idnits 2.17.1 draft-ietf-l1vpn-ospf-auto-discovery-04.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** It looks like you're using RFC 3978 boilerplate. You should update this to the boilerplate described in the IETF Trust License Policy document (see https://trustee.ietf.org/license-info), which is required now. -- Found old boilerplate from RFC 3978, Section 5.1 on line 16. -- Found old boilerplate from RFC 3978, Section 5.5, updated by RFC 4748 on line 479. -- Found old boilerplate from RFC 3979, Section 5, paragraph 1 on line 490. -- Found old boilerplate from RFC 3979, Section 5, paragraph 2 on line 497. -- Found old boilerplate from RFC 3979, Section 5, paragraph 3 on line 503. 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 Copyright Line does not match the current year -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (December 3, 2007) is 5987 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) -- Possible downref: Normative reference to a draft: ref. 'L1VPN-BM' -- No information found for draft-ouldbrahim-l1vpn-bgp-auto-discovery-work - is the name correct? Summary: 1 error (**), 0 flaws (~~), 1 warning (==), 9 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Internet Draft Igor Bryskin (ADVA Optical Networking) 2 Category: Standards Track Lou Berger (LabN Consulting, LLC) 3 Expiration Date: June 3, 2008 5 December 3, 2007 7 OSPF Based Layer 1 VPN Auto-Discovery 9 draft-ietf-l1vpn-ospf-auto-discovery-04.txt 11 Status of this Memo 13 By submitting this Internet-Draft, each author represents that any 14 applicable patent or other IPR claims of which he or she is aware 15 have been or will be disclosed, and any of which he or she becomes 16 aware will be disclosed, in accordance with Section 6 of BCP 79. 18 Internet-Drafts are working documents of the Internet Engineering 19 Task Force (IETF), its areas, and its working groups. Note that 20 other groups may also distribute working documents as Internet- 21 Drafts. 23 Internet-Drafts are draft documents valid for a maximum of six months 24 and may be updated, replaced, or obsoleted by other documents at any 25 time. It is inappropriate to use Internet-Drafts as reference 26 material or to cite them other than as "work in progress." 28 The list of current Internet-Drafts can be accessed at 29 http://www.ietf.org/1id-abstracts.html 31 The list of Internet-Draft Shadow Directories can be accessed at 32 http://www.ietf.org/shadow.html 34 This Internet-Draft will expire on June 3, 2008. 36 Copyright Notice 38 Copyright (C) The IETF Trust (2007). 40 Abstract 42 This document defines an Open Shortest Path First (OSPF) based 43 Layer-1 Virtual Private Network (L1VPN) auto-discovery mechanism. 44 This mechanism enables provider edge (PE) devices using OSPF to 45 dynamically learn about existence of each other, and attributes of 46 configured customer edge (CE) links and their associations with 47 L1VPNs. This document builds on L1VPN framework and requirements, 48 and provides a L1VPN basic mode auto-discovery mechanism. 50 Contents 52 1 Introduction .............................................. 3 53 1.1 Terminology ............................................... 3 54 1.2 Overview .................................................. 4 55 2 L1VPN LSA and its TLVs .................................... 5 56 2.1 L1VPN LSA ................................................. 5 57 2.2 L1VPN INFO TLV ............................................ 6 58 3 L1VPN LSA Advertising and Processing ...................... 8 59 3.1 Discussion and Example .................................... 8 60 4 Backward Compatibility .................................... 9 61 5 Security Considerations ................................... 10 62 6 IANA Considerations ....................................... 10 63 7 Acknowledgment ............................................ 10 64 8 References ................................................ 11 65 8.1 Normative References ...................................... 11 66 8.2 Informative References .................................... 11 67 9 Authors' Addresses ........................................ 12 68 10 Full Copyright Statement .................................. 12 69 11 Intellectual Property ..................................... 12 70 Conventions used in this document 72 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 73 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 74 document are to be interpreted as described in [RFC2119]. 76 1. Introduction 78 1.1. Terminology 80 The reader of this document should be familiar with the terms used in 81 [RFC4847] and [L1VPN-BM]. In particular the following terms: 83 L1VPN - Layer One Virtual Private Network 85 CE - Customer (edge) network element directly connected to the 86 Provider network (terminates one or more links to one or 87 more PEs); it is also connected to one or more Cs and/or 88 other CEs 90 C - Customer network element that is not connected to the 91 Provider network but is connected to one or more other Cs 92 and/or CEs 94 PE - Provider (edge) network element directly connected to one or 95 more Customer networks (terminates one or more links to one 96 or more CEs associated with the same or different L1VPNs); 97 it is also connected to one or more PR and/or other PEs 99 P - Provider (core) network element that is not directly 100 connected to any of Customer networks; P is connected to one 101 or more other Ps and/or PEs 103 LSDB - Link State Database: a data structure supported by an IGP 104 speaker 106 PIT - Port Information Table 108 CPI - Customer Port Identifier 110 PPI - Provider Port Identifier 112 1.2. Overview 114 The framework for Layer 1 VPNs is described in [RFC4847]. Basic mode 115 operation is further defined in [L1VPN-BM]. [L1VPN-BM] document 116 identifies the information that is necessary to map customer 117 information (ports identifiers) to provider information 118 (identifiers). It also states that this mapping information may be 119 provided via provisioning or via an auto-discovery mechanism. This 120 document provides such an auto-discovery mechanism using Open 121 Shortest Path First (OSPF). 123 Figure 1 shows the L1VPN basic service being supported using OSPF 124 based L1VPN auto-discovery. This figure shows two PE routers 125 interconnected over a GMPLS backbone. Each PE is attached to three 126 CE devices belonging to three different Cons. In this network, OSPF 127 is used to provide the VPN membership, port mapping and related 128 information required to support basic mode operation. 130 PE PE 131 +---------+ +--------------+ 132 +--------+ | +------+| | +----------+ | +--------+ 133 | VPN-A | | |VPN-A || | | VPN-A | | | VPN-A | 134 | CE1 |--| |PIT || OSPF LSAs | | PIT | |-| CE2 | 135 +--------+ | | ||<----------->| | | | +--------+ 136 | +------+| Distribution| +----------+ | 137 | | | | 138 +--------+ | +------+| | +----------+ | +--------+ 139 | VPN-B | | |VPN-B || ------- | | VPN-B | | | VPN-B | 140 | CE1 |--| |PIT ||--( GMPLS )--| | PIT | |-| CE2 | 141 +--------+ | | || (Backbone) | | | | +--------+ 142 | +------+| -------- | +----------+ | 143 | | | | 144 +--------+ | +-----+ | | +----------+ | +--------+ 145 | VPN-C | | |VPN-C| | | | VPN-C | | | VPN-C | 146 | CE1 |--| |PIT | | | | PIT | |-| CE2 | 147 +--------+ | | | | | | | | +--------+ 148 | +-----+ | | +----------+ | 149 +---------+ +--------------+ 151 Figure 1: OSPF Auto-Discovery for L1VPNs 153 See [L1VPN-BGP] for a parallel L1VPN auto-discovery that uses BGP. 154 The OSPF approach described in this document is particularly useful 155 in networks where BGP is not typically used. 157 The approach used in this document to provide OSPF based L1VPN auto- 158 discovery uses a new type of Opaque Link State Advertisement (LSA) 159 which is referred to as an L1VPN LSA. The L1VPN LSA carries 160 information in TLV (type, length, value) structures. An L1VPN 161 specific TLV is defined in below to propagate VPN membership and port 162 information. This TLV is is referred to as the L1VPN Info TLV. The 163 L1VPN LSA may also carry Traffic Engineering (TE) TLVs, see [RFC3630] 164 and [RFC4203]. 166 2. L1VPN LSA and its TLVs 168 This section defines the L1VPN LSA and its TLVs. 170 2.1. L1VPN LSA 172 The format of a L1VPN LSA is as follows: 174 0 1 2 3 175 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 1 176 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 177 | LS age | Options | LS Type | 178 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 179 | Opaque Type | Opaque ID | 180 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 181 | Advertising Router | 182 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 | LS Sequence Number | 184 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 | LS checksum | Length | 186 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 | L1VPN Info TLV | 188 | ... | 189 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 190 | TE Link TLV | 191 | ... | 192 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 194 LS age 195 As defined in [RFC2328] 197 Options 198 As defined in [RFC2328]. 200 LS Type 201 This field MUST be set to 11. 203 Opaque Type 204 The value of this field MUST be set to TBA (by IANA). 206 Opaque ID 207 As defined in [RFC2370]. 209 Advertising Router 210 As defined in [RFC2328]. 212 LS Sequence Number 213 As defined in [RFC2328]. 215 LS checksum 216 As defined in [RFC2328]. 218 Length 219 As defined in [RFC2328]. 221 L1VPN Info TLV 222 A single TLV, as defined in section 3.2, MUST be present. 223 If more than one L1VPN Info TLV is present, only the first TLV is 224 processed and the others MUST be ignored on receipt. 226 TE Link TLV 227 A single TE Link TLV (as defined in [RFC3630] and [RFC4203]) 228 MAY be included in a L1VPN LSA 230 2.2. L1VPN INFO TLV 232 The following TLV is introduced: 234 Name: L1VPN IPv4 Info 235 Type: 1 236 Length: Variable 237 0 1 2 3 238 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 1 239 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 240 | L1VPN TLV Type | L1VPN TLV Length | 241 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 242 | L1VPN Globally Unique Identifier | 243 | | 244 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 245 | PE TE Address | 246 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 247 | Link Local Identifier | 248 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 249 | ... | 250 | L1VPN Auto-Discovery Information | 251 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 252 | .| Padding | 253 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 255 L1VPN TLV Type 256 The type of the TLV. 258 TLV Length 259 The length of the TLV in bytes, excluding the four (4) bytes 260 of the TLV header and, if present, the length of the Padding 261 field. 263 L1VPN Globally Unique Identifier 264 As defined in [L1VPN-BM]. 266 PE TE Address 267 This field MUST carry an address that has been advertised by 268 the LSA originator per [RFC3630] and is either the Router Address 269 TLV or Local interface IP address link sub-TLV. It will 270 typically carry the TE Router Address. 272 Link Local Identifier 274 This field is used to support unnumbered links. When an 275 unnumbered PE TE link is represented, this field MUST contain 276 a value advertised by the LSA originator per [RFC4203] in a 277 Link Local/Remote Identifiers link sub-TLV. When a numbered 278 link is represented, this field MUST be set to zero (0). 280 L1VPN Auto-discovery information 281 As defined in [L1VPN-BM]. 283 Padding 284 A field of variable length and of sufficient size to ensure 285 that the TLV is aligned on a four (4) byte boundary. This 286 field is only required when the L1VPN Auto-discovery 287 information field is not four (4) byte aligned. This field 288 MUST be less than four (4) bytes long, and MUST NOT be present 289 when the size of L1VPN Auto-discovery information field is 290 four (4) byte aligned. 292 3. L1VPN LSA Advertising and Processing 294 PEs advertise local tuples in L1VPN LSAs containing L1VPN 295 Info TLVs. Each PE MUST originate a separate L1VPN LSA with AS 296 flooding scope for each local CE-PE link. The LSA MUST be originated 297 each time a PE restarts and every time there is a change in the PIT 298 entry associated with a local CE-PE link. The LSA MUST include a 299 single L1VPN Info TLV and MAY include a single TE Link TLV as per 300 [RFC3630] and [RFC4203]. The TE Link TLV carries TE attributes of 301 the associated CE-PE link. Note that because CEs are outside of the 302 provider TE domain, the attributes of CE-PE links are not advertised 303 via normal OSPF-TE procedures as described in [RFC3630] and 304 [RFC4203]. If more than one L1VPN Info TLVs and/or TE Link TLVs are 305 found in the LSA, the subsequent TLVs SHOULD be ignored by the 306 receiving PEs. 308 L1VPN LSAs are of AS-scope (LS type is set to 11) and therefor are 309 flooded to all PEs within the AS according to [RFC2370] or [2370BIS]. 310 Every time a PE receives a new, removed or modified L1VPN LSA, the PE 311 MUST check whether it maintains a PIT associated with the L1VPN 312 specified in the L1VPN Globally unique identifier field. If this is 313 the case (the appropriate PIT will be found if one or more local CE- 314 PE links that belong to the L1VPN are configured), the PE SHOULD add, 315 remove or modify the PIT entry associated with each of the advertised 316 CE-PE links accordingly. Thus, in the steady mode all PEs associated 317 with a particular L1VPN maintain identical local PITs for the L1VPN. 319 3.1. Discussion and Example 321 The L1VPN auto-discovery mechanism described in this document does 322 not prevent a PE from applying any local policy with respect to PIT 323 management. For example, it should be possible to configure permanent 324 (static) PIT entries, blocking of information carried in L1VPN LSAs 325 that are advertised by some remote PEs from making it to the PITs. 327 The reason why it is required that the value specified in the PE TE 328 Address field of the L1VPN Info TLV matches a valid PE TE Router ID 329 or numbered TE Link ID is to ensure that CEs attached to this PE can 330 be resolved to the PE as it is known to the Traffic Engineering 331 Database (TED) and hence TE paths toward the CEs across the Provider 332 domain can be computed. 334 Let us consider the example presented in Figure 2. 336 CE11 CE13 337 | | 338 CE22---PE1--------P------PE2 339 | | 340 CE15 PE3 341 | 342 CE24 344 Figure 2: Single area configuration 346 Let us assume that PE1 is connected to CE11 and CE15 in L1VPN1 and to 347 CE22 in L1VPN2; PE2 is connected to CE13 in L1VPN1; PE3 is connected 348 to CE24 in L1VPN2. In this configuration PE1 manages two PITs: PIT1 349 for L1VPN1 and PIT2 for L1VPN2; PE2 manages only PIT1, and PE3 350 manages only PIT2. PE1 originates three L1VPN LSAs, each containing a 351 L1VPN Info TLV advertising links PE1-CE11, PE1-CE22 and PE1-CE15 352 respectively. PE2 originates a single L1VPN LSA for link PE2-CE13 and 353 PE3 originates a single L1VPN LSA for link PE3-CE24. In steady state 354 the PIT1 on PE1 and PE3 will contain information on links PE1-CE11, 355 PE1-CE15 and PE2-CE13; PIT2 on PE1 and PE2 will contain entries for 356 links PE1-CE22 and PE3-CE24. Thus, all PEs will learn about all 357 remote PE-CE links for all L1VPNs supported by PEs. 359 Note that P in this configuration does not have links connecting it 360 to any of L1VPNs. It neither originates L1VPN LSAs nor maintains any 361 PITs. However, it does participate in the flooding of all of the 362 L1VPN LSA and hence maintains the LSAs in its LSDB. This is a cause 363 for scalability concerns and could prove to be problematic in large 364 networks. 366 4. Backward Compatibility 368 Neither the TLV nor the LSA introduced in this document present any 369 interoperability issues. Per [RFC2370], OSPF speakers that do not 370 support the L1VPN auto-discovery application (Ps for example) just 371 participate in the L1VPN LSAs flooding process but should ignore the 372 LSAs contents. 374 5. Security Considerations 376 The approach presented in this document describes how PEs dynamically 377 learn L1VPN specific information. Mechanisms to deliver the VPN 378 membership information to CEs are explicitly out of scope of this 379 document. Therefore, the security issues raised in this document are 380 limited to within the OSPF domain. 382 This defined approach reuses mechanisms defined in [RFC2328], 383 [RFC2370] and [2370BIS]. Therefore the same security approaches and 384 considerations apply to this approach. OSPF provides several 385 security mechanisms that can be applied. Specifically, OSPF supports 386 multiple types of authentication, limits the frequency of LSA 387 origination and acceptance, and provides techniques to avoid and 388 limit impact database overflow. In cases were end-to-end 389 authentication is desired, OSPF's neighbor-to-neighbor authentication 390 approach can be augmented with an experimental extension to OSPF, see 391 [RFC2154], which supports the signing and authentication of LSAs. 393 6. IANA Considerations 395 This document requests the assignment of an OSPF Opaque LSA type, see 396 http://www.iana.org/assignments/ospf-opaque-types. IANA is requested 397 to make an assignment in the form: 399 Value Opaque Type Reference 400 ------- ----------- --------- 401 TBA L1VPN LSA [this document] 403 A value of 4 is suggested for TBA. 405 7. Acknowledgment 407 We would like to thank Adrian Farrel and Anton Smirnov for their 408 useful comments. 410 8. References 412 8.1. Normative References 414 [RFC2119] Bradner, S., "Key words for use in RFCs to indicate 415 requirements levels", RFC 2119, March 1997. 417 [RFC2328] Moy, J., "OSPF Version 2 ", RFC 2328, April 1998. 419 [RFC2370] Coltun, R., "The OSPF Opaque LSA Option ", RFC 2730, 420 July 1998. 422 [RFC3630] Katz, D., Kompela, K., Yeung. D.., "Traffic Engineering 423 (TE) Extensions to OSPF Version 2", RFC 3630, September 424 2003. 426 [RFC4203] Kompela, K., Rekhter, Y. "OSPF Extensions in Support of 427 Generalized Multi-Protocol Label Switching (GMPLS)", RFC 428 4203, October 2005. 430 [L1VPN-BM] Fedyk, D., Rekhter, Y. (Eds.), "Layer 1 VPN Basic 431 Mode", draft-fedyk-l1vpn-basic-mode, March 432 2006, work in progress. 434 8.2. Informative References 436 [RFC2154] Murphy, S., Badger, M., Wellington, B., "OSPF with 437 Digital Signatures", RFC 2154, June 1997. 439 [2370BIS] Berger, L., Bryskin, I., Zinin, A., "The OSPF Opaque LSA 440 Option", work in progress, draft-ietf-ospf-rfc2370bis, 441 December, 2006. 443 [RFC4847] Tomonori Takeda, Ed., "Framework and Requirements 444 for Layer 1 Virtual Private Networks", RFC 4847, 445 April 2007. 447 [L1VPN-BGP] Ould-Brahim H., Fedyk D., Rekhter, Y., 448 "BGP-based Auto-Discovery for L1VPNs ", 449 draft-ouldbrahim-l1vpn-bgp-auto-discovery- 450 work in progress, March 2006 452 9. Authors' Addresses 454 Igor Bryskin 455 ADVA Optical Networking Inc 456 7926 Jones Branch Drive 457 Suite 615 458 McLean, VA - 22102 459 Email: ibryskin@advaoptical.com 461 Lou Berger 462 LabN Consulting, LLC 463 Email: lberger@labn.net 465 10. Full Copyright Statement 467 Copyright (C) The IETF Trust (2007). 469 This document is subject to the rights, licenses and restrictions 470 contained in BCP 78, and except as set forth therein, the authors 471 retain all their rights. 473 This document and the information contained herein are provided on an 474 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 475 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND 476 THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS 477 OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF 478 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 479 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 481 11. Intellectual Property 483 The IETF takes no position regarding the validity or scope of any 484 Intellectual Property Rights or other rights that might be claimed 485 to pertain to the implementation or use of the technology 486 described in this document or the extent to which any license 487 under such rights might or might not be available; nor does it 488 represent that it has made any independent effort to identify any 489 such rights. Information on the procedures with respect to rights 490 in RFC documents can be found in BCP 78 and BCP 79. 492 Copies of IPR disclosures made to the IETF Secretariat and any 493 assurances of licenses to be made available, or the result of an 494 attempt made to obtain a general license or permission for the use 495 of such proprietary rights by implementers or users of this 496 specification can be obtained from the IETF on-line IPR repository 497 at http://www.ietf.org/ipr. 499 The IETF invites any interested party to bring to its attention 500 any copyrights, patents or patent applications, or other 501 proprietary rights that may cover technology that may be required 502 to implement this standard. Please address the information to the 503 IETF at ietf-ipr@ietf.org. 505 Acknowledgement 507 Funding for the RFC Editor function is provided by the IETF 508 Administrative Support Activity (IASA). 510 Generated on: Mon Dec 3 19:01:42 EST 2007