched virtual interface 79 trunked between the TOR switches serving Layer 2 broadcast domains. 80 In this scenario all the VLANs are made passive as it is recommended 81 to limit the number of network LSAs between routers and switches to 82 avoid unnecessary hello processing overhead. 84 Another common use case is an inter-as routing scenario where the 85 same routing protocol but different IGP instance is running between 86 the adjacent BGP domains. Using passive interface on the inter-as 87 connections can ensure that prefixes contained within a domain are 88 only reachable within the domain itself and not allow the link state 89 database to be merged between domain which could result in 90 undesirable consequences. 92 For operator which runs different IGP domains that interconnect with 93 each other via the passive interfaces, there is desire to obtain the 94 inter-as topology information as described in 95 [I-D.ietf-idr-bgpls-inter-as-topology-ext]. If the router that runs 96 BGP-LS within one IGP domain can distinguish passive interfaces from 97 other normal interfaces, it is then easy for the router to report 98 these passive links using BGP-LS to a centralized PCE controller. 100 Draft [I-D.dunbar-lsr-5g-edge-compute-ospf-ext] describes the case 101 that edge compute server attach the network and needs to flood some 102 performance index information to the network to facilitate the 103 network select the optimized application resource. The edge compute 104 server will also not run IGP protocol. 106 And, passive interfaces are normally the boundary of one IGP domain, 107 knowing them can facilitate the operators to apply various policies 108 on such interfaces, for example, to secure their networks, or 109 filtering the incoming traffic with scrutiny. 111 But OSPF and ISIS have no position to flag such passive interface and 112 their associated attributes now. 114 This document defines the protocol extension for OSPF and ISIS to 115 indicate the passive interfaces and their associated attributes. 117 2. Conventions used in this document 119 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 120 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 121 document are to be interpreted as described in [RFC2119] . 123 3. Consideration for flagging passive interface 125 ISIS [RFC5029] defines the Link-Attributes Sub-TLV to carry the link 126 attribute information, but this Sub-TLV can only be carried within 127 the TLV 22, which is used to described the attached neighbor. For 128 passive interface, there is no ISIS neighbor, then it is not 129 appropriate to use this Sub-TLV to indicate the passive attribute of 130 the interface. 132 OSPFv2[RFC2328] defines link type field within Router LSA, the type 3 133 for connections to a stub network can be used to identified the 134 passive interface. But in OSPFv3 [RFC5340], type 3 within the 135 Router-LSA has been reserved. The information that associated with 136 stub network has been put in the Intra-Area-Prefix-LSAs. 138 It is necessary to define one general solution for ISIS and OSPF to 139 flag the passive interface and transfer the associated attributes 140 then. 142 4. Passive Interface Attribute 144 The following sections define the protocol extension to indicate the 145 passive interface and associated attributes in OSPFv2/v3 and ISIS. 147 4.1. OSPFv2 Extended Stub-Link TLV 149 [RFC7684] defines the OSPFv2 Extended Link Opaque LSA to contain the 150 additional link attribute TLV. Currently, only OSPFv2 Extended Link 151 TLV is defined to contain the link related sub-TLV. Because passive 152 interface is not the normal link that participate in the OSPFv2 153 process, we select to define one new top TLV within the OSPFv2 154 Extended Link Opaque LSA to contain the passive interface related 155 attribute information. 157 The OSPFv2 Extended Stub-Link TLV has the following format: 159 0 1 2 3 160 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 1 161 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 | Type(Stub-Link) | Length | 163 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 164 | Link Type | Reserved | Metric | 165 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 166 | Link ID | 167 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 168 | Link Data | 169 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 170 | Sub-TLVs (variable) | 171 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 172 Figure 1: OSPFv2 Extended Stub-Link TLV 174 Type: The TLV type. The value is 2(TBD) for this stub-link type 176 Length: Variable, dependent on sub-TLVs 178 Link Type: Define the type of the stub-link. This document defines 179 the followings type: 181 o 0: Reserved 183 o 1: AS boundary link 185 o 2: Loopback link 187 o 3: Vlan interface link 189 o 4-255: For future extension 190 Metric: Link metric used for inter-AS traffic engineering. 192 Link ID: Link ID is defined in Section A.4.2 of [RFC2328] 194 Link Data: Link Data is defined in Section A.4.2 of [RFC2328] 196 Sub-TLVs: Existing sub-TLV that defined within "OSPFv2 Extended Link 197 TLV Sub-TLV" can be included if necessary, the definition of new sub- 198 TLV can refer to Section 4.4 200 If this TLV is advertised multiple times in the same OSPFv2 Extended 201 Link Opaque LSA, only the first instance of the TLV is used by 202 receiving OSPFv2 routers. This situation SHOULD be logged as an 203 error. 205 If this TLV is advertised multiple times for the same link in 206 different OSPFv2 Extended Link Opaque LSAs originated by the same 207 OSPFv2 router, the OSPFv2 Extended Stub-Link TLV in the OSPFv2 208 Extended Link Opaque LSA with the smallest Opaque ID is used by 209 receiving OSPFv2 routers. This situation may be logged as a warning. 211 It is RECOMMENDED that OSPFv2 routers advertising OSPFv2 Extended 212 Stub-Link TLVs in different OSPFv2 Extended Link Opaque LSAs re- 213 originate these LSAs in ascending order of Opaque ID to minimize the 214 disruption. 216 This document creates a registry for Stub-Link attribute in 217 Section 6. 219 4.2. OSPFv3 Router-Stub-Link TLV 221 [RFC8362] extend the LSA format by encoding the existing OSPFv3 LSA 222 [RFC5340] in TLV tuples and allowing advertisement of additional 223 information with additional TLV. 225 This document defines the Router-Stub-Link TLV to describes a single 226 router passive interface. The Router-Stub-Link TLV is only 227 applicable to the E-Router-LSA. Inclusion in other Extended LSA MUST 228 be ignored. 230 0 1 2 3 231 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 1 232 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 233 | Type(Router-Stub-Link) | Length | 234 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 235 | Link Type | Reserved | Metric | 236 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 237 | Interface ID | 238 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 239 | Sub-TLVs(Variable) | 240 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 241 Figure 2: OSPFv3 Router-Stub-Link TLV 243 Type: OSPFv3 Extended-LSA TLV Type. Value is 10(TBD) for Router- 244 Stub-Link TLV. 246 Length: Variable, dependent on sub-TLVs 248 Link Type: Define the type of the stub-link. This document defines 249 the followings type: 251 o 0: Reserved 253 o 1: AS boundary link 255 o 2: Loopback link 257 o 3: Vlan interface link 259 o 4-255: For future extension 261 Metric: Link metric used for inter-AS traffic engineering. 263 Interface ID: 32-bit number uniquely identifying this interface among 264 the collection of this router's interfaces. For example, in some 265 implementations it may be possible to use the MIB-II IfIndex 266 [RFC2863]. 268 Sub-TLVs: Existing sub-TLV that defined within "OSPFv3 Extended-LSA 269 Sub-TLV" can be included if necessary. The definition of new sub-TLV 270 can refer to Section 4.4. 272 4.3. ISIS Stub-link TLV 274 This document defines one new top TLV to contain the passive 275 interface attributes, which is shown in Figure 4: 277 0 1 2 3 278 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 1 279 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 280 | Type(Stub-Link) | Length | 281 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 282 | Link Type | Reserved | Metric | 283 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 284 | Interface ID | 285 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 286 | Sub-TLVs(Variable) | 287 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 288 Figure 3: ISIS Stub-Link TLV 290 Type: ISIS TLV Codepoint. Value is 28(TBD) for stub-link TLV. 292 Length: Variable, dependent on sub-TLVs 294 Link Type: Define the type of the stub-link. This document defines 295 the followings type: 297 o 0: Reserved 299 o 1: AS boundary link 301 o 2: Loopback link 303 o 3: Vlan interface link 305 o 4-255: For future extension 307 Metric: Link metric used for inter-AS traffic engineering. 309 Interface ID: 32-bit number uniquely identifying this interface among 310 the collection of this router's interfaces. For example, in some 311 implementations it may be possible to use the MIB-II IfIndex 312 [RFC2863]. 314 Sub-TLVs: Existing sub-TLV that defined within "Sub-TLVs for TLVs 22, 315 23, 25, 141, 222, and 223" can be included if necessary. The 316 definition of new sub-TLV can refer to Section 4.4. 318 4.4. Stub-Link Prefix Sub-TLV 320 This document defines one new sub-TLV that can be contained within 321 the OSPFv2 Extended Stub-Link TLV , OSPFv3 Router-Stub-Link TLV or 322 ISIS Stub-Link TLV, to describe the prefix information associated 323 with the passive interface. 325 The format of the sub-TLV is the followings: 327 0 1 2 3 328 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 1 329 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 330 | Type | Length | 331 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 332 | IPv4 Prefix or IPv6 Prefix Subobject | 333 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 334 Figure 4: Stub-Link Prefix Sub-TLV 336 Type: The TLV type. The value is 01(TBD) for this Stub-Link Prefix 337 type 339 Length: Variable, dependent on associated subobjects 341 Subobject: IPv4 prefix subobject or IPv6 prefix subobject, as that 342 defined in [RFC3209] 344 If the passive interface has multiple address, then multiple 345 subobjects will be included within this sub-TLV. 347 5. Security Considerations 349 Security concerns for ISIS are addressed in [RFC5304] and[RFC5310] 351 Security concern for OSPFv3 is addressed in [RFC4552] 353 Advertisement of the additional information defined in this document 354 introduces no new security concerns. 356 6. IANA Considerations 358 IANA is requested to the allocation in following registries: 360 +=========================+===========+======================+ 361 | Registry | Type | Meaning | 362 +=========================+===========+======================+ 363 |OSPFv2 Extended Link | 2 |Stub-Link TLV | 364 |Opaque LSA TLV | | | 365 +-------------------------+-----------+----------------------+ 366 |OSPFv3 Extended-LSA TLV | 10 |Router-Stub-Link TLV | 367 +-------------------------+-----------+----------------------+ 368 |IS-IS TLV Codepoint | 28 |Stub-Link TLV | 369 +-------------------------+-----------+----------------------+ 370 Figure 5: Newly defined TLV in existing IETF registry 372 IANA is requested to allocate one new registry that can be referred 373 by OSPFv2, OSPFv3 and ISIS respectively. 375 +=========================+==================================+ 376 | New Registry | Meaning | 377 +=========================+==================================+ 378 |Stub-Link Attribute | Attributes for stub-link | 379 +-------------------------+----------------------------------+ 380 Figure 6: Newly defined Registry for stub-link attributes 382 One new sub-TLV is defined in this document under this registry 383 codepoint: 385 +=========================+===========+===============================+ 386 | Registry | Type | Meaning | 387 +=========================+===========+===============================+ 388 |Stub-Link Attribute | 0 | Reserved 389 +=========================+===========+===============================+ 390 | | 1 |Stub-Link Prefix sub-TLV | 391 +-------------------------+-----------+-------------------------------+ 392 | | 2-65535 |Reserved | 393 +-------------------------+-----------+-------------------------------+ 394 Figure 7: Stub-Link Prefix Sub-TLV 396 7. Acknowledgement 398 Thanks Shunwan Zhang, Tony Li, Les Ginsberg, Acee Lindem, Dhruv 399 Dhody, Jeff Tantsura and Robert Raszuk for their suggestions and 400 comments on this idea. 402 8. References 404 8.1. Normative References 406 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 407 Requirement Levels", BCP 14, RFC 2119, 408 DOI 10.17487/RFC2119, March 1997, 409 . 411 [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, 412 DOI 10.17487/RFC2328, April 1998, 413 . 415 [RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group 416 MIB", RFC 2863, DOI 10.17487/RFC2863, June 2000, 417 . 419 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 420 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 421 Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, 422 . 424 [RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality 425 for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006, 426 . 428 [RFC5029] Vasseur, JP. and S. Previdi, "Definition of an IS-IS Link 429 Attribute Sub-TLV", RFC 5029, DOI 10.17487/RFC5029, 430 September 2007, . 432 [RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic 433 Authentication", RFC 5304, DOI 10.17487/RFC5304, October 434 2008, . 436 [RFC5310] Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R., 437 and M. Fanto, "IS-IS Generic Cryptographic 438 Authentication", RFC 5310, DOI 10.17487/RFC5310, February 439 2009, . 441 [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF 442 for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008, 443 . 445 [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., 446 Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute 447 Advertisement", RFC 7684, DOI 10.17487/RFC7684, November 448 2015, . 450 [RFC7794] Ginsberg, L., Ed., Decraene, B., Previdi, S., Xu, X., and 451 U. Chunduri, "IS-IS Prefix Attributes for Extended IPv4 452 and IPv6 Reachability", RFC 7794, DOI 10.17487/RFC7794, 453 March 2016, . 455 [RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and 456 F. Baker, "OSPFv3 Link State Advertisement (LSA) 457 Extensibility", RFC 8362, DOI 10.17487/RFC8362, April 458 2018, . 460 8.2. Informative References 462 [I-D.dunbar-lsr-5g-edge-compute-ospf-ext] 463 Dunbar, L., Chen, H., and A. Wang, "OSPF extension for 5G 464 Edge Computing Service", draft-dunbar-lsr-5g-edge-compute- 465 ospf-ext-04 (work in progress), March 2021. 467 [I-D.ietf-idr-bgpls-inter-as-topology-ext] 468 Wang, A., Chen, H., Talaulikar, K., and S. Zhuang, "BGP-LS 469 Extension for Inter-AS Topology Retrieval", draft-ietf- 470 idr-bgpls-inter-as-topology-ext-09 (work in progress), 471 September 2020. 473 Authors' Addresses 475 Aijun Wang 476 China Telecom 477 Beiqijia Town, Changping District 478 Beijing 102209 479 China 481 Email: wangaj3@chinatelecom.cn 483 Zhibo Hu 484 Huawei Technologies 485 Huawei Bld., No.156 Beiqing Rd. 486 Beijing 100095 487 China 489 Email: huzhibo@huawei.com 491 Gyan S. Mishra 492 Verizon Inc. 493 13101 Columbia Pike 494 Silver Spring MD 20904 495 United States of America 497 Email: gyan.s.mishra@verizon.com 499 Jinsong Sun 500 ZTE Corporation 501 No. 68, Ziijnhua Road 502 Nan Jing 210012 503 China 505 Email: sun.jinsong@zte.com.cn