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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Inter-Domain Routing S. Previdi, Ed. 3 Internet-Draft 4 Intended status: Standards Track K. Talaulikar 5 Expires: November 16, 2018 C. Filsfils 6 Cisco Systems, Inc. 7 H. Gredler 8 RtBrick Inc. 9 M. Chen 10 Huawei Technologies 11 May 15, 2018 13 BGP Link-State extensions for Segment Routing 14 draft-ietf-idr-bgp-ls-segment-routing-ext-07 16 Abstract 18 Segment Routing (SR) allows for a flexible definition of end-to-end 19 paths by encoding paths as sequences of topological sub-paths, called 20 "segments". These segments are advertised by routing protocols e.g. 21 by the link state routing protocols (IS-IS, OSPFv2 and OSPFv3) within 22 IGP topologies. 24 This draft defines extensions to the BGP Link-state address-family in 25 order to carry segment routing information via BGP. 27 Requirements Language 29 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 30 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 31 document are to be interpreted as described in RFC 2119 [RFC2119]. 33 Status of This Memo 35 This Internet-Draft is submitted in full conformance with the 36 provisions of BCP 78 and BCP 79. 38 Internet-Drafts are working documents of the Internet Engineering 39 Task Force (IETF). Note that other groups may also distribute 40 working documents as Internet-Drafts. The list of current Internet- 41 Drafts is at https://datatracker.ietf.org/drafts/current/. 43 Internet-Drafts are draft documents valid for a maximum of six months 44 and may be updated, replaced, or obsoleted by other documents at any 45 time. It is inappropriate to use Internet-Drafts as reference 46 material or to cite them other than as "work in progress." 48 This Internet-Draft will expire on November 16, 2018. 50 Copyright Notice 52 Copyright (c) 2018 IETF Trust and the persons identified as the 53 document authors. All rights reserved. 55 This document is subject to BCP 78 and the IETF Trust's Legal 56 Provisions Relating to IETF Documents 57 (https://trustee.ietf.org/license-info) in effect on the date of 58 publication of this document. Please review these documents 59 carefully, as they describe your rights and restrictions with respect 60 to this document. Code Components extracted from this document must 61 include Simplified BSD License text as described in Section 4.e of 62 the Trust Legal Provisions and are provided without warranty as 63 described in the Simplified BSD License. 65 Table of Contents 67 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 68 2. BGP-LS Extensions for Segment Routing . . . . . . . . . . . . 5 69 2.1. Node Attributes TLVs . . . . . . . . . . . . . . . . . . 5 70 2.1.1. SID/Label Sub-TLV . . . . . . . . . . . . . . . . . . 6 71 2.1.2. SR-Capabilities TLV . . . . . . . . . . . . . . . . . 6 72 2.1.3. SR-Algorithm TLV . . . . . . . . . . . . . . . . . . 7 73 2.1.4. SR Local Block TLV . . . . . . . . . . . . . . . . . 8 74 2.1.5. SRMS Preference TLV . . . . . . . . . . . . . . . . . 9 75 2.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 9 76 2.2.1. Adjacency SID TLV . . . . . . . . . . . . . . . . . . 10 77 2.2.2. LAN Adjacency SID TLV . . . . . . . . . . . . . . . . 11 78 2.2.3. L2 Bundle Member . . . . . . . . . . . . . . . . . . 12 79 2.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 13 80 2.3.1. Prefix-SID TLV . . . . . . . . . . . . . . . . . . . 14 81 2.3.2. Prefix Attribute Flags TLV . . . . . . . . . . . . . 15 82 2.3.3. Source Router Identifier (Source Router-ID) TLV . . . 16 83 2.3.4. Range TLV . . . . . . . . . . . . . . . . . . . . . . 16 84 2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs . . . . . 18 85 2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs . 18 86 3. Implementation Status . . . . . . . . . . . . . . . . . . . . 19 87 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 88 4.1. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . 20 89 5. Manageability Considerations . . . . . . . . . . . . . . . . 21 90 5.1. Operational Considerations . . . . . . . . . . . . . . . 21 91 5.2. Management Considerations . . . . . . . . . . . . . . . . 21 92 6. Security Considerations . . . . . . . . . . . . . . . . . . . 21 93 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22 94 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22 95 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 96 9.1. Normative References . . . . . . . . . . . . . . . . . . 22 97 9.2. Informative References . . . . . . . . . . . . . . . . . 23 98 9.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 24 99 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 101 1. Introduction 103 Segment Routing (SR) allows for a flexible definition of end-to-end 104 paths by combining sub-paths called "segments". A segment can 105 represent any instruction, topological or service-based. A segment 106 can have a local semantic to an SR node or global within a domain. 107 Within IGP topologies an SR path is encoded as a sequence of 108 topological sub-paths, called "IGP segments". These segments are 109 advertised by the link-state routing protocols (IS-IS, OSPFv2 and 110 OSPFv3). 112 Two types of IGP segments are defined, Prefix segments and Adjacency 113 segments. Prefix segments, by default, represent an ECMP-aware 114 shortest-path to a prefix, as per the state of the IGP topology. 115 Adjacency segments represent a hop over a specific adjacency between 116 two nodes in the IGP. A prefix segment is typically a multi-hop path 117 while an adjacency segment, in most of the cases, is a one-hop path. 118 [I-D.ietf-spring-segment-routing]. 120 When Segment Routing is enabled in a IGP domain, segments are 121 advertised in the form of Segment Identifiers (SIDs). The IGP link- 122 state routing protocols have been extended to advertise SIDs and 123 other SR-related information. IGP extensions are described in: IS-IS 124 [I-D.ietf-isis-segment-routing-extensions], OSPFv2 125 [I-D.ietf-ospf-segment-routing-extensions] and OSPFv3 126 [I-D.ietf-ospf-ospfv3-segment-routing-extensions]. Using these 127 extensions, Segment Routing can be enabled within an IGP domain. 129 +------------+ 130 | Consumer | 131 +------------+ 132 ^ 133 | 134 v 135 +-------------------+ 136 | BGP Speaker | +-----------+ 137 | (Route-Reflector) | | Consumer | 138 +-------------------+ +-----------+ 139 ^ ^ ^ ^ 140 | | | | 141 +---------------+ | +-------------------+ | 142 | | | | 143 v v v v 144 +-----------+ +-----------+ +-----------+ 145 | BGP | | BGP | | BGP | 146 | Speaker | | Speaker | . . . | Speaker | 147 +-----------+ +-----------+ +-----------+ 148 ^ ^ ^ 149 | | | 150 IGP IGP IGP 152 Figure 1: Link State info collection 154 Segment Routing (SR) allows advertisement of single or multi-hop 155 paths. The flooding scope for the IGP extensions for Segment routing 156 is IGP area-wide. Consequently, the contents of a Link State 157 Database (LSDB) or a Traffic Engineering Database (TED) has the scope 158 of an IGP area and therefore, by using the IGP alone it is not enough 159 to construct segments across multiple IGP Area or AS boundaries. 161 In order to address the need for applications that require 162 topological visibility across IGP areas, or even across Autonomous 163 Systems (AS), the BGP-LS address-family/sub-address-family have been 164 defined to allow BGP to carry Link-State information. The BGP 165 Network Layer Reachability Information (NLRI) encoding format for 166 BGP-LS and a new BGP Path Attribute called the BGP-LS attribute are 167 defined in [RFC7752]. The identifying key of each Link-State object, 168 namely a node, link, or prefix, is encoded in the NLRI and the 169 properties of the object are encoded in the BGP-LS attribute. 170 Figure 1 describes a typical deployment scenario. In each IGP area, 171 one or more nodes are configured with BGP-LS. These BGP speakers 172 form an IBGP mesh by connecting to one or more route-reflectors. 173 This way, all BGP speakers (specifically the route-reflectors) obtain 174 Link-State information from all IGP areas (and from other ASes from 175 EBGP peers). An external component connects to the route-reflector 176 to obtain this information (perhaps moderated by a policy regarding 177 what information is or isn't advertised to the external component). 179 This document describes extensions to BGP-LS to advertise the SR 180 information. An external component (e.g., a controller) then can 181 collect SR information from across an SR domain and construct the 182 end-to-end path (with its associated SIDs) that need to be applied to 183 an incoming packet to achieve the desired end-to-end forwarding. 184 Here the SR domain is defined as a single administrative domain that 185 may be comprised of a single AS or multiple ASes under consolidated 186 global SID administration. 188 2. BGP-LS Extensions for Segment Routing 190 This document defines SR extensions to BGP-LS and specifies the TLVs 191 and sub-TLVs for advertising SR information. Section 2.4 and 192 Section 2.5 illustrates the equivalent TLVs and sub-TLVs in IS-IS, 193 OSPFv2 and OSPFv3 protocols. 195 BGP-LS [RFC7752] defines the BGP-LS NLRI that can be a Node NLRI, a 196 Link NLRI or a Prefix NLRI. The corresponding BGP-LS attribute is a 197 Node Attribute, a Link Attribute or a Prefix Attribute. BGP-LS 198 [RFC7752] defines the TLVs that map link-state information to BGP-LS 199 NLRI and the BGP-LS attribute. This document adds additional BGP-LS 200 attribute TLVs in order to encode SR information. 202 2.1. Node Attributes TLVs 204 The following Node Attribute TLVs are defined: 206 +-----------------+----------+---------------+ 207 | Description | Length | Section | 208 +-----------------+----------+---------------+ 209 | SID/Label | variable | Section 2.1.1 | 210 | SR Capabilities | variable | Section 2.1.2 | 211 | SR Algorithm | variable | Section 2.1.3 | 212 | SR Local Block | variable | Section 2.1.4 | 213 | SRMS Preference | variable | Section 2.1.5 | 214 +-----------------+----------+---------------+ 216 Table 1: Node Attribute TLVs 218 These TLVs can ONLY be added to the Node Attribute associated with 219 the Node NLRI that originates the corresponding SR TLV. 221 2.1.1. SID/Label Sub-TLV 223 The SID/Label TLV is used as sub-TLV by the SR-Capabilities 224 (Section 2.1.2) and SRLB (Section 2.1.4) TLVs and has the following 225 format: 227 0 1 2 3 228 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 1 229 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 230 | Type | Length | 231 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 232 | SID/Label (variable) | 233 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 235 where: 237 Type: TBD, see Section 4. 239 Length: Variable, 3 or 4. 241 SID/Label: If length is set to 3, then the 20 rightmost bits 242 represent a label. If length is set to 4, then the value 243 represents a 32 bit SID. 245 The receiving router MUST ignore the SID/Label sub-TLV if the 246 length is other then 3 or 4. 248 2.1.2. SR-Capabilities TLV 250 The SR-Capabilities TLV is used in order to advertise the node's SR 251 Capabilities and its Segment Routing Global Base (SRGB) range(s). 252 This information is derived from the protocol specific 253 advertisements. 255 o IS-IS, as defined by the SR-Capabilities TLV in 256 [I-D.ietf-isis-segment-routing-extensions]. 258 o OSPFv2/OSPFv3, as defined by the SID/Label Range TLV in 259 [I-D.ietf-ospf-segment-routing-extensions] and 260 [I-D.ietf-ospf-ospfv3-segment-routing-extensions]. 262 The SR Capabilities TLV has following format: 264 0 1 2 3 265 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 1 266 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 267 | Type | Length | 268 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 269 | Flags | Reserved | 270 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 272 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 273 | Range Size | 274 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 275 // SID/Label sub-TLV (variable) // 276 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 278 Type: TBD, see Section 4. 280 Length: Variable. 282 Flags: 1 octet of flags as defined in 283 [I-D.ietf-isis-segment-routing-extensions]. 285 Reserved: 1 octet that SHOULD be set to 0 and MUST be ignored on 286 receipt. 288 One or more entries, each of which have the following format: 290 Range Size: 3 octet value indicating the number of labels in 291 the range. 293 SID/Label sub-TLV (as defined in Section 2.1.1) which encodes 294 the first label in the range. 296 2.1.3. SR-Algorithm TLV 298 The SR-Algorithm TLV has the following format: 300 0 1 2 3 301 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 1 302 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 303 | Type | Length | 304 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 305 | Algorithm 1 | Algorithm... | Algorithm N | | 306 +- -+ 307 | | 308 + + 310 where: 312 Type: TBD, see Section 4. 314 Length: Variable. 316 Algorithm: 1 octet identifying the algorithm. 318 2.1.4. SR Local Block TLV 320 The SR Local Block (SRLB) TLV contains the range(s) of labels the 321 node has reserved for local SIDs. Local SIDs are used, e.g., in IGP 322 (IS-IS, OSPF) for Adjacency-SIDs, and may also be allocated by 323 components other than IGP protocols. As an example, an application 324 or a controller may instruct a node to allocate a specific local SID. 325 Therefore, in order for such applications or controllers to know the 326 range of local SIDs available, it is required that the node 327 advertises its SRLB. 329 The SRLB TLV has the following format: 331 0 1 2 3 332 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 1 333 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 334 | Type | Length | 335 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 336 | Flags | Reserved | 337 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 339 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 340 | Range Size | 341 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 342 // SID/Label sub-TLV (variable) // 343 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 345 Type: TBD, see Section 4. 347 Length: Variable. 349 Flags: 1 octet of flags. None are defined at this stage. 351 Reserved: 1 octet that SHOULD be set to 0 and MUST be ignored on 352 receipt. 354 One or more entries, each of which have the following format: 356 Range Size: 3 octet value indicating the number of labels in 357 the range. 359 SID/Label sub-TLV (as defined in Section 2.1.1) which encodes 360 the first label in the range. 362 2.1.5. SRMS Preference TLV 364 The Segment Routing Mapping Server (SRMS) Preference TLV is used in 365 order to associate a preference with SRMS advertisements from a 366 particular source. 368 The SRMS Preference TLV has following format: 370 0 1 2 3 371 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 1 372 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 373 | Type | Length | 374 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 375 | Preference | 376 +-+-+-+-+-+-+-+-+ 378 Type: TBD, see Section 4. 380 Length: 1. 382 Preference: 1 octet. Unsigned 8 bit SRMS preference. 384 The use of the SRMS Preference TLV is defined in 385 [I-D.ietf-isis-segment-routing-extensions], 386 [I-D.ietf-ospf-segment-routing-extensions] and 387 [I-D.ietf-ospf-ospfv3-segment-routing-extensions]. 389 2.2. Link Attribute TLVs 391 The following Link Attribute TLVs are are defined: 393 +----------------------------------------+----------+---------------+ 394 | Description | Length | Section | 395 +----------------------------------------+----------+---------------+ 396 | Adjacency Segment Identifier (Adj-SID) | variable | Section 2.2.1 | 397 | TLV | | | 398 | LAN Adjacency Segment Identifier (Adj- | variable | Section 2.2.2 | 399 | SID) TLV | | | 400 | L2 Bundle Member TLV | variable | Section 2.2.3 | 401 +----------------------------------------+----------+---------------+ 403 Table 2: Link Attribute TLVs 405 These TLVs can ONLY be added to the Link Attribute associated with 406 the link whose local node originates the corresponding TLV. 408 For a LAN, normally a node only announces its adjacency to the IS-IS 409 pseudo-node (or the equivalent OSPF Designated and Backup Designated 410 Routers)[I-D.ietf-isis-segment-routing-extensions]. The LAN 411 Adjecency Segment TLV allows a node to announce adjacencies to all 412 other nodes attached to the LAN in a single instance of the BGP-LS 413 Link NLRI. Without this TLV, the corresponding BGP-LS link NLRI 414 would need to be originated for each additional adjacency in order to 415 advertise the SR TLVs for these neighbor adjacencies. 417 2.2.1. Adjacency SID TLV 419 The Adjacency SID (Adj-SID) TLV has the following format: 421 0 1 2 3 422 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 1 423 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 424 | Type | Length | 425 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 426 | Flags | Weight | Reserved | 427 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 428 | SID/Label/Index (variable) | 429 +---------------------------------------------------------------+ 431 where: 433 Type: TBD, see Section 4. 435 Length: Variable, 7 or 8 depending on Label or Index encoding of 436 the SID 438 Flags. 1 octet field of following flags as defined in 439 [I-D.ietf-isis-segment-routing-extensions], 440 [I-D.ietf-ospf-segment-routing-extensions] and 441 [I-D.ietf-ospf-ospfv3-segment-routing-extensions]. 443 Weight: Weight used for load-balancing purposes. 445 Reserved: 2 octets that SHOULD be set to 0 and MUST be ignored on 446 receipt. 448 SID/Index/Label: Label or index value depending on the flags 449 setting as defined in [I-D.ietf-isis-segment-routing-extensions], 450 [I-D.ietf-ospf-segment-routing-extensions] and 451 [I-D.ietf-ospf-ospfv3-segment-routing-extensions]. 453 2.2.2. LAN Adjacency SID TLV 455 The LAN Adjacency SID (LAN-Adj-SID-SID) TLV has the following format: 457 0 1 2 3 458 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 1 459 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 460 | Type | Length | 461 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 462 | Flags | Weight | Reserved | 463 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 465 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 466 | OSPF Neighbor ID / IS-IS System-ID | 467 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 468 | | 469 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 471 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 472 | SID/Label/Index (variable) | 473 +---------------------------------------------------------------+ 475 where: 477 Type: TBD, see Section 4. 479 Length: Variable. For ISIS it would be 13 or 14 depending on 480 Label or Index encoding of the SID. For OSPF it would be 11 or 12 481 depending on Label or Index encoding of the SID. 483 Flags. 1 octet field of following flags as defined in 484 [I-D.ietf-isis-segment-routing-extensions], 485 [I-D.ietf-ospf-segment-routing-extensions] and 486 [I-D.ietf-ospf-ospfv3-segment-routing-extensions]. 488 Weight: Weight used for load-balancing purposes. 490 Reserved: 2 octets that SHOULD be set to 0 and MUST be ignored on 491 receipt. 493 SID/Index/Label: Label or index value depending on the flags 494 setting as defined in [I-D.ietf-isis-segment-routing-extensions], 495 [I-D.ietf-ospf-segment-routing-extensions] and 496 [I-D.ietf-ospf-ospfv3-segment-routing-extensions]. 498 2.2.3. L2 Bundle Member 500 The L2 Bundle Member Attribute TLV identifies an L2 Bundle Member 501 link which in turn is associated with a parent L3 link. The L3 link 502 is described by the Link NLRI defined in [RFC7752] and the L2 Bundle 503 Member Attribute TLV is associated with the Link NLRI. The TLV MAY 504 include sub-TLVs which describe attributes associated with the bundle 505 member. The identified bundle member represents a unidirectional 506 path from the originating router to the neighbor specified in the 507 parent L3 Link. Multiple L2 Bundle Member Attribute TLVs MAY be 508 associated with a Link NLRI. 510 The L2 Bundle Member Attribute TLV has the following format: 512 0 1 2 3 513 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 1 514 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 515 | Type | Length | 516 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 518 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 519 | L2 Bundle Member Descriptor | 520 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 521 // Link attribute sub-TLVs(variable) // 522 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 524 where: 526 Type: TBD, see Section 4. 528 Length: Variable. 530 L2 Bundle Member Descriptor: A Link Local Identifier as defined in 531 [RFC4202]. 533 Link attributes for L2 Bundle Member Links are advertised as sub-TLVs 534 of the L2Bundle Member Attribute TLV. The sub-TLVs are identical to 535 existing BGP-LS TLVs as identified in the table below. 537 +-----------+----------------------------+--------------------------+ 538 | TLV Code | Description | Reference Document | 539 | Point | | | 540 +-----------+----------------------------+--------------------------+ 541 | 1088 | Administrative group | [RFC7752] | 542 | | (color) | | 543 | 1089 | Maximum link bandwidth | [RFC7752] | 544 | 1090 | Max. reservable link | [RFC7752] | 545 | | bandwidth | | 546 | 1091 | Unreserved bandwidth | [RFC7752] | 547 | 1092 | TE default metric | [RFC7752] | 548 | 1093 | Link protection type | [RFC7752] | 549 | 1099 | Adjacency Segment | Section 2.2.1 | 550 | | Identifier (Adj-SID) TLV | | 551 | 1100 | LAN Adjacency Segment | Section 2.2.2 | 552 | | Identifier (Adj-SID) TLV | | 553 | 1104 | Unidirectional link delay | [I-D.ietf-idr-te-pm-bgp] | 554 | 1105 | Min/Max Unidirectional | [I-D.ietf-idr-te-pm-bgp] | 555 | | link delay | | 556 | 1106 | Min/Max Unidirectional | [I-D.ietf-idr-te-pm-bgp] | 557 | | link delay | | 558 | 1107 | Unidirectional packet loss | [I-D.ietf-idr-te-pm-bgp] | 559 | 1108 | Unidirectional residual | [I-D.ietf-idr-te-pm-bgp] | 560 | | bandwidth | | 561 | 1109 | Unidirectional available | [I-D.ietf-idr-te-pm-bgp] | 562 | | bandwidth | | 563 | 1110 | Unidirectional bandwidth | [I-D.ietf-idr-te-pm-bgp] | 564 | | utilization | | 565 +-----------+----------------------------+--------------------------+ 567 Table 3: L2 Bundle Member Link Attribute TLVs 569 2.3. Prefix Attribute TLVs 571 The following Prefix Attribute TLVs are defined: 573 +------------------------+----------+---------------+ 574 | Description | Length | Section | 575 +------------------------+----------+---------------+ 576 | Prefix SID | variable | Section 2.3.1 | 577 | Range | variable | Section 2.3.4 | 578 | Prefix Attribute Flags | variable | Section 2.3.2 | 579 | Source Router-ID | variable | Section 2.3.3 | 580 +------------------------+----------+---------------+ 582 Table 4: Prefix Attribute TLVs 584 2.3.1. Prefix-SID TLV 586 The Prefix-SID TLV can ONLY be added to the Prefix Attribute whose 587 local node in the corresponding Prefix NLRI is the node that 588 originates the corresponding SR TLV. 590 The Prefix-SID TLV is used in order to advertise information related 591 to a Prefix-SID. This information is originated in: 593 o IS-IS, as defined by the Prefix-SID TLV in 594 [I-D.ietf-isis-segment-routing-extensions]. 596 o OSPFv2/OSPFv3, as defined by the Prefix-SID TLV in 597 [I-D.ietf-ospf-segment-routing-extensions] and 598 [I-D.ietf-ospf-ospfv3-segment-routing-extensions]. 600 The Prefix-SID has the following format: 602 0 1 2 3 603 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 1 604 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 605 | Type | Length | 606 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 607 | Flags | Algorithm | Reserved | 608 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 609 | SID/Index/Label (variable) | 610 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 612 where: 614 Type: TBD, see Section 4. 616 Length: Variable, 7 or 8 depending on Label or Index encoding of 617 the SID 619 Algorithm: 1 octet value identify the algorithm. 621 Reserved: 2 octets that SHOULD be set to 0 and MUST be ignored on 622 receipt. 624 SID/Index/Label: 626 * IS-IS: Label or index value as defined in 627 [I-D.ietf-isis-segment-routing-extensions], 629 * OSPFv2: Label or index value as defined in 630 [I-D.ietf-ospf-segment-routing-extensions], 632 * OSPFv3: Label or index value as defined in 633 [I-D.ietf-ospf-ospfv3-segment-routing-extensions], 635 The Prefix-SID TLV includes a Flags field. In the context of BGP-LS, 636 the Flags field format and the semantic of each individual flag MUST 637 be taken from the corresponding source protocol (i.e.: the protocol 638 of origin of the Prefix-SID being advertised in BGP-LS). 640 IS-IS Prefix-SID flags are defined in 641 [I-D.ietf-isis-segment-routing-extensions] section 2.1. 643 OSPFv2 Prefix-SID flags are defined in 644 [I-D.ietf-ospf-segment-routing-extensions] section 5. 646 OSPFv3 Prefix-SID flags are defined in 647 [I-D.ietf-ospf-segment-routing-extensions] section 5. 649 2.3.2. Prefix Attribute Flags TLV 651 The Prefix Attribute Flags TLV carries IPv4/IPv6 prefix attribute 652 flags information. These flags are defined for OSPFv2 in [RFC7684], 653 for OSPFv3 in [RFC5340] and for ISIS in [RFC7794]. 655 The Prefix Attribute Flags TLV has the following format: 657 0 1 2 3 658 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 1 659 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 660 | Type | Length | 661 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 662 // Flags (variable) // 663 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 665 where: 667 Type: TBD, see Section 4. 669 Length: variable. 671 Flags: a variable length flag field (according to the length 672 field). Flags are routing protocol specific. OSPFv2 flags are 673 defined in [RFC7684], for OSPFv3 this maps to the Prefix Options 674 field defined in [RFC5340] and IS-IS flags are defined in 675 [RFC7794]. The receiver of the BGP-LS update, when inspecting the 676 Prefix Attribute Flags TLV, MUST check the Protocol-ID of the NLRI 677 and refer to the protocol specification in order to parse the 678 flags. 680 2.3.3. Source Router Identifier (Source Router-ID) TLV 682 The Source Router-ID TLV contains the IPv4 or IPv6 Router-ID of the 683 originator of the Prefix. For IS-IS protocol this is as defined in 684 [RFC7794]. The Source Router-ID TLV may be used to carry the OSPF 685 Router-ID of the prefix originator. 687 The Source Router-ID TLV has the following format: 689 0 1 2 3 690 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 1 691 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 692 | Type | Length | 693 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 694 // 4 or 6 octet Router-ID // 695 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 697 where: 699 Type: TBD, see Section 4. 701 Length: 4 or 16. 703 IPv4/IPv6 Address: 4 octet IPv4 address or 16 octet IPv6 address. 705 2.3.4. Range TLV 707 The Range TLV can ONLY be added to the Prefix Attribute whose local 708 node in the corresponding Prefix NLRI is the node that originates the 709 corresponding SR TLV. 711 When the range TLV is used in order to advertise a range of prefix- 712 to-SID mappings as defined in 713 [I-D.ietf-ospf-segment-routing-extensions], 714 [I-D.ietf-ospf-ospfv3-segment-routing-extensions] and 715 [I-D.ietf-isis-segment-routing-extensions]. The Prefix-NLRI the 716 Range TLV is attached to MUST be advertised as a non-routing prefix 717 where no IGP metric TLV (TLV 1095) is attached. 719 The format of the Range TLV is as follows: 721 0 1 2 3 722 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 1 723 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 724 | Type | Length | 725 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 726 | Flags | Reserved | Range Size | 727 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 728 // sub-TLVs // 729 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 731 where: 733 Figure 2: Range TLV format 735 Type: TBD, see Section 4. 737 Length: variable 739 Flags: as defined in [I-D.ietf-ospf-segment-routing-extensions], 740 [I-D.ietf-ospf-ospfv3-segment-routing-extensions] and 741 [I-D.ietf-isis-segment-routing-extensions]. 743 Reserved: 1 octet that SHOULD be set to 0 and MUST be ignored on 744 receipt. 746 Range Size: 2 octets as defined in 747 [I-D.ietf-ospf-segment-routing-extensions]. 749 Within the Range TLV, the prefix-to-SID mappings are advertised using 750 sub-TLVs as below: 752 2.3.4.1. Advertisement Procedure for OSPF 754 The OSPFv2/OSPFv3 Extended Prefix Range TLV is encoded in the Range 755 TLV. The flags of the Range TLV have the semantic mapped to the 756 definition in [I-D.ietf-ospf-segment-routing-extensions] section 4 or 757 [I-D.ietf-ospf-ospfv3-segment-routing-extensions] section 4. The 758 Prefix-SID from the original OSPF Prefix SID sub-TLV is encoded using 759 the BGP-LS Prefix Attribute Prefix-SID as defined in Section 2.3.1 760 with the flags set according to the definition in 761 [I-D.ietf-ospf-segment-routing-extensions] section 5 or 762 [I-D.ietf-ospf-ospfv3-segment-routing-extensions] section 5. 764 2.3.4.2. Advertisement Procedure for IS-IS 766 The advertisement of a range of IS-IS Mapping Server bindings 767 ([I-D.ietf-isis-segment-routing-extensions]) is encoded in the Range 768 TLV using the following TLV/sub-TLV structure: 770 Range TLV 771 Prefix-SID TLV (used as a sub-TLV in this context) 773 where: 775 o The Range TLV is defined in Section 2.3.4. 777 o The Prefix-SID TLV (used as sub-TLV in this context) is defined in 778 Section 2.3.1. 780 2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs 782 This section illustrate the IS-IS Segment Routing Extensions TLVs and 783 sub-TLVs mapped to the ones defined in this document. 785 The following table, illustrates for each BGP-LS TLV, its equivalence 786 in IS-IS. 788 +----------------------------------------+----------+---------------+ 789 | Description | Length | IS-IS TLV | 790 | | | /sub-TLV | 791 +----------------------------------------+----------+---------------+ 792 | SR Capabilities | variable | 2 [1] | 793 | SR Algorithm | variable | 19 [2] | 794 | Adjacency Segment Identifier (Adj-SID) | variable | 31 [3] | 795 | TLV | | | 796 | LAN Adjacency Segment Identifier (LAN- | variable | 32 [4] | 797 | Adj-SID) TLV | | | 798 | Prefix SID | variable | 3 [5] | 799 | SID/Label TLV | variable | 1 [6] | 800 | Prefix Attribute Flags | variable | 4 [7] | 801 | Source Router ID | variable | 11/12 [8] | 802 | L2 Bundle Member TLV | variable | 25 [9] | 803 +----------------------------------------+----------+---------------+ 805 Table 5: IS-IS Segment Routing Extensions TLVs/Sub-TLVs 807 2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs 809 This section illustrate the OSPFv2 and OSPFv3 Segment Routing 810 Extensions TLVs and sub-TLVs mapped to the ones defined in this 811 document. 813 The following table, illustrates for each BGP-LS TLV, its equivalence 814 in OSPFv2 and OSPFv3. 816 +--------------------------------------+----------+-----------------+ 817 | Description | Length | OSPFv2 TLV/sub- | 818 | | | TLV | 819 +--------------------------------------+----------+-----------------+ 820 | SR Capabilities | variable | 9 [10] | 821 | SR Algorithm | variable | 8 [11] | 822 | Adjacency Segment Identifier (Adj- | variable | 2 [12] | 823 | SID) TLV | | | 824 | LAN Adjacency Segment Identifier | variable | 3 [13] | 825 | (Adj-SID) TLV | | | 826 | Prefix SID | variable | 2 [14] | 827 | SID/Label TLV | variable | 1 [15] | 828 | Prefix Attribute Flags | variable | 4 [16] | 829 +--------------------------------------+----------+-----------------+ 831 Table 6: OSPF Segment Routing Extensions TLVs/Sub-TLVs 833 +--------------------------------------+----------+-----------------+ 834 | Description | Length | OSPFv3 TLV/sub- | 835 | | | TLV | 836 +--------------------------------------+----------+-----------------+ 837 | SR Capabilities | variable | 9 [17] | 838 | SR Algorithm | variable | 8 [18] | 839 | Adjacency Segment Identifier (Adj- | variable | 5 [19] | 840 | SID) TLV | | | 841 | LAN Adjacency Segment Identifier | variable | 6 [20] | 842 | (Adj-SID) TLV | | | 843 | Prefix SID | variable | 4 [21] | 844 | SID/Label TLV | variable | 3 [22] | 845 | Prefix Attribute Flags | variable | 4 [23] | 846 +--------------------------------------+----------+-----------------+ 848 Table 7: OSPFv3 Segment Routing Extensions TLVs/Sub-TLVs 850 3. Implementation Status 852 Note to RFC Editor: Please remove this section prior to publication, 853 as well as the reference to RFC 7942. 855 This section records the status of known implementations of the 856 protocol defined by this specification at the time of posting of this 857 Internet-Draft, and is based on a proposal described in [RFC7942]. 858 The description of implementations in this section is intended to 859 assist the IETF in its decision processes in progressing drafts to 860 RFCs. Please note that the listing of any individual implementation 861 here does not imply endorsement by the IETF. Furthermore, no effort 862 has been spent to verify the information presented here that was 863 supplied by IETF contributors. This is not intended as, and must not 864 be construed to be, a catalog of available implementations or their 865 features. Readers are advised to note that other implementations may 866 exist. 868 According to [RFC7942], "this will allow reviewers and working groups 869 to assign due consideration to documents that have the benefit of 870 running code, which may serve as evidence of valuable experimentation 871 and feedback that have made the implemented protocols more mature. 872 It is up to the individual working groups to use this information as 873 they see fit". 875 Several early implementations exist and will be reported in detail in 876 a forthcoming version of this document. For purposes of early 877 interoperability testing, when no FCFS code point was available, 878 implementations have made use of the values described in Table 8. 880 It will ease implementation interoperability and deployment if the 881 value could be preserved also due to the large amount of codepoints 882 this draft requires. However, when IANA-assigned values are 883 available, implementations will be updated to use them. 885 4. IANA Considerations 887 This document requests assigning code-points from the registry "BGP- 888 LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute 889 TLVs" based on table Table 8. The column "IS-IS TLV/Sub-TLV" defined 890 in the registry does not require any value and should be left empty. 892 4.1. TLV/Sub-TLV Code Points Summary 894 This section contains the global table of all TLVs/sub-TLVs defined 895 in this document. 897 +-------------+-------------------------------------+---------------+ 898 | TLV Code | Description | Reference | 899 | Point | | | 900 +-------------+-------------------------------------+---------------+ 901 | 1034 | SR Capabilities | Section 2.1.2 | 902 | 1035 | SR Algorithm | Section 2.1.3 | 903 | 1036 | SR Local Block | Section 2.1.4 | 904 | 1037 | SRMS Preference | Section 2.1.5 | 905 | 1099 | Adjacency Segment Identifier (Adj- | Section 2.2.1 | 906 | | SID) TLV | | 907 | 1100 | LAN Adjacency Segment Identifier | Section 2.2.2 | 908 | | (Adj-SID) TLV | | 909 | 1158 | Prefix SID | Section 2.3.1 | 910 | 1159 | Range | Section 2.3.4 | 911 | 1161 | SID/Label TLV | Section 2.1.1 | 912 | 1170 | Prefix Attribute Flags | Section 2.3.2 | 913 | 1171 | Source Router-ID | Section 2.3.3 | 914 | 1172 | L2 Bundle Member TLV | Section 2.2.3 | 915 +-------------+-------------------------------------+---------------+ 917 Table 8: Summary Table of TLV/Sub-TLV Codepoints 919 5. Manageability Considerations 921 This section is structured as recommended in [RFC5706]. 923 The new protocol extensions introduced in this document augment the 924 existing IGP topology information that was distributed via [RFC7752]. 925 Procedures and protocol extensions defined in this document do not 926 affect the BGP protocol operations and management other than as 927 discussed in the Manageability Considerations section of [RFC7752]. 929 5.1. Operational Considerations 931 No additional operation considerations are defined in this document. 933 5.2. Management Considerations 935 No additional management considerations are defined in this document. 937 6. Security Considerations 939 The new protocol extensions introduced in this document augment the 940 existing IGP topology information that was distributed via [RFC7752]. 941 Procedures and protocol extensions defined in this document do not 942 affect the BGP security model other than as discussed in the Security 943 Considerations section of [RFC7752]. 945 7. Contributors 947 The following people have substantially contributed to the editing of 948 this document: 950 Peter Psenak 951 Cisco Systems 952 Email: ppsenak@cisco.com 954 Les Ginsberg 955 Cisco Systems 956 Email: ginsberg@cisco.com 958 Acee Lindem 959 Cisco Systems 960 Email: acee@cisco.com 962 Saikat Ray 963 Individual 964 Email: raysaikat@gmail.com 966 Jeff Tantsura 967 Nuage Networks 968 Email: jefftant.ietf@gmail.com 970 8. Acknowledgements 972 The authors would like to thank Jeffrey Haas and Aijun Wang for their 973 review of this document and their comments. 975 9. References 977 9.1. Normative References 979 [I-D.ietf-idr-te-pm-bgp] 980 Ginsberg, L., Previdi, S., Wu, Q., Tantsura, J., and C. 981 Filsfils, "BGP-LS Advertisement of IGP Traffic Engineering 982 Performance Metric Extensions", draft-ietf-idr-te-pm- 983 bgp-10 (work in progress), March 2018. 985 [I-D.ietf-isis-segment-routing-extensions] 986 Previdi, S., Ginsberg, L., Filsfils, C., Bashandy, A., 987 Gredler, H., Litkowski, S., Decraene, B., and J. Tantsura, 988 "IS-IS Extensions for Segment Routing", draft-ietf-isis- 989 segment-routing-extensions-16 (work in progress), April 990 2018. 992 [I-D.ietf-ospf-ospfv3-segment-routing-extensions] 993 Psenak, P., Filsfils, C., Previdi, S., Gredler, H., 994 Shakir, R., Henderickx, W., and J. Tantsura, "OSPFv3 995 Extensions for Segment Routing", draft-ietf-ospf-ospfv3- 996 segment-routing-extensions-12 (work in progress), April 997 2018. 999 [I-D.ietf-ospf-segment-routing-extensions] 1000 Psenak, P., Previdi, S., Filsfils, C., Gredler, H., 1001 Shakir, R., Henderickx, W., and J. Tantsura, "OSPF 1002 Extensions for Segment Routing", draft-ietf-ospf-segment- 1003 routing-extensions-25 (work in progress), April 2018. 1005 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1006 Requirement Levels", BCP 14, RFC 2119, 1007 DOI 10.17487/RFC2119, March 1997, 1008 . 1010 [RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions 1011 in Support of Generalized Multi-Protocol Label Switching 1012 (GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005, 1013 . 1015 [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF 1016 for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008, 1017 . 1019 [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., 1020 Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute 1021 Advertisement", RFC 7684, DOI 10.17487/RFC7684, November 1022 2015, . 1024 [RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and 1025 S. Ray, "North-Bound Distribution of Link-State and 1026 Traffic Engineering (TE) Information Using BGP", RFC 7752, 1027 DOI 10.17487/RFC7752, March 2016, 1028 . 1030 [RFC7794] Ginsberg, L., Ed., Decraene, B., Previdi, S., Xu, X., and 1031 U. Chunduri, "IS-IS Prefix Attributes for Extended IPv4 1032 and IPv6 Reachability", RFC 7794, DOI 10.17487/RFC7794, 1033 March 2016, . 1035 9.2. Informative References 1037 [I-D.ietf-spring-segment-routing] 1038 Filsfils, C., Previdi, S., Ginsberg, L., Decraene, B., 1039 Litkowski, S., and R. Shakir, "Segment Routing 1040 Architecture", draft-ietf-spring-segment-routing-15 (work 1041 in progress), January 2018. 1043 [RFC5706] Harrington, D., "Guidelines for Considering Operations and 1044 Management of New Protocols and Protocol Extensions", 1045 RFC 5706, DOI 10.17487/RFC5706, November 2009, 1046 . 1048 [RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running 1049 Code: The Implementation Status Section", BCP 205, 1050 RFC 7942, DOI 10.17487/RFC7942, July 2016, 1051 . 1053 9.3. URIs 1055 [1] http://tools.ietf.org/html/draft-ietf-isis-segment-routing- 1056 extensions-05#section-3.1 1058 [2] http://tools.ietf.org/html/draft-ietf-isis-segment-routing- 1059 extensions-05#section-3.2 1061 [3] http://tools.ietf.org/html/draft-ietf-isis-segment-routing- 1062 extensions-05#section-2.2.1 1064 [4] http://tools.ietf.org/html/draft-ietf-isis-segment-routing- 1065 extensions-05#section-2.2.2 1067 [5] http://tools.ietf.org/html/draft-ietf-isis-segment-routing- 1068 extensions-05#section-2.1 1070 [6] http://tools.ietf.org/html/draft-ietf-isis-segment-routing- 1071 extensions-05#section-2.3 1073 [7] http://tools.ietf.org/html/RFC7794 1075 [8] http://tools.ietf.org/html/RFC7794 1077 [9] http://tools.ietf.org/html/draft-ietf-isis-l2bundles-05 1079 [10] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing- 1080 extensions-05#section-3.2 1082 [11] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing- 1083 extensions-05#section-3.1 1085 [12] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing- 1086 extensions-05#section-7.1 1088 [13] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing- 1089 extensions-05#section-7.2 1091 [14] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing- 1092 extensions-05#section-5 1094 [15] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing- 1095 extensions-05#section-2.1 1097 [16] http://tools.ietf.org/html/RFC7684#section-2.1 1099 [17] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment- 1100 routing-extensions-05#section-3.2 1102 [18] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment- 1103 routing-extensions-05#section-3.1 1105 [19] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment- 1106 routing-extensions-05#section-7.1 1108 [20] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment- 1109 routing-extensions-05#section-7.2 1111 [21] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment- 1112 routing-extensions-05#section-5 1114 [22] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment- 1115 routing-extensions-05#section-2.1 1117 [23] http://tools.ietf.org/html/RFC5340#section-A.4.1.1 1119 Authors' Addresses 1121 Stefano Previdi (editor) 1122 Via Del Serafico, 200 1123 Rome 00142 1124 Italy 1126 Email: stefano@previdi.net 1127 Ketan Talaulikar 1128 Cisco Systems, Inc. 1129 S.No. 154/6, Phase I, Hinjawadi 1130 Pune 411 057 1131 India 1133 Email: ketant@cisco.com 1135 Clarence Filsfils 1136 Cisco Systems, Inc. 1137 Brussels 1138 Belgium 1140 Email: cfilsfil@cisco.com 1142 Hannes Gredler 1143 RtBrick Inc. 1145 Email: hannes@rtbrick.com 1147 Mach(Guoyi) Chen 1148 Huawei Technologies 1149 Huawei Building, No. 156 Beiqing Rd. 1150 Beijing 100095 1151 China 1153 Email: mach.chen@huawei.com