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Filsfils 4 Intended status: Standards Track Cisco Systems, Inc. 5 Expires: June 5, 2016 S. Ray 6 Individual Contributor 7 K. Patel 8 Cisco Systems, Inc. 9 J. Dong 10 M. Chen 11 Huawei Technologies 12 December 3, 2015 14 Segment Routing Egress Peer Engineering BGP-LS Extensions 15 draft-ietf-idr-bgpls-segment-routing-epe-01 17 Abstract 19 Segment Routing (SR) leverages source routing. A node steers a 20 packet through a controlled set of instructions, called segments, by 21 prepending the packet with an SR header. A segment can represent any 22 instruction, topological or service-based. SR allows to enforce a 23 flow through any topological path and service chain while maintaining 24 per-flow state only at the ingress node of the SR domain. 26 The Segment Routing architecture can be directly applied to the MPLS 27 dataplane with no change on the forwarding plane. It requires minor 28 extension to the existing link-state routing protocols. 30 This document outline a BGP-LS extension for exporting BGP egress 31 point topology information (including its peers, interfaces and 32 peering ASs) in a way that is exploitable in order to compute 33 efficient Egress Point Engineering policies and strategies. 35 Requirements Language 37 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 38 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 39 document are to be interpreted as described in RFC 2119 [RFC2119]. 41 Status of This Memo 43 This Internet-Draft is submitted in full conformance with the 44 provisions of BCP 78 and BCP 79. 46 Internet-Drafts are working documents of the Internet Engineering 47 Task Force (IETF). Note that other groups may also distribute 48 working documents as Internet-Drafts. The list of current Internet- 49 Drafts is at http://datatracker.ietf.org/drafts/current/. 51 Internet-Drafts are draft documents valid for a maximum of six months 52 and may be updated, replaced, or obsoleted by other documents at any 53 time. It is inappropriate to use Internet-Drafts as reference 54 material or to cite them other than as "work in progress." 56 This Internet-Draft will expire on June 5, 2016. 58 Copyright Notice 60 Copyright (c) 2015 IETF Trust and the persons identified as the 61 document authors. All rights reserved. 63 This document is subject to BCP 78 and the IETF Trust's Legal 64 Provisions Relating to IETF Documents 65 (http://trustee.ietf.org/license-info) in effect on the date of 66 publication of this document. Please review these documents 67 carefully, as they describe your rights and restrictions with respect 68 to this document. Code Components extracted from this document must 69 include Simplified BSD License text as described in Section 4.e of 70 the Trust Legal Provisions and are provided without warranty as 71 described in the Simplified BSD License. 73 Table of Contents 75 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 76 2. Segment Routing Documents . . . . . . . . . . . . . . . . . . 3 77 3. BGP Peering Segments . . . . . . . . . . . . . . . . . . . . 3 78 4. Link NLRI for EPE Connectivity Description . . . . . . . . . 4 79 4.1. BGP Router ID and Member ASN . . . . . . . . . . . . . . 5 80 4.2. EPE Node Descriptors . . . . . . . . . . . . . . . . . . 5 81 4.3. Link Attributes . . . . . . . . . . . . . . . . . . . . . 6 82 5. Peer Node and Peer Adjacency Segments . . . . . . . . . . . . 8 83 5.1. Peer Node Segment (Peer-Node-SID) . . . . . . . . . . . . 9 84 5.2. Peer Adjacency Segment (Peer-Adj-SID) . . . . . . . . . . 10 85 5.3. Peer Set Segment . . . . . . . . . . . . . . . . . . . . 11 86 6. Illustration . . . . . . . . . . . . . . . . . . . . . . . . 11 87 6.1. Reference Diagram . . . . . . . . . . . . . . . . . . . . 11 88 6.1.1. Peer Node Segment for Node D . . . . . . . . . . . . 13 89 6.1.2. Peer Node Segment for Node H . . . . . . . . . . . . 14 90 6.1.3. Peer Node Segment for Node E . . . . . . . . . . . . 14 91 6.1.4. Peer Adjacency Segment for Node E, Link 1 . . . . . . 14 92 6.1.5. Peer Adjacency Segment for Node E, Link 2 . . . . . . 15 93 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 94 8. Manageability Considerations . . . . . . . . . . . . . . . . 16 95 9. Security Considerations . . . . . . . . . . . . . . . . . . . 16 96 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 16 97 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16 98 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 99 12.1. Normative References . . . . . . . . . . . . . . . . . . 16 100 12.2. Informative References . . . . . . . . . . . . . . . . . 17 101 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 103 1. Introduction 105 Segment Routing (SR) leverages source routing. A node steers a 106 packet through a controlled set of instructions, called segments, by 107 prepending the packet with an SR header. A segment can represent any 108 instruction, topological or service-based. SR allows to enforce a 109 flow through any topological path and service chain while maintaining 110 per-flow state only at the ingress node of the SR domain. 112 The Segment Routing architecture can be directly applied to the MPLS 113 dataplane with no change on the forwarding plane. It requires minor 114 extension to the existing link-state routing protocols. 116 This document outline a BGP-LS extension for exporting BGP egress 117 point topology information (including its peers, interfaces and 118 peering ASs) in a way that is exploitable in order to compute 119 efficient Egress Point Engineering policies and strategies. 121 This document defines new types of segments: a Peer Node segment 122 describing the BGP session between two nodes; a Peer Adjacency 123 Segment describing the link (one or more) that is used by the BGP 124 session; the Peer Set Segment describing an arbitrary set of sessions 125 or links between the local BGP node and its peers. 127 2. Segment Routing Documents 129 The main reference for this document is the SR architecture defined 130 in [I-D.ietf-spring-segment-routing]. 132 The Segment Routing Egress Peer Engineering architecture is described 133 in [I-D.filsfils-spring-segment-routing-central-epe]. 135 3. BGP Peering Segments 137 As defined in [draft-filsfils-spring-segment-routing-epe], an EPE 138 enabled Egress PE node MAY advertise segments corresponding to its 139 attached peers. These segments are called BGP peering segments or 140 BGP Peering SIDs. They enable the expression of source-routed inter- 141 domain paths. 143 An ingress border router of an AS may compose a list of segments to 144 steer a flow along a selected path within the AS, towards a selected 145 egress border router C of the AS and through a specific peer. At 146 minimum, a BGP Peering Engineering policy applied at an ingress PE 147 involves two segments: the Node SID of the chosen egress PE and then 148 the BGP Peering Segment for the chosen egress PE peer or peering 149 interface. 151 This document defines the BGP EPE Peering Segments: 153 o Peer Node Segment (Peer-Node-SID) 155 o Peer Adjacency Segment (Peer-Adj-SID) 157 o Peer Set Segment (Peer-Set-SID) 159 Each BGP session MUST be described by a Peer Node Segment. The 160 description of the BGP session MAY be augmented by additional 161 Adjacency Segments. Finally, each Peer Node Segment and Peer 162 Adjacency Segment MAY be part of the same group/set so to be able to 163 group EPE resources under a common Peer-Set Segment Identifier (SID). 165 Therefore, when the extensions defined in this document are applied 166 to the use case defined in 167 [I-D.filsfils-spring-segment-routing-central-epe]: 169 o One Peer Node Segment MUST be present. 171 o One or more Peer Adjacency Segments MAY be present. 173 o Each of the Peer Node and Peer Adjacency Segment MAY use the same 174 Peer-Set. 176 4. Link NLRI for EPE Connectivity Description 178 This section describes the NLRI used for describing the connectivity 179 of the BGP Egress router. The connectivity is based on links and 180 remote peers/ASs and therefore the existing Link-Type NLRI (defined 181 in [I-D.ietf-idr-ls-distribution]) is used. A new Protocol ID is 182 used (codepoint to be assigned by IANA, suggested value 7). 184 The use of a new Protocol-ID allows separation and differentiation 185 between the NLRIs carrying BGP-EPE descriptors from the NLRIs 186 carrying IGP link-state information as defined 187 in[I-D.ietf-idr-ls-distribution]. The Link NLRI Type uses 188 descriptors and attributes already defined in 189 [I-D.ietf-idr-ls-distribution] in addition to new TLVs defined in the 190 following sections of this document. 192 The format of the Link NLRI Type is as follows: 194 0 1 2 3 195 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 1 196 +-+-+-+-+-+-+-+-+ 197 | Protocol-ID | 198 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 199 | Identifier | 200 | (64 bits) | 201 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 202 // Local Node Descriptors // 203 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 204 // Remote Node Descriptors // 205 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 206 // Link Descriptors // 207 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 209 Node Descriptors and Link Descriptors are defined in 210 [I-D.ietf-idr-ls-distribution]. 212 4.1. BGP Router ID and Member ASN 214 Two new Node Descriptors Sub-TLVs are defined in this document: 216 o BGP Router Identifier (BGP Router-ID): 218 Type: TBA (suggested value 516). 220 Length: 4 octets 222 Value: 4 octet unsigned integer representing the BGP Identifier 223 as defined in [RFC4271] and [RFC6286]. 225 o Confederation Member ASN (Member-ASN) 227 Type: TBA (suggested value 517). 229 Length: 4 octets 231 Value: 4 octet unsigned integer representing the Member ASN 232 inside the Confederation.[RFC5065]. 234 4.2. EPE Node Descriptors 236 The following Node Descriptors Sub-TLVs MUST appear in the Link NLRI 237 as Local Node Descriptors: 239 o BGP Router ID, which contains the BGP Identifier of the local BGP 240 EPE node. 242 o Autonomous System Number, which contains the local ASN or local 243 confederation identifier (ASN) if confederations are used. 245 o BGP-LS Identifier. 247 It has to be noted that [RFC6286] (section 2.1) requires the BGP 248 identifier (router-id) to be unique within an Autonomous System. 249 Therefore, the tuple is globally unique. 251 The following Node Descriptors Sub-TLVs MAY appear in the Link NLRI 252 as Local Node Descriptors: 254 o Member-ASN, which contains the ASN of the confederation member 255 (when BGP confederations are used). 257 o Node Descriptors as defined in [I-D.ietf-idr-ls-distribution]. 259 The following Node Descriptors Sub-TLVs MUST appear in the Link NLRI 260 as Remote Node Descriptors: 262 o BGP Router ID, which contains the BGP Identifier of the peer node. 264 o Autonomous System Number, which contains the peer ASN or the peer 265 confederation identifier (ASN), if confederations are used. 267 The following Node Descriptors Sub-TLVs MAY appear in the Link NLRI 268 as Remote Node Descriptors: 270 o Member-ASN, which contains the ASN of the confederation member 271 (when BGP confederations are used). 273 o Node Descriptors as defined in defined in 274 [I-D.ietf-idr-ls-distribution]. 276 4.3. Link Attributes 278 The following BGP-LS Link attributes TLVs are used with the Link 279 NLRI: 281 +----------+---------------------------+----------+ 282 | TLV Code | Description | Length | 283 | Point | | | 284 +----------+---------------------------+----------+ 285 | 1101 | Peer Node Segment | variable | 286 | | Identifier (Peer-Node-SID)| | 287 | 1102 | Peer Adjacency Segment | variable | 288 | | Identifier (Peer-Adj-SID) | | 289 | 1103 | Peer Set Segment | variable | 290 | | Identifier (Peer-Set-SID) | | 291 +----------+---------------------------+----------+ 293 Figure 1: TLV code points for BGP-LS EPE 295 Peer-Node-SID, Peer-Adj-SID and Peer-Set-SID have all the same format 296 defined here below: 298 0 1 2 3 299 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 1 300 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 301 | Type | Length | 302 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 303 | Flags | Weight | Reserved | 304 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 305 | SID/Label/Index (variable) | 306 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 308 where: 310 Figure 2 312 o Type: To be assigned by IANA. The suggested values are defined in 313 Figure 1. 315 o Length: variable. 317 o Flags: following flags have been defined: 319 0 1 2 3 4 5 6 7 320 +-+-+-+-+-+-+-+-+ 321 |V|L| | 322 +-+-+-+-+-+-+-+-+ 324 where: 326 * V-Flag: Value flag. If set, then the Adj-SID carries a value. 327 By default the flag is SET. 329 * L-Flag: Local Flag. If set, then the value/index carried by 330 the Adj-SID has local significance. By default the flag is 331 SET. 333 * Other bits: MUST be zero when originated and ignored when 334 received. 336 o Weight: 1 octet. The value represents the weight of the SID for 337 the purpose of load balancing. An example use of the weight is 338 described in [I-D.ietf-spring-segment-routing]. 340 o SID/Index/Label. According to the TLV length and to the V and L 341 flags settings, it contains either: 343 * A 3 octet local label where the 20 rightmost bits are used for 344 encoding the label value. In this case the V and L flags MUST 345 be set. 347 * A 4 octet index defining the offset in the SID/Label space 348 advertised by this router using the encodings defined in 349 Section 3.1. In this case V and L flags MUST be unset. 351 * A 16 octet IPv6 address. In this case the V flag MUST be set. 352 The L flag MUST be unset if the IPv6 address is globally 353 unique. 355 The values of the Peer-Node-SID, Peer-Adj-SID and Peer-Set-SID Sub- 356 TLVs SHOULD be persistent across router restart. 358 The Peer-Node-SID MUST be present when BGP-LS is used for the use 359 case described in [I-D.filsfils-spring-segment-routing-central-epe] 360 and MAY be omitted for other use cases. 362 The Peer-Adj-SID and Peer-Set-SID SubTLVs MAY be present when BGP-LS 363 is used for the use case described in 364 [I-D.filsfils-spring-segment-routing-central-epe] and MAY be omitted 365 for other use cases. 367 In addition, BGP-LS Nodes and Link Attributes, as defined in 368 [I-D.ietf-idr-ls-distribution]MAY be inserted in order to advertise 369 the characteristics of the link. 371 5. Peer Node and Peer Adjacency Segments 373 In this section the following Peer Segments are defined: 375 Peer Node Segment (Peer-Node-SID) 376 Peer Adjacency Segment (Peer-Adj-SID) 378 Peer Set Segment (Peer-Set-SID) 380 The Peer Node, Peer Adjacency and Peer Set segments can be either a 381 local or a global segment (depending on the setting of the V and L 382 flags defined in Figure 2. For example, when EPE is used in the 383 context of a SR network over the IPv6 dataplane, it is likely the 384 case that the IPv6 addresses used as SIDs will be global. 386 5.1. Peer Node Segment (Peer-Node-SID) 388 The Peer Node Segment describes the BGP session peer (neighbor). It 389 MUST be present when describing an EPE topology as defined in 390 [I-D.filsfils-spring-segment-routing-central-epe]. The Peer Node 391 Segment is encoded within the BGP-LS Link NLRI specified in 392 Section 4. 394 The Peer Node Segment, at the BGP node advertising it, has the 395 following semantic: 397 o SR header operation: NEXT (as defined in 398 [I-D.ietf-spring-segment-routing]). 400 o Next-Hop: the connected peering node to which the segment is 401 related. 403 The Peer Node Segment is advertised with a Link NLRI, where: 405 o Local Node Descriptors contains 407 Local BGP Router ID of the EPE enabled egress PE. 408 Local ASN. 409 BGP-LS Identifier. 411 o Remote Node Descriptors contains 413 Peer BGP Router ID (i.e.: the peer BGP ID used in the BGP session). 414 Peer ASN. 416 o Link Descriptors Sub-TLVs, as defined in 417 [I-D.ietf-idr-ls-distribution], contain the addresses used by the 418 BGP session: 420 * IPv4 Interface Address (Sub-TLV 259) contains the BGP session 421 IPv4 local address. 423 * IPv4 Neighbor Address (Sub-TLV 260) contains the BGP session 424 IPv4 peer address. 426 * IPv6 Interface Address (Sub-TLV 261) contains the BGP session 427 IPv6 local address. 429 * IPv6 Neighbor Address (Sub-TLV 262) contains the BGP session 430 IPv6 peer address. 432 o Link Attribute contains the Peer-Node-SID TLV as defined in 433 Section 4.3. 435 o In addition, BGP-LS Link Attributes, as defined in 436 [I-D.ietf-idr-ls-distribution], MAY be inserted in order to 437 advertise the characteristics of the link. 439 5.2. Peer Adjacency Segment (Peer-Adj-SID) 441 The Peer Adjacency Segment, at the BGP node advertising it, has the 442 following semantic: 444 o SR header operation: NEXT (as defined in 445 [I-D.ietf-spring-segment-routing]). 447 o Next-Hop: the interface peer address. 449 The Peer Adjacency Segment is advertised with a Link NLRI, where: 451 o Local Node Descriptors contains 453 Local BGP Router ID of the EPE enabled egress PE. 454 Local ASN. 455 BGP-LS Identifier. 457 o Remote Node Descriptors contains 459 Peer BGP Router ID (i.e.: the peer BGP ID used in the BGP session). 460 Peer ASN. 462 o Link Descriptors Sub-TLVs, as defined in 463 [I-D.ietf-idr-ls-distribution], MUST contain the following TLVs: 465 * Link Local/Remote Identifiers (Sub-TLV 258) contains the 466 4-octet Link Local Identifier followed by the 4-octet value 0 467 indicating the Link Remote Identifier in unknown [RFC5307]. 469 o In addition, Link Descriptors Sub-TLVs, as defined in 470 [I-D.ietf-idr-ls-distribution], MAY contain the following TLVs: 472 * IPv4 Interface Address (Sub-TLV 259) contains the address of 473 the local interface through which the BGP session is 474 established. 476 * IPv6 Interface Address (Sub-TLV 261) contains the address of 477 the local interface through which the BGP session is 478 established. 480 * IPv4 Neighbor Address (Sub-TLV 260) contains the IPv4 address 481 of the peer interface used by the BGP session. 483 * IPv6 Neighbor Address (Sub-TLV 262) contains the IPv6 address 484 of the peer interface used by the BGP session. 486 o Link attribute used with the Peer-Adj-SID contains the TLV as 487 defined in Section 4.3. 489 In addition, BGP-LS Link Attributes, as defined in 490 [I-D.ietf-idr-ls-distribution], MAY be inserted in order to advertise 491 the characteristics of the link. 493 5.3. Peer Set Segment 495 The Peer Adjacency Segment, at the BGP node advertising it, has the 496 following semantic: 498 o SR header operation: NEXT (as defined in 499 [I-D.ietf-spring-segment-routing]). 501 o Next-Hop: load balance across any connected interface to any peer 502 in the related set. 504 The Peer Set Segment is advertised within a Link NLRI (describing a 505 Peer Node Segment or a Peer Adjacency segment) as a BGP-LS attribute. 507 The Peer Set Attribute contains the Peer-Set-SID TLV, defined in 508 Section 4.3 identifying the set of which the Peer Node Segment or 509 Peer Adjacency Segment is a member. 511 6. Illustration 513 6.1. Reference Diagram 515 The following reference diagram is used throughout this document. 516 The solution is described for IPv4 with MPLS-based segments. 518 +------+ 519 | | 520 +---D F 521 +---------+ / | AS 2 |\ +------+ 522 | X |/ +------+ \ | Z |---L/8 523 A C---+ \| | 524 | |\\ \ +------+ /| AS 4 |---M/8 525 | AS1 | \\ +-H |/ +------+ 526 | | \\ | G 527 +----P----+ +===E AS 3 | 528 | +--Q---+ 529 | | 530 +----------------+ 532 Figure 3: Reference Diagram 534 IPv4 addressing: 536 o C's IPv4 address of interface to D: 1.0.1.1/24, D's interface: 537 1.0.1.2/24 539 o C's IPv4 address of interface to H: 1.0.2.1/24, H's interface: 540 1.0.2.2/24 542 o C's IPv4 address of upper interface to E: 1.0.3.1, E's interface: 543 1.0.3.2/24 545 o C's local identifier of upper interface to E: 0.0.0.1.0.0.0.0 547 o C's IPv4 address of lower interface to E: 1.0.4.1/24, E's 548 interface: 1.0.4.2/24 550 o C's local identifier of lower interface to E: 0.0.0.2.0.0.0.0 552 o Loopback of E used for eBGP multi-hop peering to C: 1.0.5.2/32 554 o C's loopback is 3.3.3.3/32 with SID 64 556 BGP Router-IDs are C, D, H and E. 558 o C's BGP Router-ID: 3.3.3.3 560 o D's BGP Router-ID: 4.4.4.4 562 o E's BGP Router-ID: 5.5.5.5 564 o H's BGP Router-ID: 6.6.6.6 565 C's BGP peering: 567 o Single-hop eBGP peering with neighbor 1.0.1.2 (D) 569 o Single-hop eBGP peering with neighbor 1.0.2.2 (H) 571 o Multi-hop eBGP peering with E on ip address 1.0.5.2 (E) 573 C's resolution of the multi-hop eBGP session to E: 575 o Static route 1.0.5.2/32 via 1.0.3.2 577 o Static route 1.0.5.2/32 via 1.0.4.2 579 Node C configuration is such that: 581 o A Peer Node segment (Peer-Node-SID) is allocated to each peer (D, 582 H and E). 584 o An Peer Adjacency segment (Peer-Adj-SID) is defined for each 585 recursing interface to a multi-hop peer (CE upper and lower 586 interfaces). 588 o A Peer Set segment (Peer-Set-SID) is defined to include all peers 589 in AS3 (peers H and E). 591 Local BGP-LS Identifier in router C is set to 10000. 593 The Link NLRI Type is used in order to encode C's connectivity. the 594 Link NLRI uses the new Protocol-ID value (to be assigned by IANA). 596 6.1.1. Peer Node Segment for Node D 598 Descriptors: 600 o Local Node Descriptors (BGP Router-ID, local ASN, BGP-LS 601 Identifier): 3.3.3.3 , AS1, 10000 603 o Remote Node Descriptors (BGP Router-ID, peer ASN): 4.4.4.4, AS2 605 o Link Descriptors (BGP session IPv4 local address, BGP session IPv4 606 neighbor address): 1.0.1.1, 1.0.1.2 608 Attributes: 610 o Peer-Node-SID: 1012 611 o Link Attributes: see section 3.3.2 of 612 [I-D.ietf-idr-ls-distribution] 614 6.1.2. Peer Node Segment for Node H 616 Descriptors: 618 o Local Node Descriptors (BGP Router-ID, ASN, BGPL Identifier): 619 3.3.3.3 , AS1, 10000 621 o Remote Node Descriptors (BGP Router-ID ASN): 6.6.6.6, AS3 623 o Link Descriptors (BGP session IPv4 local address, BGP session IPv4 624 peer address): 1.0.2.1, 1.0.2.2 626 Attributes: 628 o Peer-Node-SID: 1022 630 o Peer-Set-SID: 1060 632 o Link Attributes: see section 3.3.2 of 633 [I-D.ietf-idr-ls-distribution] 635 6.1.3. Peer Node Segment for Node E 637 Descriptors: 639 o Local Node Descriptors (BGP Router-ID, ASN, BGP-LS Identifier): 640 3.3.3.3 , AS1, 10000 642 o Remote Node Descriptors (BGP Router-ID, ASN): 5.5.5.5, AS3 644 o Link Descriptors (BGP session IPv4 local address, BGP session IPv4 645 peer address): 3.3.3.3, 1.0.5.2 647 Attributes: 649 o Peer-Node-SID: 1052 651 o Peer-Set-SID: 1060 653 6.1.4. Peer Adjacency Segment for Node E, Link 1 655 Descriptors: 657 o Local Node Descriptors (BGP Router-ID, ASN, BGP-LS Identifier): 658 3.3.3.3 , AS1, 10000 660 o Remote Node Descriptors (BGP Router-ID, ASN): 5.5.5.5, AS3 662 o Link Descriptors (local interface identifier, IPv4 peer interface 663 address): 0.0.0.1.0.0.0.0 , 1.0.3.2 665 Attributes: 667 o Peer-Adj-SID: 1032 669 o LinkAttributes: see section 3.3.2 of 670 [I-D.ietf-idr-ls-distribution] 672 6.1.5. Peer Adjacency Segment for Node E, Link 2 674 Descriptors: 676 o Local Node Descriptors (BGP Router-ID, ASN, BGP-LS Identifier): 677 3.3.3.3 , AS1, 10000 679 o Remote Node Descriptors (BGP Router-ID, ASN): 5.5.5.5, AS3 681 o Link Descriptors (local interface identifier, IPv4 peer interface 682 address): 0.0.0.2.0.0.0.0 , 1.0.4.2 684 Attributes: 686 o Peer-Adj-SID: 1042 688 o LinkAttributes: see section 3.3.2 of 689 [I-D.ietf-idr-ls-distribution] 691 7. IANA Considerations 693 This document defines: 695 Two new Node Descriptors Sub-TLVs: BGP-Router-ID and BGP 696 Confederation Member. 698 A new Protocol-ID for EPE: BGP-EPE. 700 Three new BGP-LS Attribute Sub-TLVs: Peer-Node-SID, Peer-Adj-SID 701 and Peer-Set-SID. 703 The codepoints are to be assigned by IANA. The following are the 704 suggested values: 706 +---------------------+--------------------------+-------------+ 707 | Suggested Codepoint | Description | Defined in: | 708 +---------------------+--------------------------+-------------+ 709 | 7 | Protocol-ID | Section 4 | 710 | 516 | BGP Router ID | Section 4.1 | 711 | 517 | BGP Confederation Member | Section 4.1 | 712 | 1101 | Peer-Node-SID | Section 4.3 | 713 | 1102 | Peer-Adj-SID | Section 4.3 | 714 | 1103 | Peer-Set-SID | Section 4.3 | 715 +---------------------+--------------------------+-------------+ 717 Table 1: Summary Table of BGP-LS EPE Codepoints 719 8. Manageability Considerations 721 TBD 723 9. Security Considerations 725 [I-D.ietf-idr-ls-distribution] defines BGP-LS NLRIs to which the 726 extensions defined in this document apply. 728 The Security Section of [I-D.ietf-idr-ls-distribution] also applies 729 to: 731 o New Node Descriptors Sub-TLVs: BGP-Router-ID and BGP- 732 Confederation-Member; 734 o New BGP-LS Attributes TLVs: Peer-Node-SID, Peer-Adj-SID and Peer- 735 Set-SID. 737 10. Contributors 739 Acee Lindem gave a substantial contribution to this document. 741 11. Acknowledgements 743 The authors would like to thank Jakob Heitz, Howard Yang, Hannes 744 Gredler, Peter Psenak, Ketan Jivan Talaulikar, and Arjun Sreekantiah 745 for their feedback and comments. 747 12. References 749 12.1. Normative References 751 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 752 Requirement Levels", BCP 14, RFC 2119, 753 DOI 10.17487/RFC2119, March 1997, 754 . 756 [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A 757 Border Gateway Protocol 4 (BGP-4)", RFC 4271, 758 DOI 10.17487/RFC4271, January 2006, 759 . 761 [RFC5065] Traina, P., McPherson, D., and J. Scudder, "Autonomous 762 System Confederations for BGP", RFC 5065, 763 DOI 10.17487/RFC5065, August 2007, 764 . 766 [RFC5307] Kompella, K., Ed. and Y. Rekhter, Ed., "IS-IS Extensions 767 in Support of Generalized Multi-Protocol Label Switching 768 (GMPLS)", RFC 5307, DOI 10.17487/RFC5307, October 2008, 769 . 771 [RFC6286] Chen, E. and J. Yuan, "Autonomous-System-Wide Unique BGP 772 Identifier for BGP-4", RFC 6286, DOI 10.17487/RFC6286, 773 June 2011, . 775 12.2. Informative References 777 [I-D.filsfils-spring-segment-routing-central-epe] 778 Filsfils, C., Previdi, S., Patel, K., Shaw, S., Ginsburg, 779 D., and D. Afanasiev, "Segment Routing Centralized Egress 780 Peer Engineering", draft-filsfils-spring-segment-routing- 781 central-epe-05 (work in progress), August 2015. 783 [I-D.ietf-idr-ls-distribution] 784 Gredler, H., Medved, J., Previdi, S., Farrel, A., and S. 785 Ray, "North-Bound Distribution of Link-State and TE 786 Information using BGP", draft-ietf-idr-ls-distribution-13 787 (work in progress), October 2015. 789 [I-D.ietf-spring-segment-routing] 790 Filsfils, C., Previdi, S., Decraene, B., Litkowski, S., 791 and r. rjs@rob.sh, "Segment Routing Architecture", draft- 792 ietf-spring-segment-routing-06 (work in progress), October 793 2015. 795 Authors' Addresses 797 Stefano Previdi (editor) 798 Cisco Systems, Inc. 799 Via Del Serafico, 200 800 Rome 00142 801 Italy 803 Email: sprevidi@cisco.com 805 Clarence Filsfils 806 Cisco Systems, Inc. 807 Brussels 808 BE 810 Email: cfilsfil@cisco.com 812 Saikat Ray 813 Individual Contributor 815 Email: raysaikat@gmail.com 817 Keyur Patel 818 Cisco Systems, Inc. 819 170, West Tasman Drive 820 San Jose, CA 95134 821 US 823 Email: keyupate@cisco.com 825 Jie Dong 826 Huawei Technologies 827 Huawei Campus, No. 156 Beiqing Rd. 828 Beijing 100095 829 China 831 Email: jie.dong@huawei.com 832 Mach (Guoyi) Chen 833 Huawei Technologies 834 Huawei Campus, No. 156 Beiqing Rd. 835 Beijing 100095 836 China 838 Email: mach.chen@huawei.com