idnits 2.17.1 draft-acee-ospf-admin-tags-05.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 12, 2016) is 2782 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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-23) exists of draft-ietf-ospf-ospfv3-lsa-extend-10 Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group A. Lindem, Ed. 3 Internet-Draft P. Psenak 4 Intended status: Standards Track Cisco Systems 5 Expires: March 16, 2017 September 12, 2016 7 Extensions to OSPF for Advertising Prefix/Link Administrative Tags 8 draft-acee-ospf-admin-tags-05.txt 10 Abstract 12 It is useful for routers in an OSPFv2 or OSPFv3 routing domain to be 13 able to associate tags with prefixes and links. Previously, OSPFv2 14 and OSPFv3 were relegated to a single tag for AS External and Not-So- 15 Stubby-Area (NSSA) prefixes. With the flexible encodings provided by 16 OSPFv2 Prefix/Link Attribute Advertisement and OSPFv3 Extended LSAs, 17 multiple administrative tags may advertised for all types of prefixes 18 and links. These administrative tags can be used for many 19 applications including route redistribution policy, selective prefix 20 prioritization, selective IP Fast-ReRoute (IPFRR) prefix protection, 21 and many others. 23 The ISIS protocol supports a similar mechanism that is described in 24 RFC 5130. 26 Status of This Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at http://datatracker.ietf.org/drafts/current/. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 This Internet-Draft will expire on March 16, 2017. 43 Copyright Notice 45 Copyright (c) 2016 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (http://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 Table of Contents 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 61 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3 62 2. 32-Bit Administrative Tag Sub-TLV . . . . . . . . . . . . . . 3 63 3. Administrative Tag Applicability . . . . . . . . . . . . . . 4 64 4. Protocol Operation . . . . . . . . . . . . . . . . . . . . . 5 65 4.1. Equal-Cost Multipath Applicability . . . . . . . . . . . 5 66 5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 67 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 68 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6 69 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 70 8.1. Normative References . . . . . . . . . . . . . . . . . . 6 71 8.2. Informative References . . . . . . . . . . . . . . . . . 7 72 Appendix A. 64-Bit Administrative Tag Sub-TLV . . . . . . . . . 7 73 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 75 1. Introduction 77 It is useful for routers in an OSPFv2 [OSPF] or OSPFv3 [OSPF] routing 78 domain to be able to associate tags with prefixes and links. 79 Previously, OSPFv3 and OSPFv3 were relegated to a single tag for AS 80 External and Not-So-Stubby-Area (NSSA) prefixes. With the flexible 81 encodings provided by OSPFv2 Prefix/Link Attribute Advertisement 82 ([OSPFV2-PREFIX-LINK]) and OSPFv3 Extended LSA 83 ([OSPFV3-EXTENDED-LSA]), multiple administrative tags may be 84 advertised for all types of prefixes and links. These administrative 85 tags can be used many applications including (but not limited to): 87 1. Controlling which routes are redistributed into other protocols 88 for readvertisement. 90 2. Prioritizing selected prefixes for faster convergence and 91 installation in the forwarding plane. 93 3. Identifying selected prefixes for Loop-Free Alternative (LFA) 94 protection. 96 Throughout this document, OSPF is used when the text applies to both 97 OSPFv2 and OSPFv3. OSPFv2 or OSPFv3 is used when the text is 98 specific to one version of the OSPF protocol. 100 The ISIS protocol supports a similar mechanism that is described in 101 RFC 5130 [ISIS-ADMIN-TAGS]. 103 1.1. Requirements notation 105 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 106 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 107 document are to be interpreted as described in [RFC-KEYWORDS]. 109 2. 32-Bit Administrative Tag Sub-TLV 111 This document creates a new Administrative Tag Sub-TLV for OSPFv2 and 112 OSPFv3. This Sub-TLV specifies one or more 32-bit unsigned integers 113 that may be associated with an OSPF advertised prefix or OSPF Link. 114 The precise usage of these tags is beyond the scope of this document. 116 The format of this Sub-TLV is the same as the format used by the 117 Traffic Engineering Extensions to OSPF [TE]. The LSA payload 118 consists of one or more nested Type/Length/Value (TLV) triplets. The 119 format of each TLV is: 121 0 1 2 3 122 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 1 123 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 124 | Type | Length | 125 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 126 | Value... | 127 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 129 TLV Format 131 The Length field defines the length of the value portion in octets 132 (thus a TLV with no value portion would have a length of 0). The TLV 133 is padded to 4-octet alignment; padding is not included in the length 134 field (so a 3-octet value would have a length of 3, but the total 135 size of the TLV would be 8 octets). 137 The format of the 32-bit Administrative Tag TLV is as follows: 139 0 1 2 3 140 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 1 141 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 142 | Type | Length | 143 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 144 | First 32-bit Administrative Tag | 145 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 146 | o | 147 o 148 | o | 149 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 150 | Last 32-bit Administrative Tag | 151 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 153 Type A 16-bit field set to TBD. The value MAY be different 154 depending upon the IANA registry from which it is 155 allocated. 157 Length A 16-bit field that indicates the length of the value 158 portion in octets and will be a multiple of 4 octets 159 dependent on the number of administrative tags 160 advertised. If the sub-TLV is specified, at least one 161 administrative tag must be advertised. 163 Value A variable length list of one or more administrative 164 tags. 166 32-bit Administrative Tag Sub-TLV 168 This sub-TLV will carry one or more 32-bit unsigned integer values 169 that will be used as administrative tags. 171 3. Administrative Tag Applicability 173 The administrative tag TLV specified herein will be valid as a sub- 174 TLV of the following TLVs specified in [OSPFV2-PREFIX-LINK]: 176 1. Extended Prefix TLV advertised in the OSPFv2 Extended Prefix LSA 178 2. Extended Link TLV advertised in the OSPFv2 Extended Prefix LSA 180 The administrative tag TLV specified herein will be valid as a sub- 181 TLV of the following TLVs specified in [OSPFV3-EXTENDED-LSA]: 183 1. Router-Link TLV advertised in the E-Router-LSA 185 2. Inter-Area-Prefix TLV advertised in the E-Inter-Area-Prefix-LSA 186 3. Intra-Area-Prefix TLV advertised in the E-Link-LSA and the E- 187 Intra-Area-LSA 189 4. External-Prefix TLV advertised in the E-AS-External-LSA and the 190 E-NSSA-LSA 192 4. Protocol Operation 194 An OSPF router supporting this specification MUST propagate 195 administrative tags when acting as an Area Border Router and 196 originating summary advertisements into other areas. Similarly, an 197 OSPF router supporting this specification and acting as an ABR for a 198 Not-So-Stubby Area (NSSA) MUST propagate tags when translating NSSA 199 routes to AS External advertisements [NSSA]. The number of tags 200 supported MAY limit the number of tags that are propagated. When 201 propagating multiple tags, the order of the the tags must be 202 preserved. 204 For configured area ranges, NSSA ranges, and configurated 205 summarization of redistributed routes, tags from component routes 206 SHOULD NOT be propagated to the summary. Implementations SHOULD 207 provide a mechanism to configure tags for area ranges, NSSA ranges, 208 and redistributed route summaries. 210 An OSPF router supporting this specification MUST be able to 211 advertise and interpret one 32-bit tag for prefixes and links. An 212 OSPF router supporting this specification MAY be able to advertise 213 and propagate multiple 32-bit tags. The maximum tags that an 214 implementation supports is a local matter depending upon supported 215 applications using the prefix or link tags. 217 When a single tag is advertised for AS External or NSSA LSA prefix, 218 the existing tag in OSPFv2 and OSPFv3 AS-External-LSA and NSSA-LSA 219 encodings SHOULD be utilized. This will facilitate backward 220 compatibilty with implementations that do not support this 221 specification. 223 4.1. Equal-Cost Multipath Applicability 225 When multiple LSAs contribute to an OSPF route, it is possible that 226 these LSAs will all have different tags. In this situation, the OSPF 227 router MUST associate the tags from one of the LSAs contributing a 228 path and, if the implementation supports multiple tags, MAY associate 229 tags for multiple contributing LSAs up to the maximum number of tags 230 supported. 232 5. Security Considerations 234 This document describes both a generic mechanism for advertising 235 administrative tags for OSPF prefixes and links. The administrative 236 tags are generally less critical than the topology information 237 currently advertised by the base OSPF protocol. The security 238 considerations for the generic mechanism are dependent on the future 239 application and, as such, should be described as additional 240 capabilities are proposed for advertisement. Security considerations 241 for the base OSPF protocol are covered in [OSPF] and [OSPFV3]. 243 6. IANA Considerations 245 The following values should be allocated from the OSPF Extended 246 Prefix TLV Sub-TLV Registry [OSPFV2-PREFIX-LINK]: 248 o TBD - 32-bit Administrative Tag TLV 250 The following values should be allocated from the OSPF Extended Link 251 TLV Sub-TLV Registry [OSPFV2-PREFIX-LINK]: 253 o TBD - 32-bit Administrative Tag TLV 255 The following values should be allocated from the OSPFv3 Extended-LSA 256 Sub-TLV Registry [OSPFV3-EXTENDED-LSA]: 258 o TBD - 32-bit Administrative Tag TLV 260 7. Acknowledgments 262 The authors of RFC 5130 are acknowledged since this document draws 263 upon both the ISIS specification and deployment experience. 265 Thanks to Donnie Savage for his comments and questions. 267 The RFC text was produced using Marshall Rose's xml2rfc tool. 269 8. References 271 8.1. Normative References 273 [OSPF] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. 275 [OSPFV2-PREFIX-LINK] 276 Psenak, P., Gredler, H., Shakir, R., Henderickx, W., 277 Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute 278 Advertisement", RFC 7684, November 2015. 280 [OSPFV3] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF 281 for IPv6", RFC 5340, July 2008. 283 [OSPFV3-EXTENDED-LSA] 284 Lindem, A., Mirtorabi, S., Roy, A., and F. Baker, "OSPFv3 285 LSA Extendibility", draft-ietf-ospf-ospfv3-lsa-extend- 286 10.txt (work in progress), . 288 [RFC-KEYWORDS] 289 Bradner, S., "Key words for use in RFC's to Indicate 290 Requirement Levels", BCP 14, RFC 2119, March 1997. 292 [TE] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering 293 Extensions to OSPF", RFC 3630, September 2003. 295 8.2. Informative References 297 [ISIS-ADMIN-TAGS] 298 Previdi, S., Shand, M., and C. Martin, "A Policy Control 299 Mechanism in IS-IS Using Administrative Tags", RFC 5130, 300 February 2008. 302 [NSSA] Murphy, P., "The OSPF Not-So-Stubby Area (NSSA) Option", 303 RFC 3101, January 2003. 305 Appendix A. 64-Bit Administrative Tag Sub-TLV 307 The definition of the 64-bit tag was considered but discard given 308 that there is no strong requirement or use case. The specification 309 is included here for information. 311 This sub-TLV will carry one or more 64-bit unsigned integer values 312 that will be used as administrative tags. 314 The format of the 64-bit Administrative Tag TLV is as follows: 316 0 1 2 3 317 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 1 318 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 319 | Type | Length | 320 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 321 | First 64-bit Administrative Tag | 322 | | 323 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 324 | o | 325 o 326 | o | 327 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 328 | Last 64-bit Administrative Tag | 329 | | 330 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 332 Type A 16-bit field set to TBD. The value MAY be different 333 depending upon the registry from which it is allocated. 335 Length A 16-bit field that indicates the length of the value 336 portion in octets and will be a multiple of 8 octets 337 dependent on the number of administrative tags 338 advertised. If the sub-TLV is specified, at least one 339 administrative tag must be advertised. 341 Value A variable length list of one or more 64-bit 342 administrative tags. 344 64-bit Administrative Tag TLV 346 Authors' Addresses 348 Acee Lindem (editor) 349 Cisco Systems 350 301 Midenhall Way 351 Cary, NC 27513 352 USA 354 Email: acee@cisco.com 355 Peter Psenak 356 Cisco Systems 357 Apollo Business Center 358 Mlynske nivy 43 359 Bratislava, 821 09 360 Slovakia 362 Email: ppsenak@cisco.com