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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Open Shortest Path First IGP P. Psenak, Ed. 3 Internet-Draft S. Previdi, Ed. 4 Intended status: Standards Track C. Filsfils 5 Expires: September 9, 2017 Cisco Systems, Inc. 6 H. Gredler 7 RtBrick Inc. 8 R. Shakir 9 Google, Inc. 10 W. Henderickx 11 Nokia 12 J. Tantsura 13 Individual 14 March 8, 2017 16 OSPFv3 Extensions for Segment Routing 17 draft-ietf-ospf-ospfv3-segment-routing-extensions-09 19 Abstract 21 Segment Routing (SR) allows for a flexible definition of end-to-end 22 paths within IGP topologies by encoding paths as sequences of 23 topological sub-paths, called "segments". These segments are 24 advertised by the link-state routing protocols (IS-IS and OSPF). 26 This draft describes the OSPFv3 extensions that are required for 27 Segment Routing. 29 Requirements Language 31 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 32 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 33 document are to be interpreted as described in RFC 2119 [RFC2119]. 35 Status of This Memo 37 This Internet-Draft is submitted in full conformance with the 38 provisions of BCP 78 and BCP 79. 40 Internet-Drafts are working documents of the Internet Engineering 41 Task Force (IETF). Note that other groups may also distribute 42 working documents as Internet-Drafts. The list of current Internet- 43 Drafts is at http://datatracker.ietf.org/drafts/current/. 45 Internet-Drafts are draft documents valid for a maximum of six months 46 and may be updated, replaced, or obsoleted by other documents at any 47 time. It is inappropriate to use Internet-Drafts as reference 48 material or to cite them other than as "work in progress." 49 This Internet-Draft will expire on September 9, 2017. 51 Copyright Notice 53 Copyright (c) 2017 IETF Trust and the persons identified as the 54 document authors. All rights reserved. 56 This document is subject to BCP 78 and the IETF Trust's Legal 57 Provisions Relating to IETF Documents 58 (http://trustee.ietf.org/license-info) in effect on the date of 59 publication of this document. Please review these documents 60 carefully, as they describe your rights and restrictions with respect 61 to this document. Code Components extracted from this document must 62 include Simplified BSD License text as described in Section 4.e of 63 the Trust Legal Provisions and are provided without warranty as 64 described in the Simplified BSD License. 66 Table of Contents 68 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 69 2. Segment Routing Identifiers . . . . . . . . . . . . . . . . . 3 70 2.1. SID/Label Sub-TLV . . . . . . . . . . . . . . . . . . . . 3 71 3. Segment Routing Capabilities . . . . . . . . . . . . . . . . 4 72 3.1. SR-Algorithm TLV . . . . . . . . . . . . . . . . . . . . 4 73 3.2. SID/Label Range TLV . . . . . . . . . . . . . . . . . . . 6 74 3.3. SR Local Block Sub-TLV . . . . . . . . . . . . . . . . . 7 75 3.4. SRMS Preference Sub-TLV . . . . . . . . . . . . . . . . . 9 76 3.5. SR-Forwarding Capabilities . . . . . . . . . . . . . . . 10 77 4. OSPFv3 Extended Prefix Range TLV . . . . . . . . . . . . . . 10 78 5. Prefix SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 12 79 6. SID/Label Binding Sub-TLV . . . . . . . . . . . . . . . . . . 16 80 6.1. ERO Metric Sub-TLV . . . . . . . . . . . . . . . . . . . 18 81 6.2. ERO Sub-TLVs . . . . . . . . . . . . . . . . . . . . . . 19 82 6.2.1. IPv4 ERO Sub-TLV . . . . . . . . . . . . . . . . . . 19 83 6.2.2. IPv6 ERO Sub-TLV . . . . . . . . . . . . . . . . . . 20 84 6.2.3. Unnumbered Interface ID ERO Sub-TLV . . . . . . . . . 21 85 6.2.4. IPv4 Backup ERO Sub-TLV . . . . . . . . . . . . . . . 22 86 6.2.5. IPv6 Backup ERO Sub-TLV . . . . . . . . . . . . . . . 23 87 6.2.6. Unnumbered Interface ID Backup ERO Sub-TLV . . . . . 24 88 7. Adjacency Segment Identifier (Adj-SID) . . . . . . . . . . . 25 89 7.1. Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 25 90 7.2. LAN Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . 27 91 8. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 29 92 8.1. Intra-area Segment routing in OSPFv3 . . . . . . . . . . 29 93 8.2. Inter-area Segment routing in OSPFv3 . . . . . . . . . . 30 94 8.3. SID for External Prefixes . . . . . . . . . . . . . . . . 31 95 8.4. Advertisement of Adj-SID . . . . . . . . . . . . . . . . 32 96 8.4.1. Advertisement of Adj-SID on Point-to-Point Links . . 32 97 8.4.2. Adjacency SID on Broadcast or NBMA Interfaces . . . . 32 98 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 99 9.1. OSPF Router Information (RI) TLVs Registry . . . . . . . 32 100 9.2. OSPFv3 Extend-LSA TLV Registry . . . . . . . . . . . . . 33 101 9.3. OSPFv3 Extend-LSA Sub-TLV registry . . . . . . . . . . . 33 102 10. Security Considerations . . . . . . . . . . . . . . . . . . . 33 103 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 33 104 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 34 105 12.1. Normative References . . . . . . . . . . . . . . . . . . 34 106 12.2. Informative References . . . . . . . . . . . . . . . . . 34 107 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 35 109 1. Introduction 111 Segment Routing (SR) allows for a flexible definition of end-to-end 112 paths within IGP topologies by encoding paths as sequences of 113 topological sub-paths, called "segments". These segments are 114 advertised by the link-state routing protocols (IS-IS and OSPF). 115 Prefix segments represent an ecmp-aware shortest-path to a prefix (or 116 a node), as per the state of the IGP topology. Adjacency segments 117 represent a hop over a specific adjacency between two nodes in the 118 IGP. A prefix segment is typically a multi-hop path while an 119 adjacency segment, in most of the cases, is a one-hop path. SR's 120 control-plane can be applied to both IPv6 and MPLS data-planes, and 121 does not require any additional signaling (other than the regular 122 IGP). For example, when used in MPLS networks, SR paths do not 123 require any LDP or RSVP-TE signaling. Still, SR can interoperate in 124 the presence of LSPs established with RSVP or LDP. 126 This draft describes the OSPFv3 extensions required for segment 127 routing. 129 Segment Routing architecture is described in 130 [I-D.ietf-spring-segment-routing]. 132 Segment Routing use cases are described in 133 [I-D.filsfils-spring-segment-routing-use-cases]. 135 2. Segment Routing Identifiers 137 Segment Routing defines various types of Segment Identifiers (SIDs): 138 Prefix-SID, Adjacency-SID, LAN Adjacency SID and Binding SID. 140 2.1. SID/Label Sub-TLV 142 The SID/Label Sub-TLV appears in multiple TLVs or Sub-TLVs defined 143 later in this document. It is used to advertise the SID or label 144 associated with a prefix or adjacency. The SID/Label TLV has 145 following format: 147 0 1 2 3 148 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 1 149 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 150 | Type | Length | 151 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 152 | SID/Label (variable) | 153 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 155 where: 157 Type: TBD, suggested value 3 159 Length: variable, 3 or 4 bytes 161 SID/Label: if length is set to 3, then the 20 rightmost bits 162 represent a label. If length is set to 4, then the value 163 represents a 32 bit SID. 165 The receiving router MUST ignore the SID/Label Sub-TLV if the 166 length is other then 3 or 4. 168 3. Segment Routing Capabilities 170 Segment Routing requires some additional capabilities of the router 171 to be advertised to other routers in the area. 173 These SR capabilities are advertised in OSPFv3 Router Information LSA 174 (defined in [RFC4970]). 176 3.1. SR-Algorithm TLV 178 The SR-Algorithm TLV is a TLV of the OSPFv3 Router Information LSA 179 (defined in [RFC4970]). 181 The SR-Algorithm TLV is optional. It MAY only be advertised once in 182 the OSPFv3 Router Information LSA. If the SID/Label Range TLV, as 183 defined in Section 3.2, is advertised, then the SR-Algorithm TLV MUST 184 also be advertised. If the SR-Algorithm TLV is not advertised by the 185 node, such node is considered as not being segment routing capable. 187 An OSPFv3 router may use various algorithms when calculating 188 reachability to other nodes in area or to prefixes attached to these 189 nodes. Examples of these algorithms are metric based Shortest Path 190 First (SPF), various sorts of Constrained SPF, etc. The SR-Algorithm 191 TLV allows a router to advertise the algorithms that the router is 192 currently using to other routers in an area. The SR-Algorithm TLV 193 has following structure: 195 0 1 2 3 196 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 1 197 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 198 | Type | Length | 199 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 200 | Algorithm 1 | Algorithm... | Algorithm n | | 201 +- -+ 202 | | 203 + + 205 where: 207 Type: TBD, suggested value 8 209 Length: variable 211 Algorithm: Single octet identifying the algorithm. The following 212 value has been defined: 214 0: Shortest Path First (SPF) algorithm based on link metric. 215 This is the standard shortest path algorithm as computed by the 216 OSPF protocol. Consistent with the deployed practice for link- 217 state protocols, Algorithm 0 permits any node to overwrite the 218 SPF path with a different path based on its local policy. If 219 the SR-Algorithm Sub-TLV is advertised, Algorithm 0 MUST be 220 included. 222 1: Strict Shortest Path First (SPF) algorithm based on link 223 metric. The algorithm is identical to Algorithm 0 but 224 Algorithm 1 requires that all nodes along the path will honor 225 the SPF routing decision. Local policy at the node claiming 226 the support of Algorithm 1 MUST NOT alter the forwarding 227 decision computed by Algorithm 1. 229 When multiple SR-Algorithm sub-TLVs are received from a given router 230 the receiver SHOULD use the first occurrence of the sub-TLV in the 231 OSPFv3 Router Information LSA. If the SR-Algorithm sub-TLV appears 232 in multiple OSPFv3 Router Information LSAs that have different 233 flooding scopes, the SR-Algorithm sub-TLV in the OSPFv3 Router 234 Information LSA with the lowest flooding scope SHOULD be used. If 235 the SR-Algorithm sub-TLV appears in multiple OSPFv3 Router 236 Information LSAs that have the same flooding scope, the SR-Algorithm 237 sub-TLV in the OSPFv3 Router Information LSA with the numerically 238 smallest Instance ID SHOULD be used and subsequent instances of the 239 SR-Algorithm sub-TLV SHOULD be ignored. 241 The RI LSA can be advertised at any of the defined flooding scopes 242 (link, area, or autonomous system (AS)). For the purpose of the SR- 243 Algorithm TLV propagation, area scope flooding is required. 245 3.2. SID/Label Range TLV 247 The SID/Label Range TLV is a TLV of the OSPFv3 Router Information LSA 248 (defined in [RFC4970]). 250 The SID/Label Sub-TLV MAY appear multiple times and has following 251 format: 253 0 1 2 3 254 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 1 255 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 256 | Type | Length | 257 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 258 | Range Size | Reserved | 259 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 260 | Sub-TLVs (variable) | 261 +- -+ 262 | | 263 + + 265 where: 267 Type: TBD, suggested value 9 269 Length: variable 271 Range Size: 3 octets of SID/label range 273 Initially, the only supported Sub-TLV is the SID/Label TLV as defined 274 in Section 2.1. The SID/Label advertised in the SID/Label TLV 275 represents the first SID/Label in the advertised range. 277 Multiple occurrence of the SID/Label Range TLV MAY be advertised, in 278 order to advertise multiple ranges. In such case: 280 o The originating router MUST encode each range into a different 281 SID/Label Range TLV. 283 o The originating router decides the order in which the set of SID/ 284 Label Range TLVs are advertised in the OSPFv3 Router Information 285 LSA. The originating router MUST ensure the order is same after a 286 graceful restart (using checkpointing, non-volatile storage or any 287 other mechanism) in order to assure the SID/label range and SID 288 index correspondence is preserved across graceful restarts. 290 o The receiving router must adhere to the order in which the ranges 291 are advertised when calculating a SID/label from the SID index. 293 o A router not supporting multiple occurrences of the SID/Label 294 Range TLV MUST use first advertised SID/Label Range TLV. 296 The following example illustrates the advertisement of multiple 297 ranges: 299 The originating router advertises the following ranges: 300 Range 1: [100, 199] 301 Range 2: [1000, 1099] 302 Range 3: [500, 599] 304 The receiving routers concatenate the ranges and build the Segment Routing Global Block 305 (SRGB) is as follows: 307 SRGB = [100, 199] 308 [1000, 1099] 309 [500, 599] 311 The indexes span multiple ranges: 313 index=0 means label 100 314 ... 315 index 99 means label 199 316 index 100 means label 1000 317 index 199 means label 1099 318 ... 319 index 200 means label 500 320 ... 322 The RI LSA can be advertised at any of the defined flooding scopes 323 (link, area, or autonomous system (AS)). For the purpose of the SID/ 324 Label Range TLV propagation, area scope flooding is required. 326 3.3. SR Local Block Sub-TLV 328 The SR Local Block (SRLB) Sub-TLV contains the range of labels the 329 node has reserved for local SIDs. Local SIDs are used, e.g., for 330 Adjacency-SIDs, and may also be allocated by other components than 331 OSPF protocol. As an example, an application or a controller may 332 instruct the router to allocate a specific local SID. Therefore, in 333 order for such applications or controllers to know what are the local 334 SIDs available in the router, it is required that the router 335 advertises its SRLB. The SRLB Sub-TLV is used for that purpose. 337 The SR Local Block (SRLB) Sub-TLV is a top-level TLV of the OSPFv3 338 Router Information Opaque LSA (defined in [RFC7770]). 340 The SR Local Block Sub-TLV MAY appear multiple times in the OSPFv3 341 Router Information Opaque LSA and has the following format: 343 0 1 2 3 344 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 1 345 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 346 | Type | Length | 347 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 348 | Range Size | Reserved | 349 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 350 | Sub-TLVs (variable) | 351 +- -+ 352 | | 353 + + 355 where: 357 Type: TBD, suggested value 12 359 Length: variable 361 Range Size: 3 octets of the SID/label range. MUST be higher then 362 0. 364 Initially, the only supported Sub-TLV is the SID/Label TLV as defined 365 in Section 2.1. The SID/Label advertised in the SID/Label TLV 366 represents the first SID/Label in the advertised range. 368 When multiple SRLB sub-TLVs are received from a given router the 369 behavior of the receiving system is undefined. 371 The originating router MUST NOT advertise overlapping ranges. 373 Each time a SID from the SRLB is allocated, it SHOULD also be 374 reported to all components (e.g.: controller or applications) in 375 order for these components to have an up-to-date view of the current 376 SRLB allocation. This is required to avoid collision between 377 allocation instructions. 379 Within the context of OSPFv3, the reporting of local SIDs is done 380 through OSPF Sub-TLVs such as the Adjacency-SID (Section 7). 381 However, the reporting of allocated local SIDs may also be done 382 through other means and protocols which mechanisms are outside the 383 scope of this document. 385 A router advertising the SRLB TLV may also have other label ranges, 386 outside of the SRLB, used for its local allocation purposes which are 387 NOT advertised in the SRLB. For example, it is possible that an 388 Adjacency-SID is allocated using a local label that is not part of 389 the SRLB. 391 The OSPFv3 RI LSA can be advertised at any of the defined flooding 392 scopes (link, area, or autonomous system (AS)). For the purpose of 393 SR Local Block Sub-TLV TLV advertisement, area scope flooding is 394 required. 396 3.4. SRMS Preference Sub-TLV 398 The Segment Routing Mapping Server (SRMS) Preference sub-TLV is used 399 to advertise a preference associated with the node that acts as a SR 400 Mapping Server. SRMS preference is defined in 401 [I-D.ietf-spring-conflict-resolution]. 403 The SRMS Preference Sub-TLV is a top-level TLV of the OSPFv3 Router 404 Information Opaque LSA (defined in [RFC7770]). 406 The SRMS Preference Sub-TLV MAY only be advertised once in the OSPFv3 407 Router Information Opaque LSA and has the following format: 409 0 1 2 3 410 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 1 411 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 412 | Type | Length | 413 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 414 | Preference | Reserved | 415 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 417 where: 419 Type: TBD, suggested value 13 421 Length: 4 octets 423 Preference: 1 octet. SRMS preference value from 0 to 255. 425 When multiple SRMS Preference sub-TLVs are received from a given 426 router the receiver SHOULD use the first occurrence of the sub-TLV in 427 the OSPFv3 Router Information LSA. If the SRMS Preference sub-TLV 428 appears in multiple OSPFv3 Router Information LSAs that have 429 different flooding scopes, the SRLB sub-TLV in the OSPFv3 Router 430 Information LSA with the lowest flooding scope SHOULD be used. If 431 the SRMS Preference sub-TLV appears in multiple OSPFv3 Router 432 Information LSAs that have the same flooding scope, the SRMS 433 Preference sub-TLV in the OSPFv3 Router Information LSA with the 434 numerically smallest Instance ID SHOULD be used and subsequent 435 instances of the SRMS Preference sub-TLV SHOULD be ignored. 437 The OSPFv3 RI LSA can be advertised at any of the defined flooding 438 scopes (link, area, or autonomous system (AS)). For the purpose of 439 the SRMS Preference Sub-TLV advertisement, AS scope flooding is 440 required. If the SRMS advertisements from the SRMS server are only 441 used inside the area to which the SRMS server is attached, area scope 442 flooding may be used. 444 3.5. SR-Forwarding Capabilities 446 OSPFv3 router supporting Segment Routing needs to advertise its SR 447 data-plane capabilities. Data-plane capabilities are advertised in 448 OSPF Router Informational Capabilities TLV, which is defined in 449 section 2.3 of RFC 4970 [RFC4970]. 451 Two new bits are allocated in the OSPF Router Informational 452 Capability Bits as follows: 454 Bit-6 - MPLS IPv6 flag. If set, then the router is capable of 455 processing SR MPLS encapsulated IPv6 packets on all interfaces. 457 Bit-7 - If set, then the router is capable of processing the IPv6 458 Segment Routing Header on all interfaces as defined in 459 [I-D.previdi-6man-segment-routing-header]. 461 For the purpose of the SR-Forwarding Capabilities propagation, area 462 scope flooding is required. 464 4. OSPFv3 Extended Prefix Range TLV 466 In some cases it is useful to advertise attributes for a range of 467 prefixes. Segment Routing Mapping Server, which is described in 468 [I-D.filsfils-spring-segment-routing-ldp-interop], is an example 469 where we need a single advertisement to advertise SIDs for multiple 470 prefixes from a contiguous address range. The OSPFv3 Extended Prefix 471 Range TLV is defined for this purpose. 473 The OSPFv3 Extended Prefix Range TLV is a new top level TLV of the 474 following LSAs defined in [I-D.ietf-ospf-ospfv3-lsa-extend]: 476 E-Intra-Area-Prefix-LSA 478 E-Inter-Area-Prefix-LSA 480 E-AS-External-LSA 481 E-Type-7-LSA 483 Multiple OSPFv3 Extended Prefix Range TLVs MAY be advertised in these 484 extended LSAs. The OSPFv3 Extended Prefix Range TLV has the 485 following format: 487 0 1 2 3 488 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 1 489 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 490 | Type | Length | 491 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 492 | Prefix Length | AF | Range Size | 493 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 494 | Flags | Reserved | 495 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 496 | Address Prefix (variable) | 497 | ... | 498 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 499 | Sub-TLVs (variable) | 500 +- -+ 501 | | 503 where: 505 Type: TBD, suggested value 9. 507 Length: variable 509 Prefix length: length of the prefix 511 AF: 0 - IPv6 unicast 513 Range size: represents the number of prefixes that are covered by 514 the advertisement. The Range Size MUST NOT exceed the number of 515 prefixes that could be satisfied by the prefix length without 516 including addresses from other than the IPv6 unicast address 517 class. 519 Flags: 1 octet field. The following flags are defined: 521 0 1 2 3 4 5 6 7 522 +--+--+--+--+--+--+--+--+ 523 |IA| | | | | | | | 524 +--+--+--+--+--+--+--+--+ 526 where: 528 IA-Flag: Inter-Area flag. If set, advertisement is of inter- 529 area type. ABR that is advertising the OSPF Extended Prefix 530 Range TLV between areas MUST set this bit. 532 This bit is used to prevent redundant flooding of Prefix Range 533 TLVs between areas as follows: 535 An ABR always prefers intra-area Prefix Range advertisement 536 over inter-area one. 538 An ABR does not consider inter-area Prefix Range 539 advertisements coming from non backbone area. 541 An ABR propagates inter-area Prefix Range advertisement from 542 backbone area to connected non backbone areas only if such 543 advertisement is considered to be the best one. 545 Address Prefix: the prefix, encoded as an even multiple of 32-bit 546 words, padded with zeroed bits as necessary. This encoding 547 consumes ((PrefixLength + 31) / 32) 32-bit words. The Address 548 Prefix represents the first prefix in the prefix range. 550 5. Prefix SID Sub-TLV 552 The Prefix SID Sub-TLV is a Sub-TLV of the following OSPFv3 TLVs as 553 defined in [I-D.ietf-ospf-ospfv3-lsa-extend] and in Section 4: 555 Intra-Area Prefix TLV 557 Inter-Area Prefix TLV 559 External Prefix TLV 561 OSPFv3 Extended Prefix Range TLV 563 It MAY appear more than once in the parent TLV and has the following 564 format: 566 0 1 2 3 567 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 1 568 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 569 | Type | Length | 570 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 571 | Flags | Algorithm | Reserved | 572 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 573 | SID/Index/Label (variable) | 574 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 576 where: 578 Type: TBD, suggested value 4. 580 Length: variable 582 Flags: 1 octet field. The following flags are defined: 584 0 1 2 3 4 5 6 7 585 +--+--+--+--+--+--+--+--+ 586 | |NP|M |E |V |L | | | 587 +--+--+--+--+--+--+--+--+ 589 where: 591 NP-Flag: No-PHP flag. If set, then the penultimate hop MUST 592 NOT pop the Prefix-SID before delivering the packet to the node 593 that advertised the Prefix-SID. 595 M-Flag: Mapping Server Flag. If set, the SID is advertised 596 from the Segment Routing Mapping Server functionality as 597 described in [I-D.filsfils-spring-segment-routing-ldp-interop]. 599 E-Flag: Explicit-Null Flag. If set, any upstream neighbor of 600 the Prefix-SID originator MUST replace the Prefix-SID with a 601 Prefix-SID having an Explicit-NULL value (0 for IPv4) before 602 forwarding the packet. 604 The V-Flag: Value/Index Flag. If set, then the Prefix-SID 605 carries an absolute value. If not set, then the Prefix-SID 606 carries an index. 608 The L-Flag: Local/Global Flag. If set, then the value/index 609 carried by the Prefix-SID has local significance. If not set, 610 then the value/index carried by this Sub-TLV has global 611 significance. 613 Other bits: Reserved. These MUST be zero when sent and are 614 ignored when received. 616 Algorithm: one octet identifying the algorithm the Prefix-SID is 617 associated with as defined in Section 3.1. 619 A router receiving a Prefix-SID from a remote node and with an 620 algorithm value that such remote node has not advertised in the 621 SR-Algorithm sub-TLV (Section 3.1) MUST ignore the Prefix-SID sub- 622 TLV. 624 SID/Index/Label: label or index value depending on the V-bit 625 setting. 627 Examples: 629 A 32 bit global index defining the offset in the SID/Label 630 space advertised by this router - in this case the V and L 631 flags MUST NOT be set. 633 A 24 bit local label where the 20 rightmost bits are used 634 for encoding the label value - in this case the V and L 635 flags MUST be set. 637 If multiple Prefix-SIDs are advertised for the same prefix, the 638 receiving router MUST use the first encoded SID and MAY use the 639 subsequent SIDs. 641 When propagating Prefix-SIDs between areas, if multiple prefix-SIDs 642 are advertised for a prefix, an implementation SHOULD preserve the 643 original order when advertising prefix-SIDs to other areas. This 644 allows implementations that only support a single Prefix-SID to have 645 a consistent view across areas. 647 When calculating the outgoing label for the prefix, the router MUST 648 take into account E and P flags advertised by the next-hop router, if 649 next-hop router advertised the SID for the prefix. This MUST be done 650 regardless of whether the next-hop router contributes to the best 651 path to the prefix. 653 The NP-Flag (No-PHP) MUST be set for Prefix-SIDs allocated to inter- 654 area prefixes that are originated by the ABR based on intra-area or 655 inter-area reachability between areas. When the inter-area prefix is 656 generated based on a prefix which is directly attached to the ABR, 657 NP-Flag SHOULD NOT be set 658 The NP-Flag (No-PHP) MUST be set on the Prefix-SIDs allocated to 659 redistributed prefixes, unless the redistributed prefix is directly 660 attached to ASBR, in which case the NP-Flag SHOULD NOT be set. 662 If the NP-Flag is not set then any upstream neighbor of the Prefix- 663 SID originator MUST pop the Prefix-SID. This is equivalent to the 664 penultimate hop popping mechanism used in the MPLS dataplane. In 665 such case, MPLS EXP bits of the Prefix-SID are not preserved for the 666 final destination (the Prefix-SID being removed). If the NP-Flag is 667 clear then the received E-flag is ignored. 669 If the NP-Flag is set then: 671 If the E-flag is not set then any upstream neighbor of the Prefix- 672 SID originator MUST keep the Prefix-SID on top of the stack. This 673 is useful when the originator of the Prefix-SID must stitch the 674 incoming packet into a continuing MPLS LSP to the final 675 destination. This could occur at an inter-area border router 676 (prefix propagation from one area to another) or at an inter- 677 domain border router (prefix propagation from one domain to 678 another). 680 If the E-flag is set then any upstream neighbor of the Prefix-SID 681 originator MUST replace the Prefix-SID with a Prefix-SID having an 682 Explicit-NULL value. This is useful, e.g., when the originator of 683 the Prefix-SID is the final destination for the related prefix and 684 the originator wishes to receive the packet with the original EXP 685 bits. 687 When M-Flag is set, NP-flag and E-flag MUST be ignored at reception. 689 As the Mapping Server does not specify the originator of a prefix 690 advertisement it is not possible to determine PHP behavior solely 691 based on the Mapping Server advertisement. However, PHP behavior may 692 safely be done in following cases: 694 Prefix is of intra-area type and the downstream neighbor is the 695 originator of the prefix. 697 Prefix is of inter-area type and downstream neighbor is an ABR, 698 which is advertising the prefix reachability and is setting LA-bit 699 in the Prefix Options as described in section 3.1 of 700 [I-D.ietf-ospf-ospfv3-lsa-extend]. 702 Prefix is of external type and downstream neighbor is an ASBR, 703 which is advertising the prefix reachability and is setting LA-bit 704 in the Prefix Options as described in section 3.1 of 705 [I-D.ietf-ospf-ospfv3-lsa-extend]. 707 When a Prefix-SID is advertised in an Extended Prefix Range TLV, then 708 the value advertised in Prefix SID Sub-TLV is interpreted as a 709 starting SID value. 711 Example 1: if the following router addresses (loopback addresses) 712 need to be mapped into the corresponding Prefix SID indexes: 714 Router-A: 192::1/128, Prefix-SID: Index 1 715 Router-B: 192::2/128, Prefix-SID: Index 2 716 Router-C: 192::3/128, Prefix-SID: Index 3 717 Router-D: 192::4/128, Prefix-SID: Index 4 719 then the Address Prefix field in the OSPFv3 Extended Prefix Range TLV 720 is set to 192::1, Prefix Length would be set to 128, Range Size would 721 be set to 4 and the Index value in the Prefix-SID Sub-TLV would be 722 set to 1. 724 Example 2: If the following prefixes need to be mapped into the 725 corresponding Prefix-SID indexes: 727 10:1:1::0/120, Prefix-SID: Index 51 728 10:1:1::100/120, Prefix-SID: Index 52 729 10:1:1::200/120, Prefix-SID: Index 53 730 10:1:1::300/120, Prefix-SID: Index 54 731 10:1:1::400/120, Prefix-SID: Index 55 732 10:1:1::500/120, Prefix-SID: Index 56 733 10:1:1::600/120, Prefix-SID: Index 57 735 then the Address Prefix field in the OSPFv3 Extended Prefix Range TLV 736 is set to 10:1:1::0, Prefix Length would be set to 120, Range Size 737 would be set to 7 and the Index value in the Prefix-SID Sub-TLV would 738 be set to 51. 740 6. SID/Label Binding Sub-TLV 742 The SID/Label Binding Sub-TLV is used to advertise SID/Label mapping 743 for a path to the prefix. 745 The SID/Label Binding Sub-TLV MAY be originated by any router in an 746 OSPFv3 domain. The router may advertise a SID/Label binding to a FEC 747 along with at least a single 'nexthop style' anchor. The protocol 748 supports more than one 'nexthop style' anchor to be attached to a 749 SID/Label binding, which results into a simple path description 750 language. In analogy to RSVP the terminology for this is called an 751 'Explicit Route Object' (ERO). Since ERO style path notation allows 752 anchoring SID/label bindings to both link and node IP addresses, any 753 Label Switched Path (LSP) can be described. Furthermore, SID/Label 754 Bindings from external protocols can also be re-advertised. 756 The SID/Label Binding Sub-TLV may be used for advertising SID/Label 757 Bindings and their associated Primary and Backup paths. In one 758 single TLV, either a primary ERO Path, backup ERO Path, or both are 759 advertised. If a router wants to advertise multiple parallel paths, 760 then it can generate several TLVs for the same Prefix/FEC. Each 761 occurrence of a Binding TLV for a given FEC Prefix will add a new 762 path. 764 SID/Label Binding Sub-TLV is a Sub-TLV of the following OSPFv3 TLVs, 765 as defined in [I-D.ietf-ospf-ospfv3-lsa-extend] and in Section 4: 767 Intra-Area Prefix TLV 769 Inter-Area Prefix TLV 771 External Prefix TLV 773 OSPFv3 Extended Prefix Range TLV 775 Multiple SID/Label Binding Sub-TLVs can be present in these TLVs. 776 The SID/Label Binding Sub-TLV has following format: 778 0 1 2 3 779 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 1 780 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 781 | Type | Length | 782 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 783 | Flags | Weight | Reserved | 784 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 785 | Sub-TLVs (variable) | 786 +- -+ 787 | | 789 where: 791 Type: TBD, suggested value 7 793 Length: variable 795 Flags: 1 octet field of following flags: 797 0 1 2 3 4 5 6 7 798 +-+-+-+-+-+-+-+-+ 799 |M| | 800 +-+-+-+-+-+-+-+-+ 802 where: 804 M-bit - When the bit is set the binding represents the 805 mirroring context as defined in 806 [I-D.minto-rsvp-lsp-egress-fast-protection]. 808 Weight: weight used for load-balancing purposes. The use of the 809 weight is defined in section 3.5.1 of 810 [I-D.ietf-spring-segment-routing]. 812 SID/Label Binding Sub-TLV currently supports following Sub-TLVs: 814 SID/Label Sub-TLV as described in Section 2.1. This Sub-TLV MUST 815 appear in the SID/Label Binding Sub-TLV and it MUST only appear 816 once. 818 ERO Metric Sub-TLV as defined in Section 6.1. 820 ERO Sub-TLVs as defined in Section 6.2. 822 6.1. ERO Metric Sub-TLV 824 The ERO Metric Sub-TLV is a Sub-TLV of the SID/Label Binding Sub-TLV. 826 The ERO Metric Sub-TLV advertises the cost of an ERO path. It is 827 used to compare the cost of a given source/destination path. A 828 router SHOULD advertise the ERO Metric Sub-TLV in an advertised ERO 829 TLV. The cost of the ERO Metric Sub-TLV SHOULD be set to the 830 cumulative IGP or TE path cost of the advertised ERO. Since 831 manipulation of the Metric field may attract or repel traffic to and 832 from the advertised segment, it MAY be manually overridden. 834 0 1 2 3 835 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 1 836 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 837 | Type | Length | 838 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 839 | Metric (4 octets) | 840 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 842 ERO Metric Sub-TLV format 844 where: 846 Type: TBD, suggested value 8 848 Length: Always 4 850 Metric: A 4 octet metric representing the aggregate IGP or TE path 851 cost. 853 6.2. ERO Sub-TLVs 855 All 'ERO' information represents an ordered set which describes the 856 segments of a path. The first ERO Sub-TLV describes the first 857 segment of a path. Similiarly, the last ERO Sub-TLV describes the 858 segment closest to the egress point. If a router extends or stitches 859 a path, it MUST prepend the new segment's path information to the ERO 860 list. This applies equally to advertised backup EROs. 862 All ERO Sub-TLVs must immediately follow the (SID)/Label Sub-TLV. 864 All Backup ERO Sub-TLVs must immediately follow the last ERO Sub-TLV. 866 6.2.1. IPv4 ERO Sub-TLV 868 IPv4 ERO Sub-TLV is a Sub-TLV of the SID/Label Binding Sub-TLV. 870 The IPv4 ERO Sub-TLV describes a path segment using IPv4 Address 871 style of encoding. Its semantics have been borrowed from [RFC3209]. 873 0 1 2 3 874 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 1 875 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 876 | Type | Length | 877 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 878 | Flags | Reserved | 879 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 880 | IPv4 Address (4 octets) | 881 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 883 IPv4 ERO Sub-TLV format 885 where: 887 Type: TBD, suggested value 9 889 Length: 8 bytes 891 Flags: 1 octet field of following flags: 893 0 1 2 3 4 5 6 7 894 +-+-+-+-+-+-+-+-+ 895 |L| | 896 +-+-+-+-+-+-+-+-+ 898 where: 900 L-bit - If the L-bit is set, then the segment path is 901 designated as 'loose'. Otherwise, the segment path is 902 designated as 'strict'. 904 IPv4 Address - the address of the explicit route hop. 906 6.2.2. IPv6 ERO Sub-TLV 908 IPv6 ERO Sub-TLV is a Sub-TLV of the SID/Label Binding Sub-TLV. 910 The IPv6 ERO Sub-TLV (Type TBA) describes a path segment using IPv6 911 Address style of encoding. Its semantics have been borrowed from 912 [RFC3209]. 914 0 1 2 3 915 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 1 916 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 917 | Type | Length | 918 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 919 | Flags | Reserved | 920 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 921 | | 922 +- -+ 923 | | 924 +- IPv6 Address -+ 925 | | 926 +- -+ 927 | | 928 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 930 IPv6 ERO Sub-TLV format 932 where: 934 Type: TBD, suggested value 10 936 Length: 8 bytes 938 Flags: 1 octet field of following flags: 940 0 1 2 3 4 5 6 7 941 +-+-+-+-+-+-+-+-+ 942 |L| | 943 +-+-+-+-+-+-+-+-+ 945 where: 947 L-bit - If the L-bit is set, then the segment path is 948 designated as 'loose'. Otherwise, the segment path is 949 designated as 'strict'. 951 IPv6 Address - the address of the explicit route hop. 953 6.2.3. Unnumbered Interface ID ERO Sub-TLV 955 The Unnumbered Interface ID ERO Sub-TLV is a Sub-TLV of the SID/Label 956 Binding Sub-TLV. 958 The appearance and semantics of the 'Unnumbered Interface ID' have 959 been borrowed from [RFC3477]. 961 The Unnumbered Interface-ID ERO Sub-TLV describes a path segment that 962 spans over an unnumbered interface. Unnumbered interfaces are 963 referenced using the interface index. Interface indices are assigned 964 local to the router and therefore not unique within a domain. All 965 elements in an ERO path need to be unique within a domain and hence 966 need to be disambiguated using a domain unique Router-ID. 968 0 1 2 3 969 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 1 970 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 971 | Type | Length | 972 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 973 | Flags | Reserved | 974 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 975 | Router ID | 976 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 977 | Interface ID | 978 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 980 where: 982 Unnumbered Interface ID ERO Sub-TLV format 984 Type: TBD, suggested value 11 986 Length: 12 bytes 988 Flags: 1 octet field of following flags: 990 0 1 2 3 4 5 6 7 991 +-+-+-+-+-+-+-+-+ 992 |L| | 993 +-+-+-+-+-+-+-+-+ 995 where: 997 L-bit - If the L-bit is set, then the segment path is 998 designated as 'loose'. Otherwise, the segment path is 999 designated as 'strict'. 1001 Router-ID: Router-ID of the next-hop. 1003 Interface ID: is the identifier assigned to the link by the router 1004 specified by the Router-ID. 1006 6.2.4. IPv4 Backup ERO Sub-TLV 1008 IPv4 Prefix Backup ERO Sub-TLV is a Sub-TLV of the SID/Label Binding 1009 Sub-TLV. 1011 The IPv4 Backup ERO Sub-TLV describes a path segment using IPv4 1012 Address style of encoding. Its semantics have been borrowed from 1013 [RFC3209]. 1015 0 1 2 3 1016 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 1017 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1018 | Type | Length | 1019 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1020 | Flags | Reserved | 1021 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1022 | IPv4 Address (4 octets) | 1023 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1025 IPv4 Backup ERO Sub-TLV format 1027 where: 1029 Type: TBD, suggested value 12 1031 Length: 8 bytes 1033 Flags: 1 octet field of following flags: 1035 0 1 2 3 4 5 6 7 1036 +-+-+-+-+-+-+-+-+ 1037 |L| | 1038 +-+-+-+-+-+-+-+-+ 1040 where: 1042 L-bit - If the L-bit is set, then the segment path is 1043 designated as 'loose'. Otherwise, the segment path is 1044 designated as 'strict'.' 1046 IPv4 Address - the address of the explicit route hop. 1048 6.2.5. IPv6 Backup ERO Sub-TLV 1050 The IPv6 ERO Sub-TLV is a Sub-TLV of the SID/Label Binding Sub-TLV. 1052 The IPv6 Backup ERO Sub-TLV describes a Backup path segment using 1053 IPv6 Address style of encoding. Its appearance and semantics have 1054 been borrowed from [RFC3209]. 1056 The 'L' bit in the Flags is a one-bit attribute. If the L bit is 1057 set, then the value of the attribute is 'loose.' Otherwise, the 1058 value of the attribute is 'strict.' 1060 0 1 2 3 1061 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 1062 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1063 | Type | Length | 1064 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1065 | Flags | Reserved | 1066 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1067 | | 1068 +- -+ 1069 | | 1070 +- IPv6 Address -+ 1071 | | 1072 +- -+ 1073 | | 1074 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1076 IPv6 Backup ERO Sub-TLV format 1078 where: 1080 Type: TBD, suggested value 13 1082 Length: 8 bytes 1083 Flags: 1 octet field of following flags: 1085 0 1 2 3 4 5 6 7 1086 +-+-+-+-+-+-+-+-+ 1087 |L| | 1088 +-+-+-+-+-+-+-+-+ 1090 where: 1092 L-bit - If the L-bit is set, then the segment path is 1093 designated as 'loose'. Otherwise, the segment path is 1094 designated as 'strict'. 1096 IPv6 Address - the address of the explicit route hop. 1098 6.2.6. Unnumbered Interface ID Backup ERO Sub-TLV 1100 The Unnumbered Interface ID Backup Sub-TLV is a Sub-TLV of the SID/ 1101 Label Binding Sub-TLV. 1103 The appearance and semantics of the 'Unnumbered Interface ID' have 1104 been borrowed from [RFC3477]. 1106 The Unnumbered Interface-ID Backup ERO Sub-TLV describes a path 1107 segment that spans over an unnumbered interface. Unnumbered 1108 interfaces are referenced using the interface index. Interface 1109 indices are assigned local to the router and are therefore not unique 1110 within a domain. All elements in an ERO path need to be unique 1111 within a domain and hence need to be disambiguated with specification 1112 of the unique Router-ID. 1114 0 1 2 3 1115 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 1116 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1117 | Type | Length | 1118 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1119 | Flags | Reserved | 1120 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1121 | Router ID | 1122 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1123 | Interface ID | 1124 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1126 Unnumbered Interface ID Backup ERO Sub-TLV format 1128 where: 1130 Type: TBD, suggested value 14 1131 Length: 12 bytes 1133 Flags: 1 octet field of following flags: 1135 0 1 2 3 4 5 6 7 1136 +-+-+-+-+-+-+-+-+ 1137 |L| | 1138 +-+-+-+-+-+-+-+-+ 1140 where: 1142 L-bit - If the L-bit is set, then the segment path is 1143 designated as 'loose'. Otherwise, the segment path is 1144 designated as 'strict'. 1146 Router-ID: Router-ID of the next-hop. 1148 Interface ID: is the identifier assigned to the link by the router 1149 specified by the Router-ID. 1151 7. Adjacency Segment Identifier (Adj-SID) 1153 An Adjacency Segment Identifier (Adj-SID) represents a router 1154 adjacency in Segment Routing. 1156 7.1. Adj-SID Sub-TLV 1158 The extended OSPFv3 LSAs, as defined in 1159 [I-D.ietf-ospf-ospfv3-lsa-extend], are used to advertise prefix SID 1160 in OSPFv3 1162 The Adj-SID Sub-TLV is an optional Sub-TLV of the Router-Link TLV as 1163 defined in [I-D.ietf-ospf-ospfv3-lsa-extend]. It MAY appear multiple 1164 times in Router-Link TLV. Examples where more than one Adj-SID may 1165 be used per neighbor are described in section 4 of 1166 [I-D.filsfils-spring-segment-routing-use-cases]. The Adj-SID Sub-TLV 1167 has the following format: 1169 0 1 2 3 1170 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 1171 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1172 | Type | Length | 1173 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1174 | Flags | Weight | Reserved | 1175 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1176 | SID/Label/Index (variable) | 1177 +---------------------------------------------------------------+ 1179 where: 1181 Type: TBD, suggested value 5. 1183 Length: variable. 1185 Flags. 1 octet field of following flags: 1187 0 1 2 3 4 5 6 7 1188 +-+-+-+-+-+-+-+-+ 1189 |B|V|L|G|P| | 1190 +-+-+-+-+-+-+-+-+ 1192 where: 1194 B-Flag: Backup-flag. If set, the Adj-SID refers to an 1195 adjacency that is eligible for protection (e.g.: using IPFRR or 1196 MPLS-FRR) as described in section 3.5 of 1197 [I-D.ietf-spring-segment-routing]. 1199 The V-Flag: Value/Index Flag. If set, then the Adj-SID carries 1200 an absolute value. If not set, then the Adj-SID carries an 1201 index. 1203 The L-Flag: Local/Global Flag. If set, then the value/index 1204 carried by the Adj-SID has local significance. If not set, 1205 then the value/index carried by this Sub-TLV has global 1206 significance. 1208 The G-Flag. Group Flag. When set, the G-Flag indicates that 1209 the Adj-SID refers to a set of adjacencies (and therefore MAY 1210 be assigned to other adjacencies as well). 1212 P-Flag. Persistent flag. When set, the P-Flag indicates that 1213 the Adj-SID is persistently allocated, i.e., the Adj-SID value 1214 remains consistent across router restart and/or interface flap. 1216 Other bits: Reserved. These MUST be zero when sent and are 1217 ignored when received. 1219 Weight: weight used for load-balancing purposes. The use of the 1220 weight is defined in section 3.5.1 of 1221 [I-D.ietf-spring-segment-routing]. 1223 SID/Index/Label: label or index value depending on the V-bit 1224 setting. 1226 Examples: 1228 A 32 bit global index defining the offset in the SID/Label 1229 space advertised by this router - in this case the V and L 1230 flags MUST NOT be set. 1232 A 24 bit local label where the 20 rightmost bits are used 1233 for encoding the label value - in this case the V and L 1234 flags MUST be set. 1236 16 octet IPv6 address - in this case the V-flag MUST be set. 1237 The L-flag MUST NOT be set if the IPv6 address is globally 1238 unique. 1240 An SR capable router MAY allocate an Adj-SID for each of its 1241 adjacencies and set the B-Flag when the adjacency is eligible for 1242 protection by an FRR mechanism (IP or MPLS) as described in section 1243 3.5 of [I-D.ietf-spring-segment-routing]. 1245 An SR capable router MAY allocate more than one Adj-SID to an 1246 adjacency 1248 An SR capable router MAY allocate the same Adj-SID to different 1249 adjacencies 1251 When the P-flag is not set, the Adj-SID MAY be persistent. When the 1252 P-flag is set, the Adj-SID MUST be persistent. 1254 7.2. LAN Adj-SID Sub-TLV 1256 The LAN Adj-SID is an optional Sub-TLV of the Router-Link TLV. It 1257 MAY appear multiple times in the Router-Link TLV. It is used to 1258 advertise a SID/Label for an adjacency to a non-DR neighbor on a 1259 broadcast or NBMA network. 1261 0 1 2 3 1262 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 1263 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1264 | Type | Length | 1265 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1266 | Flags | Weight | Reserved | 1267 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1268 | Neighbor ID | 1269 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1270 | SID/Label/Index (variable) | 1271 +---------------------------------------------------------------+ 1273 where: 1275 Type: TBD, suggested value 6. 1277 Length: variable. 1279 Flags. 1 octet field of following flags: 1281 0 1 2 3 4 5 6 7 1282 +-+-+-+-+-+-+-+-+ 1283 |B|V|L|G|P| | 1284 +-+-+-+-+-+-+-+-+ 1286 where: 1288 B-Flag: Backup-flag: set if the LAN-Adj-SID refer to an 1289 adjacency that is eligible for protection (e.g.: using IPFRR or 1290 MPLS-FRR) as described in section 3.1 of 1291 [I-D.filsfils-spring-segment-routing-use-cases]. 1293 The V-Flag: Value/Index Flag. If set, then the LAN Adj-SID 1294 carries an absolute value. If not set, then the LAN Adj-SID 1295 carries an index. 1297 The L-Flag: Local/Global Flag. If set, then the value/index 1298 carried by the LAN Adj-SID has local significance. If not set, 1299 then the value/index carried by this subTLV has global 1300 significance. 1302 The G-Flag. Group Flag. When set, the G-Flag indicates that 1303 the LAN Adj-SID refers to a set of adjacencies (and therefore 1304 MAY be assigned to other adjacencies as well). 1306 P-Flag. Persistent flag. When set, the P-Flag indicates that 1307 the Adj-SID is persistently allocated, i.e., the Adj-SID value 1308 remains consistent across router restart and/or interface flap. 1310 Other bits: Reserved. These MUST be zero when sent and are 1311 ignored when received. 1313 Weight: weight used for load-balancing purposes. The use of the 1314 weight is defined in section 3.5.1 of 1315 [I-D.ietf-spring-segment-routing]. 1317 Neighbor ID: The Router ID of the neighbor for which the Adj-SID 1318 is advertised. 1320 SID/Index/Label: label or index value depending on the V-bit 1321 setting. 1323 Examples: 1325 A 32 bit global index defining the offset in the SID/Label 1326 space advertised by this router - in this case the V and L 1327 flags MUST NOT be set. 1329 A 24 bit local label where the 20 rightmost bits are used 1330 for encoding the label value - in this case the V and L 1331 flags MUST be set. 1333 16 octet IPv6 address - in this case the V-flag MUST be set. 1334 The L-flag MUST NOT be set if the IPv6 address is globally 1335 unique. 1337 When the P-flag is not set, the Adj-SID MAY be persistent. When 1338 the P-flag is set, the Adj-SID MUST be persistent. 1340 8. Elements of Procedure 1342 8.1. Intra-area Segment routing in OSPFv3 1344 An OSPFv3 router that supports segment routing MAY advertise Prefix- 1345 SIDs for any prefix that it is advertising reachability for (e.g., 1346 loopback IP address) as described in Section 5. 1348 If multiple routers advertise a Prefix-SID for the same prefix, then 1349 the Prefix-SID MUST be the same. This is required in order to allow 1350 traffic load-balancing when multiple equal cost paths to the 1351 destination exist in the network. 1353 The Prefix-SID can also be advertised by the SR Mapping Servers (as 1354 described in [I-D.filsfils-spring-segment-routing-ldp-interop]). The 1355 Mapping Server advertises Prefix-SID for remote prefixes that exist 1356 in the network. Multiple Mapping Servers can advertise Prefix-SID 1357 for the same prefix, in which case the same Prefix-SID MUST be 1358 advertised by all of them. The SR Mapping Server could use either 1359 area scope or autonomous system flooding scope when advertising 1360 Prefix SID for prefixes, based on the configuration of the SR Mapping 1361 Server. Depending on the flooding scope used, the SR Mapping Server 1362 chooses the LSA that will be used. If the area flooding scope is 1363 needed, E-Intra-Area-Prefix-LSA ([I-D.ietf-ospf-ospfv3-lsa-extend]) 1364 is used. If autonomous system flooding scope is needed, E-AS- 1365 External-LSA ([I-D.ietf-ospf-ospfv3-lsa-extend]) is used. 1367 When a Prefix-SID is advertised by the Mapping Server, which is 1368 indicated by the M-flag in the Prefix-SID Sub-TLV (Section 5), the 1369 route type as implied by the LSA type is ignored and the Prefix-SID 1370 is bound to the corresponding prefix independent of the route type. 1372 Advertisement of the Prefix-SID by the Mapping Server using Inter- 1373 Area Prefix TLV, External-Prefix TLV or Intra-Area-Prefix TLV 1374 ([I-D.ietf-ospf-ospfv3-lsa-extend]) does not itself contribute to the 1375 prefix reachability. The NU-bit MUST be set in the PrefixOptions 1376 field of the LSA which is used by the Mapping Server to advertise SID 1377 or SID range, which prevents the advertisement to contribute to 1378 prefix reachability. 1380 SR Mapping Server MUST use OSPF Extended Prefix Range TLV when 1381 advertising SIDs for prefixes. Prefixes of different route-types can 1382 be combined in a single OSPF Extended Prefix Range TLV advertised by 1383 the SR Mapping Server. 1385 Area scoped OSPF Extended Prefix Range TLV are propagated between 1386 areas. Similar to propagation of prefixes between areas, ABR only 1387 propagates the OSPF Extended Prefix Range TLV that it considers to be 1388 the best from the set it received. The rules used to pick the best 1389 OSPF Extended Prefix Range TLV is described in Section 4. 1391 When propagating OSPF Extended Prefix Range TLV between areas, ABR 1392 MUST set the IA-Flag, that is used to prevent redundant flooding of 1393 the OSPF Extended Prefix Range TLV between areas as described in 1394 Section 4. 1396 8.2. Inter-area Segment routing in OSPFv3 1398 In order to support SR in a multi-area environment, OSPFv3 must 1399 propagate Prefix-SID information between areas. The following 1400 procedure is used in order to propagate Prefix SIDs between areas. 1402 When an OSPFv3 ABR advertises a Inter-Area-Prefix-LSA from an intra- 1403 area prefix to all its connected areas, it will also include Prefix- 1404 SID Sub-TLV, as described in Section 5. The Prefix-SID value will be 1405 set as follows: 1407 The ABR will look at its best path to the prefix in the source 1408 area and find out the advertising router associated with the best 1409 path to that prefix. 1411 The ABR will then determine if such router advertised a Prefix-SID 1412 for the prefix and use it when advertising the Prefix-SID to other 1413 connected areas. 1415 If no Prefix-SID was advertised for the prefix in the source area 1416 by the router that contributes to the best path to the prefix, the 1417 originating ABR will use the Prefix-SID advertised by any other 1418 router when propagating Prefix-SID for the prefix to other areas. 1420 When an OSPFv3 ABR advertises Inter-Area-Prefix-LSA LSAs from an 1421 inter-area route to all its connected areas it will also include 1422 Prefix-SID Sub-TLV, as described in Section 5. The Prefix-SID value 1423 will be set as follows: 1425 The ABR will look at its best path to the prefix in the source 1426 area and find out the advertising router associated with the best 1427 path to that prefix. 1429 The ABR will then look if such router advertised a Prefix-SID for 1430 the prefix and use it when advertising the Prefix-SID to other 1431 connected areas. 1433 If no Prefix-SID was advertised for the prefix in the source area 1434 by the ABR that contributes to the best path to the prefix, the 1435 originating ABR will use the Prefix-SID advertised by any other 1436 router when propagating Prefix-SID for the prefix to other areas. 1438 8.3. SID for External Prefixes 1440 AS-External-LSAs are flooded domain wide. When an ASBR, which 1441 supports SR, generates E-AS-External-LSA, it should also include 1442 Prefix-SID Sub-TLV, as described in Section 5. The Prefix-SID value 1443 will be set to the SID that has been reserved for that prefix. 1445 When an NSSA ASBR translates an E-NSSA-LSA into an E-AS-External-LSA, 1446 it should also advertise the Prefix-SID for the prefix. The NSSA ABR 1447 determines its best path to the prefix advertised in the translated 1448 E-NSSA-LSA and finds the advertising router associated with that 1449 path. If the advertising router has advertised a Prefix-SID for the 1450 prefix, then the NSSA ABR uses it when advertising the Prefix-SID in 1451 the E-AS-External-LSA. Otherwise the Prefix-SID advertised by any 1452 other router will be used. 1454 8.4. Advertisement of Adj-SID 1456 The Adjacency Segment Routing Identifier (Adj-SID) is advertised 1457 using the Adj-SID Sub-TLV as described in Section 7. 1459 8.4.1. Advertisement of Adj-SID on Point-to-Point Links 1461 An Adj-SID MAY be advertised for any adjacency on p2p link that is in 1462 a state 2-Way or higher. If the adjacency on a p2p link transitions 1463 from the FULL state, then the Adj-SID for that adjacency MAY be 1464 removed from the area. If the adjacency transitions to a state lower 1465 then 2-Way, then the Adj-SID advertisement MUST be removed from the 1466 area. 1468 8.4.2. Adjacency SID on Broadcast or NBMA Interfaces 1470 Broadcast or NBMA networks in OSPFv3 are represented by a star 1471 topology where the Designated Router (DR) is the central point to 1472 which all other routers on the broadcast or NBMA network connect. As 1473 a result, routers on the broadcast or NBMA network advertise only 1474 their adjacency to the DR. Routers that do not act as DR do not form 1475 or advertise adjacencies with each other. They do, however, maintain 1476 a 2-Way adjacency state with each other and are directly reachable. 1478 When Segment Routing is used, each router on the broadcast or NBMA 1479 network MAY advertise the Adj-SID for its adjacency to the DR using 1480 Adj-SID Sub-TLV as described in Section 7.1. 1482 SR capable routers MAY also advertise an Adj-SID for other neighbors 1483 (e.g. BDR, DR-OTHER) on the broadcast or NBMA network using the LAN 1484 ADJ-SID Sub-TLV as described in Section 7.2. 1486 9. IANA Considerations 1488 This specification updates several existing OSPF registries. 1490 9.1. OSPF Router Information (RI) TLVs Registry 1492 o 8 (IANA Preallocated) - SR-Algorithm TLV 1494 o 9 (IANA Preallocated) - SID/Label Range TLV 1496 o 12 - SR Local Block Sub-TLV 1498 o 13 - SRMS Preference Sub-TLV 1500 9.2. OSPFv3 Extend-LSA TLV Registry 1502 Following values are allocated: 1504 o suggested value 9 - OSPF Extended Prefix Range TLV 1506 9.3. OSPFv3 Extend-LSA Sub-TLV registry 1508 o suggested value 3 - SID/Label Sub-TLV 1510 o suggested value 4 - Prefix SID Sub-TLV 1512 o suggested value 5 - Adj-SID Sub-TLV 1514 o suggested value 6 - LAN Adj-SID Sub-TLV 1516 o suggested value 7 - SID/Label Binding Sub-TLV 1518 o suggested value 8 - ERO Metric Sub-TLV 1520 o suggested value 9 - IPv4 ERO Sub-TLV 1522 o suggested value 10 - IPv6 ERO Sub-TLV 1524 o suggested value 11 - Unnumbered Interface ID ERO Sub-TLV 1526 o suggested value 12 - IPv4 Backup ERO Sub-TLV 1528 o suggested value 13 - IPv6 Backup ERO Sub-TLV 1530 o suggested value 14 - Unnumbered Interface ID Backup ERO Sub-TLV 1532 10. Security Considerations 1534 Implementations must assure that malformed permutations of the newly 1535 defined sub-TLvs do not result in errors which cause hard OSPFv3 1536 failures. 1538 11. Acknowledgements 1540 Thanks to Acee Lindem for the detail review of the draft, 1541 corrections, as well as discussion about details of the encoding. 1543 We would like to thank Anton Smirnov for his contribution. 1545 Many thanks to Yakov Rekhter, John Drake and Shraddha Hedge for their 1546 contribution on earlier definition of the "Binding / MPLS Label TLV". 1548 12. References 1550 12.1. Normative References 1552 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1553 Requirement Levels", BCP 14, RFC 2119, 1554 DOI 10.17487/RFC2119, March 1997, 1555 . 1557 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 1558 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 1559 Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, 1560 . 1562 [RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links 1563 in Resource ReSerVation Protocol - Traffic Engineering 1564 (RSVP-TE)", RFC 3477, DOI 10.17487/RFC3477, January 2003, 1565 . 1567 [RFC4970] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and 1568 S. Shaffer, "Extensions to OSPF for Advertising Optional 1569 Router Capabilities", RFC 4970, DOI 10.17487/RFC4970, July 1570 2007, . 1572 [RFC7770] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and 1573 S. Shaffer, "Extensions to OSPF for Advertising Optional 1574 Router Capabilities", RFC 7770, DOI 10.17487/RFC7770, 1575 February 2016, . 1577 12.2. Informative References 1579 [I-D.filsfils-spring-segment-routing-ldp-interop] 1580 Filsfils, C., Previdi, S., Bashandy, A., Decraene, B., 1581 Litkowski, S., Horneffer, M., Milojevic, I., Shakir, R., 1582 Ytti, S., Henderickx, W., Tantsura, J., and E. Crabbe, 1583 "Segment Routing interoperability with LDP", draft- 1584 filsfils-spring-segment-routing-ldp-interop-02 (work in 1585 progress), September 2014. 1587 [I-D.filsfils-spring-segment-routing-use-cases] 1588 Filsfils, C., Francois, P., Previdi, S., Decraene, B., 1589 Litkowski, S., Horneffer, M., Milojevic, I., Shakir, R., 1590 Ytti, S., Henderickx, W., Tantsura, J., Kini, S., and E. 1591 Crabbe, "Segment Routing Use Cases", draft-filsfils- 1592 spring-segment-routing-use-cases-01 (work in progress), 1593 October 2014. 1595 [I-D.ietf-ospf-ospfv3-lsa-extend] 1596 Lindem, A., Mirtorabi, S., Roy, A., and F. Baker, "OSPFv3 1597 LSA Extendibility", draft-ietf-ospf-ospfv3-lsa-extend-13 1598 (work in progress), October 2016. 1600 [I-D.ietf-spring-conflict-resolution] 1601 Ginsberg, L., Psenak, P., Previdi, S., and M. Pilka, 1602 "Segment Routing Conflict Resolution", draft-ietf-spring- 1603 conflict-resolution-01 (work in progress), June 2016. 1605 [I-D.ietf-spring-segment-routing] 1606 Filsfils, C., Previdi, S., Bashandy, A., Decraene, B., 1607 Litkowski, S., Horneffer, M., Shakir, R., Tantsura, J., 1608 and E. Crabbe, "Segment Routing Architecture", draft-ietf- 1609 spring-segment-routing-01 (work in progress), February 1610 2015. 1612 [I-D.minto-rsvp-lsp-egress-fast-protection] 1613 Jeganathan, J., Gredler, H., and Y. Shen, "RSVP-TE LSP 1614 egress fast-protection", draft-minto-rsvp-lsp-egress-fast- 1615 protection-03 (work in progress), November 2013. 1617 [I-D.previdi-6man-segment-routing-header] 1618 Previdi, S., Filsfils, C., Field, B., Leung, I., Linkova, 1619 J., Kosugi, T., Vyncke, E., and D. Lebrun, "IPv6 Segment 1620 Routing Header (SRH)", draft-previdi-6man-segment-routing- 1621 header-08 (work in progress), October 2015. 1623 Authors' Addresses 1625 Peter Psenak (editor) 1626 Cisco Systems, Inc. 1627 Apollo Business Center 1628 Mlynske nivy 43 1629 Bratislava 821 09 1630 Slovakia 1632 Email: ppsenak@cisco.com 1634 Stefano Previdi (editor) 1635 Cisco Systems, Inc. 1636 Via Del Serafico, 200 1637 Rome 00142 1638 Italy 1640 Email: sprevidi@cisco.com 1641 Clarence Filsfils 1642 Cisco Systems, Inc. 1643 Brussels 1644 Belgium 1646 Email: cfilsfil@cisco.com 1648 Hannes Gredler 1649 RtBrick Inc. 1650 Austria 1652 Email: hannes@rtbrick.com 1654 Rob Shakir 1655 Google, Inc. 1656 1600 Amphitheatre Parkway 1657 Mountain View, CA 94043 1658 US 1660 Email: robjs@google.com 1662 Wim Henderickx 1663 Nokia 1664 Copernicuslaan 50 1665 Antwerp 2018 1666 BE 1668 Email: wim.henderickx@nokia.com 1670 Jeff Tantsura 1671 Individual 1672 US 1674 Email: jefftant.ietf@gmail.com