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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Looks like a reference, but probably isn't: '0' on line 635 -- Looks like a reference, but probably isn't: '1' on line 616 -- Obsolete informational reference (is this intentional?): RFC 2460 (Obsoleted by RFC 8200) Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 4 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 6man R. Bonica 3 Internet-Draft Juniper Networks 4 Intended status: Standards Track Y. Kamite 5 Expires: October 5, 2020 NTT Communications Corporation 6 T. Niwa 7 KDDI 8 A. Alston 9 Liquid Telecom 10 L. Jalil 11 Verizon 12 April 3, 2020 14 The IPv6 Compressed Routing Header (CRH) 15 draft-bonica-6man-comp-rtg-hdr-14 17 Abstract 19 This document defines two new Routing header types. Collectively, 20 they are called the Compressed Routing Headers (CRH). Individually, 21 they are called CRH-16 and CRH-32. 23 Status of This Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at https://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on October 5, 2020. 40 Copyright Notice 42 Copyright (c) 2020 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (https://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 58 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 59 3. The Compressed Routing Headers (CRH) . . . . . . . . . . . . 3 60 4. The CRH Forwarding Information Base (CRH-FIB) . . . . . . . 5 61 5. Processing Rules . . . . . . . . . . . . . . . . . . . . . . 6 62 5.1. Computing Minimum CRH Length . . . . . . . . . . . . . . 7 63 6. Mutability . . . . . . . . . . . . . . . . . . . . . . . . . 8 64 7. Applications And SIDs . . . . . . . . . . . . . . . . . . . . 8 65 8. Management Considerations . . . . . . . . . . . . . . . . . . 9 66 9. ICMPv6 Considerations . . . . . . . . . . . . . . . . . . . . 9 67 10. Security Considerations . . . . . . . . . . . . . . . . . . . 9 68 11. Implementation and Deployment Status . . . . . . . . . . . . 9 69 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 70 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 71 14. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 72 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 73 15.1. Normative References . . . . . . . . . . . . . . . . . . 11 74 15.2. Informative References . . . . . . . . . . . . . . . . . 12 75 Appendix A. CRH Processing Examples . . . . . . . . . . . . . . 12 76 Appendix B. CRH Processing Examples . . . . . . . . . . . . . . 13 77 B.1. The SID List Contains One Entry For Each Segment In The 78 Path . . . . . . . . . . . . . . . . . . . . . . . . . . 14 79 B.2. The SID List Omits The First Entry In The Path . . . . . 15 80 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 82 1. Introduction 84 IPv6 [RFC8200] source nodes use Routing headers to specify the path 85 that a packet takes to its destination. The IETF has defined several 86 Routing header types [IANA-RH]. RH0 [RFC2460] was the first to be 87 defined and was deprecated [RFC5095] because of security 88 vulnerabilities. 90 This document defines two new Routing header types. Collectively, 91 they are called the Compressed Routing Headers (CRH). Individually, 92 they are called CRH-16 and CRH-32. 94 The CRH, like RH0, allows IPv6 source nodes to specify the path that 95 a packet takes to its destination. The CRH differs from RH0 because: 97 o It can be encoded in fewer bytes than RH0. 99 o It addresses the security vulnerabilities that affected RH0. 101 The following are reasons for encoding the CRH in as few bytes as 102 possible: 104 o Many ASIC-based forwarders copy all headers from buffer memory to 105 on-chip memory. As header sizes increase, so does the cost of 106 this copy. 108 o Because Path MTU Discovery (PMTUD) [RFC8201] is not entirely 109 reliable, many IPv6 hosts refrain from sending packets larger than 110 the IPv6 minimum link MTU (i.e., 1280 bytes). When packets are 111 small, the overhead imposed by large Routing Headers is excessive. 113 Section 10 of this document addresses security considerations. 114 Appendix A of this document demonstrates how the CRH can be encoded 115 in fewer bytes than RH0. 117 2. Requirements Language 119 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 120 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 121 "OPTIONAL" in this document are to be interpreted as described in BCP 122 14 [RFC2119] [RFC8174] when, and only when, they appear in all 123 capitals, as shown here. 125 3. The Compressed Routing Headers (CRH) 127 Both CRH versions (i.e., CRH-16 and CRH-32) contain the following 128 fields: 130 o Next Header - Defined in [RFC8200]. 132 o Hdr Ext Len - Defined in [RFC8200]. 134 o Routing Type - Defined in [RFC8200]. Value TBD by IANA. (For 135 CRH-16, the suggested value is 5. For CRH-32, the suggested value 136 is 6.) 138 o Segments Left - Defined in [RFC8200]. 140 o Type-specific Data - Described in [RFC8200]. 142 In the CRH, the Type-specific data field contains a list of Segment 143 Identifiers (SIDs). Each SID represents both of the following: 145 o A segment of the path that the packet takes to its destination. 147 o An entry in the CRH Forwarding Information Base (CRH-FIB) 148 (Section 4). 150 SIDs are listed in reverse order. So, the first SID in the list 151 represents the final segment in the path. Because segments are 152 listed in reverse order, the Segments Left field can be used as an 153 index into the SID list. In this document, the "current SID" is the 154 SID list entry referenced by the Segments Left field. 156 The first segment in the path can be omitted from the list. See 157 (Appendix B) for examples. 159 In the CRH-16 (Figure 1), each SID is encoded in 16-bits. In the 160 CRH-32 (Figure 2), each SID is encoded in 32-bits. 162 In all cases, the CRH MUST end on a 64-bit boundary. So, the Type- 163 specific data field MUST be padded with zeros if the CRH would 164 otherwise not end on a 64-bit boundary. 166 0 1 2 3 167 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 1 168 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 169 | Next Header | Hdr Ext Len | Routing Type | Segments Left | 170 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 171 | SID[0] | SID[1] | 172 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-| 173 | ......... 174 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 176 Figure 1: CRH-16 178 0 1 2 3 179 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 1 180 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 181 | Next Header | Hdr Ext Len | Routing Type | Segments Left | 182 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 + SID[0] + 184 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 + SID[1] + 186 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 // // 188 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 + SID[n] + 190 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 192 Figure 2: CRH-32 194 4. The CRH Forwarding Information Base (CRH-FIB) 196 Each SID identifies a CRH-FIB entry. 198 Each CRH-FIB entry contains: 200 o A IPv6 address. 202 o A forwarding method. 204 o Method-specific parameters (optional). 206 The IPv6 address represents an interface on the next segment 207 endpoint. It MUST NOT be a link-local address. While the IPv6 208 address represents an interface on the next segment endpoint, it does 209 not necessarily represent the interface through which the packet will 210 arrive at the next segment endpoint. 212 The forwarding method specifies how the processing node will forward 213 the packet to the next segment endpoint. The following are examples: 215 o Forward the packet to the next-hop along the least-cost path to 216 the next segment endpoint. 218 o Forward the packet through a specified interface to the next 219 segment endpoint. 221 Some forwarding methods require method-specific parameters. For 222 example, a forwarding method might require a parameter that 223 identifies the interface through which the packet should be 224 forwarded. 226 The CRH-FIB can be populated: 228 o By an operator, using a Command Line Interface (CLI). 230 o By a controller, using the Path Computation Element (PCE) 231 Communication Protocol (PCEP) [RFC5440] or the Network 232 Configuration Protocol (NETCONF) [RFC6241]. 234 o By a distributed routing protocol [ISO10589-Second-Edition], 235 [RFC5340], [RFC4271]. 237 5. Processing Rules 239 The following rules apply to packets that contain a CRH: 241 o If the IPv6 Source Address is a link-local address, discard the 242 packet. 244 o If the IPv6 Source Address is a multicast address, discard the 245 packet. 247 o If the IPv6 Destination Address is a link-local address, discard 248 the packet. 250 o If the IPv6 Hop Limit is less than or equal to 1, discard the 251 packet and send an ICMPv6 Time Exceeded message to the Source 252 Address. 254 The following rules describe CRH processing: 256 o If Segments Left equals 0, skip over the CRH and process the next 257 header in the packet. 259 o If Hdr Ext Len indicates that the CRH is larger than the 260 implementation can process, discard the packet and send an ICMPv6 261 Parameter Problem, Code 0, message to the Source Address, pointing 262 to the Hdr Ext Len field. 264 o Compute L, the minimum CRH length (See (Section 5.1)). 266 o If L is greater than Hdr Ext Len, discard the packet and send an 267 ICMPv6 Parameter Problem, Code 0, message to the Source Address, 268 pointing to the Segments Left field. 270 o Decrement Segments Left. 272 o Search for the current SID in the CRH-FIB. In this document, the 273 "current SID" is the SID list entry referenced by the Segments 274 Left field. 276 o If the search does not return a CRH-FIB entry, discard the packet 277 and send an ICMPv6 Parameter Problem, Code 0, message to the 278 Source Address, pointing to the current SID. 280 o If the CRH-FIB entry contains a link-local address, discard the 281 packet and send an ICMPv6 Parameter Problem, Code 0, message to 282 the Source Address, pointing to the current SID. 284 o If Segments Left is greater than 0 and the CRH-FIB entry contains 285 a multicast address, discard the packet and send an ICMPv6 286 Parameter Problem, Code 0, message to the Source Address, pointing 287 to the current SID. 289 o Copy the IPv6 address from the CRH-FIB entry to the Destination 290 Address field in the IPv6 header. 292 o Decrement the IPv6 Hop Limit. 294 o Resubmit the packet to the IPv6 module for transmission to the new 295 destination, ensuring that it executes the forwarding method 296 specified by the CRH-FIB entry. 298 5.1. Computing Minimum CRH Length 300 The algorithm described in this section accepts the following CRH 301 fields as its input parameters: 303 o Routing Type (i.e., CRH-16 or CRH-32). 305 o Segments Left. 307 It yields L, the minimum CRH length. The minimum CRH length is 308 measured in 8-octet units, not including the first 8 octets. 310 312 switch(Routing Type) { 313 case CRH-16: 314 if (Segments Left <= 2) 315 return(0) 316 sidsBeyondFirstWord = Segments Left - 2; 317 sidPerWord = 4; 318 case CRH-32: 319 if (Segments Left <= 1) 320 return(0) 321 sidsBeyondFirstWord = Segments Left - 1; 322 sidsPerWord = 2; 323 case default: 324 return(0xFF); 325 } 327 words = sidsBeyondFirstWord div sidsPerWord; 328 if (sidsBeyondFirstWord mod sidsPerWord) 329 words++; 331 return(words) 333 335 6. Mutability 337 In the CRH, the Segments Left field is mutable. All remaining fields 338 are immutable. 340 7. Applications And SIDs 342 A CRH contains one or more SIDs. Each SID is processed by exactly 343 one node. 345 Therefore, a SID is not required to have domain-wide significance. 346 Applications can: 348 o Allocate SIDs so that they have domain-wide significance. 350 o Allocate SIDs so that they have node-local significance. 352 8. Management Considerations 354 PING and TRACEROUTE [RFC2151] both operate correctly in the presence 355 of the CRH. 357 9. ICMPv6 Considerations 359 Implementations MUST comply with the ICMPv6 processing rules 360 specified in Section 2.4 of [RFC4443]. For example: 362 o An implementation MUST NOT originate an ICMPv6 error message in 363 response to another ICMPv6 error message. 365 o An implementation MUST rate limit the ICMPv6 messages that it 366 originates. 368 10. Security Considerations 370 Networks that process the CRH MUST mitigate the security 371 vulnerabilities described in [RFC5095]. Their border routers SHOULD 372 discard packets that satisfy the following criteria: 374 o The packet contains a CRH 376 o The Segments Left field in the CRH has a value greater than 0 378 o The Destination Address field in the IPv6 header represents an 379 interface that resides inside of the network. 381 Many border routers cannot filter packets based upon the Segments 382 Left value. These border routers MAY discard packets that satisfy 383 the following criteria: 385 o The packet contains a CRH 387 o The Destination Address field in the IPv6 header represents an 388 interface that resides inside of the network. 390 11. Implementation and Deployment Status 392 Juniper Networks has produced experimental implementations of the CRH 393 on: 395 o A LINUX-based software platform 397 o The MX-series (ASIC-based) router 398 Liquid Telecom has deployed the CRH, on a limited basis, in their 399 network. Other experimental deployments are in progress. 401 12. IANA Considerations 403 SID values 0-15 are reserved for future use. They may be assigned by 404 IANA, based on IETF Consensus. IANA is requested to establish a 405 "Registry of SRm6 Reserved SIDs". Values 0-15 are reserved for 406 future use. 408 IANA is requested to make the following entries in the Internet 409 Protocol Version 6 (IPv6) Parameters "Routing Type" registry 410 [IANA-RH]: 412 Suggested 413 Value Description Reference 414 --------------------------------------------------------------------- 415 5 Compressed Routing Header (16-bit) (CRH-16) This document 416 6 Compressed Routing Header (32-bit) (CRH-32) This document 418 13. Acknowledgements 420 Thanks to Dr. Vanessa Ameen, Fernando Gont, Naveen Kottapalli, Joel 421 Halpern, Tony Li, Gerald Schmidt, Nancy Shaw, and Chandra Venkatraman 422 for their contributions to this document. 424 14. Contributors 426 Daniam Henriques 428 Liquid Telecom 430 Johannesburg, South Africa 432 Email: daniam.henriques@liquidtelecom.com 434 Gang Chen 436 Baidu 438 No.10 Xibeiwang East Road Haidian District 440 Beijing 100193 P.R. China 442 Email: phdgang@gmail.com 443 Yifeng Zhou 445 ByteDance 447 Building 1, AVIC Plaza, 43 N 3rd Ring W Rd Haidian District 449 Beijing 100000 P.R. China 451 Email: yifeng.zhou@bytedance.com 453 15. References 455 15.1. Normative References 457 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 458 Requirement Levels", BCP 14, RFC 2119, 459 DOI 10.17487/RFC2119, March 1997, 460 . 462 [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet 463 Control Message Protocol (ICMPv6) for the Internet 464 Protocol Version 6 (IPv6) Specification", STD 89, 465 RFC 4443, DOI 10.17487/RFC4443, March 2006, 466 . 468 [RFC5095] Abley, J., Savola, P., and G. Neville-Neil, "Deprecation 469 of Type 0 Routing Headers in IPv6", RFC 5095, 470 DOI 10.17487/RFC5095, December 2007, 471 . 473 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 474 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 475 May 2017, . 477 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 478 (IPv6) Specification", STD 86, RFC 8200, 479 DOI 10.17487/RFC8200, July 2017, 480 . 482 [RFC8201] McCann, J., Deering, S., Mogul, J., and R. Hinden, Ed., 483 "Path MTU Discovery for IP version 6", STD 87, RFC 8201, 484 DOI 10.17487/RFC8201, July 2017, 485 . 487 15.2. Informative References 489 [IANA-RH] IANA, "Routing Headers", 490 . 493 [ISO10589-Second-Edition] 494 International Organization for Standardization, 495 ""Intermediate system to Intermediate system intra-domain 496 routeing information exchange protocol for use in 497 conjunction with the protocol for providing the 498 connectionless-mode Network Service (ISO 8473)", ISO/IEC 499 10589:2002, Second Edition,", November 2001. 501 [RFC2151] Kessler, G. and S. Shepard, "A Primer On Internet and TCP/ 502 IP Tools and Utilities", FYI 30, RFC 2151, 503 DOI 10.17487/RFC2151, June 1997, 504 . 506 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 507 (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460, 508 December 1998, . 510 [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A 511 Border Gateway Protocol 4 (BGP-4)", RFC 4271, 512 DOI 10.17487/RFC4271, January 2006, 513 . 515 [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF 516 for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008, 517 . 519 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 520 Element (PCE) Communication Protocol (PCEP)", RFC 5440, 521 DOI 10.17487/RFC5440, March 2009, 522 . 524 [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., 525 and A. Bierman, Ed., "Network Configuration Protocol 526 (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, 527 . 529 Appendix A. CRH Processing Examples 531 The CRH-16 and CRH-32 encode information more efficiently than RH0. 533 +------+-----+--------+--------+ 534 | SIDs | RH0 | CRH-16 | CRH-32 | 535 +------+-----+--------+--------+ 536 | 1 | 24 | 8 | 8 | 537 | 2 | 40 | 8 | 16 | 538 | 3 | 56 | 16 | 16 | 539 | 4 | 72 | 16 | 24 | 540 | 5 | 88 | 16 | 24 | 541 | 6 | 104 | 16 | 32 | 542 | 7 | 120 | 24 | 32 | 543 | 8 | 136 | 24 | 40 | 544 | 9 | 152 | 24 | 40 | 545 | 10 | 168 | 24 | 48 | 546 | 11 | 184 | 32 | 48 | 547 | 12 | 200 | 32 | 52 | 548 | 13 | 216 | 32 | 52 | 549 | 14 | 232 | 32 | 56 | 550 | 15 | 248 | 40 | 56 | 551 | 16 | 264 | 40 | 60 | 552 | 17 | 280 | 40 | 60 | 553 | 18 | 296 | 40 | 64 | 554 +------+-----+--------+--------+ 556 Table 1: Routing Header Size (in Bytes) As A Function Of Routing 557 Header Type and Number Of SIDs 559 (Table 1) reflects Routing header size as a function of Routing 560 header type and number of SIDs contained by the Routing header. 562 Appendix B. CRH Processing Examples 564 This appendix demonstrates CRH processing in the following scenarios: 566 o The SID list contains one entry for each segment in the path 567 (Appendix B.1). 569 o The SID list omits the first entry in the path (Appendix B.2). 571 ----------- ----------- ----------- 572 |Node: S | |Node: I1 | |Node: I2 | 573 |Loopback: |---------------|Loopback: |---------------|Loopback: | 574 |2001:db8::a| |2001:db8::1| |2001:db8::2| 575 ----------- ----------- ----------- 576 | | 577 | ----------- | 578 | |Node: D | | 579 ---------------------|Loopback: |--------------------- 580 |2001:db8::b| 581 ----------- 583 Figure 3: Reference Topology 585 Figure 3 provides a reference topology that is used in all examples. 587 +-----+--------------+-------------------+ 588 | SID | IPv6 Address | Forwarding Method | 589 +-----+--------------+-------------------+ 590 | 2 | 2001:db8::2 | Least-cost path | 591 | 11 | 2001:db8::b | Least-cost path | 592 +-----+--------------+-------------------+ 594 Table 2: Node SIDs 596 Table 2 describes two entries that appear in each node's CRH-FIB. 598 B.1. The SID List Contains One Entry For Each Segment In The Path 600 In this example, Node S sends a packet to Node D, via I2. In this 601 example, I2 appears in the CRH segment list. 603 +-------------------------------------+-------------------+ 604 | As the packet travels from S to I2: | | 605 +-------------------------------------+-------------------+ 606 | Source Address = 2001:db8::a | Segments Left = 1 | 607 | Destination Address = 2001:db8::2 | SID[0] = 11 | 608 | | SID[1] = 2 | 609 +-------------------------------------+-------------------+ 611 +-------------------------------------+-------------------+ 612 | As the packet travels from I2 to D: | | 613 +-------------------------------------+-------------------+ 614 | Source Address = 2001:db8::a | Segments Left = 0 | 615 | Destination Address = 2001:db8::b | SID[0] = 11 | 616 | | SID[1] = 2 | 617 +-------------------------------------+-------------------+ 619 B.2. The SID List Omits The First Entry In The Path 621 In this example, Node S sends a packet to Node D, via I2. In this 622 example, I2 does not appear in the CRH segment list. 624 +-------------------------------------+-------------------+ 625 | As the packet travels from S to I2: | | 626 +-------------------------------------+-------------------+ 627 | Source Address = 2001:db8::a | Segments Left = 1 | 628 | Destination Address = 2001:db8::2 | SID[0] = 11 | 629 +-------------------------------------+-------------------+ 631 +-------------------------------------+-------------------+ 632 | As the packet travels from I2 to D: | | 633 +-------------------------------------+-------------------+ 634 | Source Address = 2001:db8::a | Segments Left = 0 | 635 | Destination Address = 2001:db8::b | SID[0] = 11 | 636 +-------------------------------------+-------------------+ 638 Authors' Addresses 640 Ron Bonica 641 Juniper Networks 642 2251 Corporate Park Drive 643 Herndon, Virginia 20171 644 USA 646 Email: rbonica@juniper.net 648 Yuji Kamite 649 NTT Communications Corporation 650 3-4-1 Shibaura, Minato-ku 651 Tokyo 108-8118 652 Japan 654 Email: y.kamite@ntt.com 656 Tomonobu Niwa 657 KDDI 658 3-22-7, Yoyogi, Shibuya-ku 659 Tokyo 151-0053 660 Japan 662 Email: to-niwa@kddi.com 663 Andrew Alston 664 Liquid Telecom 665 Nairobi 666 Kenya 668 Email: Andrew.Alston@liquidtelecom.com 670 Luay Jalil 671 Verizon 672 Richardson, Texas 673 USA 675 Email: luay.jalil@one.verizon.com