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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in RFCs) == Unused Reference: 'RFC7794' is defined on line 398, but no explicit reference was found in the text == Outdated reference: A later version (-14) exists of draft-ietf-idr-bgpls-inter-as-topology-ext-09 Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--).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: December 24, 2021 Huawei Technologies 6 G. Mishra 7 Verizon Inc. 8 June 22, 2021 10 Passive Interface Attribute 11 draft-wang-lsr-passive-interface-attribute-07 13 Abstract 15 This document describes the mechanism that can be used to 16 differentiate the passive interfaces from the normal interfaces 17 within ISIS or OSPF domain. 19 Status of This Memo 21 This Internet-Draft is submitted in full conformance with the 22 provisions of BCP 78 and BCP 79. 24 Internet-Drafts are working documents of the Internet Engineering 25 Task Force (IETF). Note that other groups may also distribute 26 working documents as Internet-Drafts. The list of current Internet- 27 Drafts is at https://datatracker.ietf.org/drafts/current/. 29 Internet-Drafts are draft documents valid for a maximum of six months 30 and may be updated, replaced, or obsoleted by other documents at any 31 time. It is inappropriate to use Internet-Drafts as reference 32 material or to cite them other than as "work in progress." 34 This Internet-Draft will expire on December 24, 2021. 36 Copyright Notice 38 Copyright (c) 2021 IETF Trust and the persons identified as the 39 document authors. All rights reserved. 41 This document is subject to BCP 78 and the IETF Trust's Legal 42 Provisions Relating to IETF Documents 43 (https://trustee.ietf.org/license-info) in effect on the date of 44 publication of this document. Please review these documents 45 carefully, as they describe your rights and restrictions with respect 46 to this document. Code Components extracted from this document must 47 include Simplified BSD License text as described in Section 4.e of 48 the Trust Legal Provisions and are provided without warranty as 49 described in the Simplified BSD License. 51 Table of Contents 53 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 54 2. Conventions used in this document . . . . . . . . . . . . . . 3 55 3. Consideration for flagging passive interface . . . . . . . . 3 56 4. Passive Interface Attribute . . . . . . . . . . . . . . . . . 4 57 4.1. OSPFv2 Extended Stub-Link TLV . . . . . . . . . . . . . . 4 58 4.2. OSPFv3 Router-Stub-Link TLV . . . . . . . . . . . . . . . 5 59 4.3. ISIS Stub-link TLV . . . . . . . . . . . . . . . . . . . 6 60 4.4. Stub-Link Prefix Sub-TLV . . . . . . . . . . . . . . . . 6 61 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 62 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 63 7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 8 64 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 65 8.1. Normative References . . . . . . . . . . . . . . . . . . 8 66 8.2. Informative References . . . . . . . . . . . . . . . . . 9 67 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 69 1. Introduction 71 Passive interfaces are used commonly within an operators enterprise 72 or service provider networks. One of the most common use cases for 73 passive interface is in a data center Layer 2 and Layer 3 Top of 74 Rack(TOR) switch where the inter connected links between the TOR 75 switches and uplinks to the Core switch are only a few links and a 76 majority of the links are Layer 3 VLAN switched virtual interface 77 trunked between the TOR switches serving Layer 2 broadcast domains. 78 In this scenario all the VLANs are made passive as it is recommended 79 to limit the number of network LSAs between routers and switches to 80 avoid unnecessary hello processing overhead. 82 Another common use case is an inter-as routing scenario where the 83 same routing protocol but different IGP instance is running between 84 the adjacent BGP domains. Using passive interface on the inter-as 85 connections can ensure that prefixes contained within a domain are 86 only reachable within the domain itself and not allow the link state 87 database to be merged between domain which could result in 88 undesirable consequences. 90 For operator which runs different IGP domains that interconnect with 91 each other via the passive interfaces, there is desire to obtain the 92 inter-as topology information as described in 93 [I-D.ietf-idr-bgpls-inter-as-topology-ext]. If the router that runs 94 BGP-LS within one IGP domain can distinguish passive interfaces from 95 other normal interfaces, it is then easy for the router to report 96 these passive links using BGP-LS to a centralized PCE controller. 98 Draft [I-D.dunbar-lsr-5g-edge-compute-ospf-ext] describes the case 99 that edge compute server attach the network and needs to flood some 100 performance index information to the network to facilitate the 101 network select the optimized application resource. The edge compute 102 server will also not run IGP protocol. 104 And, passive interfaces are normally the boundary of one IGP domain, 105 knowing them can facilitate the operators to apply various policies 106 on such interfaces, for example, to secure their networks, or 107 filtering the incoming traffic with scrutiny. 109 But OSPF and ISIS have no position to flag such passive interface and 110 their associated attributes now. 112 This document defines the protocol extension for OSPF and ISIS to 113 indicate the passive interfaces and their associated attributes. 115 2. Conventions used in this document 117 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 118 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 119 document are to be interpreted as described in [RFC2119] . 121 3. Consideration for flagging passive interface 123 ISIS [RFC5029] defines the Link-Attributes Sub-TLV to carry the link 124 attribute information, but this Sub-TLV can only be carried within 125 the TLV 22, which is used to described the attached neighbor. For 126 passive interface, there is no ISIS neighbor, then it is not 127 appropriate to use this Sub-TLV to indicate the passive attribute of 128 the interface. 130 OSPFv2[RFC2328] defines link type field within Router LSA, the type 3 131 for connections to a stub network can be used to identified the 132 passive interface. But in OSPFv3 [RFC5340], type 3 within the 133 Router-LSA has been reserved. The information that associated with 134 stub network has been put in the Intra-Area-Prefix-LSAs. 136 It is necessary to define one general solution for ISIS and OSPF to 137 flag the passive interface and transfer the associated attributes 138 then. 140 4. Passive Interface Attribute 142 The following sections define the protocol extension to indicate the 143 passive interface and associated attributes in OSPFv2/v3 and ISIS. 145 4.1. OSPFv2 Extended Stub-Link TLV 147 [RFC7684] defines the OSPFv2 Extended Link Opaque LSA to contain the 148 additional link attribute TLV. Currently, only OSPFv2 Extended Link 149 TLV is defined to contain the link related sub-TLV. Because passive 150 interface is not the normal link that participate in the OSPFv2 151 process, we select to define one new top TLV within the OSPFv2 152 Extended Link Opaque LSA to contain the passive interface related 153 attribute information. 155 The OSPFv2 Extended Stub-Link TLV has the following format: 157 0 1 2 3 158 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 1 159 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 160 | Type(Stub-Link) | Length | 161 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 | Link ID | 163 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 164 | Link Data | 165 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 166 | Sub-TLVs (variable) | 167 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 168 Figure 1: OSPFv2 Extended Stub-Link TLV 170 Type: The TLV type. The value is 2(TBD) for this stub-link type 172 Length: Variable, dependent on sub-TLVs 174 Link ID: Link ID is defined in Section A.4.2 of [RFC2328] 176 Link Data: Link Data is defined in Section A.4.2 of [RFC2328] 178 Sub-TLVs: Existing sub-TLV that defined within "OSPFv2 Extended Link 179 TLV Sub-TLV" can be included if necessary, the definition of new sub- 180 TLV can refer to Section 4.4 182 If this TLV is advertised multiple times in the same OSPFv2 Extended 183 Link Opaque LSA, only the first instance of the TLV is used by 184 receiving OSPFv2 routers. This situation SHOULD be logged as an 185 error. 187 If this TLV is advertised multiple times for the same link in 188 different OSPFv2 Extended Link Opaque LSAs originated by the same 189 OSPFv2 router, the OSPFv2 Extended Stub-Link TLV in the OSPFv2 190 Extended Link Opaque LSA with the smallest Opaque ID is used by 191 receiving OSPFv2 routers. This situation may be logged as a warning. 193 It is RECOMMENDED that OSPFv2 routers advertising OSPFv2 Extended 194 Stub-Link TLVs in different OSPFv2 Extended Link Opaque LSAs re- 195 originate these LSAs in ascending order of Opaque ID to minimize the 196 disruption. 198 This document creates a registry for Stub-Link attribute in 199 Section 6. 201 4.2. OSPFv3 Router-Stub-Link TLV 203 [RFC8362] extend the LSA format by encoding the existing OSPFv3 LSA 204 [RFC5340] in TLV tuples and allowing advertisement of additional 205 information with additional TLV. 207 This document defines the Router-Stub-Link TLV to describes a single 208 router passive interface. The Router-Stub-Link TLV is only 209 applicable to the E-Router-LSA. Inclusion in other Extended LSA MUST 210 be ignored. 212 0 1 2 3 213 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 1 214 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 215 | Type(Router-Stub-Link) | Length | 216 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 217 | Interface ID | 218 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 219 | Sub-TLVs(Variable) | 220 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 221 Figure 2: OSPFv3 Router-Stub-Link TLV 223 Type: OSPFv3 Extended-LSA TLV Type. Value is 10(TBD) for Router- 224 Stub-Link TLV. 226 Length: Variable, dependent on sub-TLVs 228 Interface ID: 32-bit number uniquely identifying this interface among 229 the collection of this router's interfaces. For example, in some 230 implementations it may be possible to use the MIB-II IfIndex 231 [RFC2863]. 233 Sub-TLVs: Existing sub-TLV that defined within "OSPFv3 Extended-LSA 234 Sub-TLV" can be included if necessary. The definition of new sub-TLV 235 can refer to Section 4.4. 237 4.3. ISIS Stub-link TLV 239 This document defines one new top TLV to contain the passive 240 interface attributes, which is shown in Figure 4: 242 0 1 2 3 243 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 1 244 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 245 | Type(Stub-Link) | Length | 246 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 247 | Interface ID | 248 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 249 | Sub-TLVs(Variable) | 250 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 251 Figure 3: ISIS Stub-Link TLV 253 Type: ISIS TLV Codepoint. Value is 28(TBD) for stub-link TLV. 255 Length: Variable, dependent on sub-TLVs 257 Interface ID: 32-bit number uniquely identifying this interface among 258 the collection of this router's interfaces. For example, in some 259 implementations it may be possible to use the MIB-II IfIndex 260 [RFC2863]. 262 Sub-TLVs: Existing sub-TLV that defined within "Sub-TLVs for TLVs 22, 263 23, 25, 141, 222, and 223" can be included if necessary. The 264 definition of new sub-TLV can refer to Section 4.4. 266 4.4. Stub-Link Prefix Sub-TLV 268 This document defines one new sub-TLV that can be contained within 269 the OSPFv2 Extended Stub-Link TLV , OSPFv3 Router-Stub-Link TLV or 270 ISIS Stub-Link TLV, to describe the prefix information associated 271 with the passive interface. 273 The format of the sub-TLV is the followings: 275 0 1 2 3 276 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 1 277 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 278 | Type | Length | 279 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 280 | IPv4 Prefix or IPv6 Prefix Subobject | 281 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 282 Figure 4: Stub-Link Prefix Sub-TLV 284 Type: The TLV type. The value is 01(TBD) for this Stub-Link Prefix 285 type 287 Length: Variable, dependent on associated subobjects 289 Subobject: IPv4 prefix subobject or IPv6 prefix subobject, as that 290 defined in [RFC3209] 292 If the passive interface has multiple address, then multiple 293 subobjects will be included within this sub-TLV. 295 5. Security Considerations 297 Security concerns for ISIS are addressed in [RFC5304] and[RFC5310] 299 Security concern for OSPFv3 is addressed in [RFC4552] 301 Advertisement of the additional information defined in this document 302 introduces no new security concerns. 304 6. IANA Considerations 306 IANA is requested to the allocation in following registries: 308 +=========================+===========+======================+ 309 | Registry | Type | Meaning | 310 +=========================+===========+======================+ 311 |OSPFv2 Extended Link | 2 |Stub-Link TLV | 312 |Opaque LSA TLV | | | 313 +-------------------------+-----------+----------------------+ 314 |OSPFv3 Extended-LSA TLV | 10 |Router-Stub-Link TLV | 315 +-------------------------+-----------+----------------------+ 316 |IS-IS TLV Codepoint | 28 |Stub-Link TLV | 317 +-------------------------+-----------+----------------------+ 318 Figure 5: Newly defined TLV in existing IETF registry 320 IANA is requested to allocate one new registry that can be referred 321 by OSPFv2, OSPFv3 and ISIS respectively. 323 +=========================+==================================+ 324 | New Registry | Meaning | 325 +=========================+==================================+ 326 |Stub-Link Attribute | Attributes for stub-link | 327 +-------------------------+----------------------------------+ 328 Figure 6: Newly defined Registry for stub-link attributes 330 One new sub-TLV is defined in this document under this registry 331 codepoint: 333 +=========================+===========+===============================+ 334 | Registry | Type | Meaning | 335 +=========================+===========+===============================+ 336 |Stub-Link Attribute | 0 | Reserved 337 +=========================+===========+===============================+ 338 | | 1 |Stub-Link Prefix sub-TLV | 339 +-------------------------+-----------+-------------------------------+ 340 | | 2-65535 |Reserved | 341 +-------------------------+-----------+-------------------------------+ 342 Figure 7: Stub-Link Prefix Sub-TLV 344 7. Acknowledgement 346 Thanks Shunwan Zhang, Tony Li, Les Ginsberg, Acee Lindem, Dhruv 347 Dhody, Jeff Tantsura and Robert Raszuk for their suggestions and 348 comments on this idea. 350 8. References 352 8.1. Normative References 354 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 355 Requirement Levels", BCP 14, RFC 2119, 356 DOI 10.17487/RFC2119, March 1997, 357 . 359 [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, 360 DOI 10.17487/RFC2328, April 1998, 361 . 363 [RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group 364 MIB", RFC 2863, DOI 10.17487/RFC2863, June 2000, 365 . 367 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 368 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 369 Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, 370 . 372 [RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality 373 for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006, 374 . 376 [RFC5029] Vasseur, JP. and S. Previdi, "Definition of an IS-IS Link 377 Attribute Sub-TLV", RFC 5029, DOI 10.17487/RFC5029, 378 September 2007, . 380 [RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic 381 Authentication", RFC 5304, DOI 10.17487/RFC5304, October 382 2008, . 384 [RFC5310] Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R., 385 and M. Fanto, "IS-IS Generic Cryptographic 386 Authentication", RFC 5310, DOI 10.17487/RFC5310, February 387 2009, . 389 [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF 390 for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008, 391 . 393 [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., 394 Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute 395 Advertisement", RFC 7684, DOI 10.17487/RFC7684, November 396 2015, . 398 [RFC7794] Ginsberg, L., Ed., Decraene, B., Previdi, S., Xu, X., and 399 U. Chunduri, "IS-IS Prefix Attributes for Extended IPv4 400 and IPv6 Reachability", RFC 7794, DOI 10.17487/RFC7794, 401 March 2016, . 403 [RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and 404 F. Baker, "OSPFv3 Link State Advertisement (LSA) 405 Extensibility", RFC 8362, DOI 10.17487/RFC8362, April 406 2018, . 408 8.2. Informative References 410 [I-D.dunbar-lsr-5g-edge-compute-ospf-ext] 411 Dunbar, L., Chen, H., and A. Wang, "OSPF extension for 5G 412 Edge Computing Service", draft-dunbar-lsr-5g-edge-compute- 413 ospf-ext-04 (work in progress), March 2021. 415 [I-D.ietf-idr-bgpls-inter-as-topology-ext] 416 Wang, A., Chen, H., Talaulikar, K., and S. Zhuang, "BGP-LS 417 Extension for Inter-AS Topology Retrieval", draft-ietf- 418 idr-bgpls-inter-as-topology-ext-09 (work in progress), 419 September 2020. 421 Authors' Addresses 423 Aijun Wang 424 China Telecom 425 Beiqijia Town, Changping District 426 Beijing 102209 427 China 429 Email: wangaj3@chinatelecom.cn 431 Zhibo Hu 432 Huawei Technologies 433 Huawei Bld., No.156 Beiqing Rd. 434 Beijing 100095 435 China 437 Email: huzhibo@huawei.com 439 Gyan S. Mishra 440 Verizon Inc. 441 13101 Columbia Pike 442 Silver Spring MD 20904 443 United States of America 445 Email: gyan.s.mishra@verizon.com