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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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-11) exists of draft-ietf-l2vpn-evpn-06 Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 8 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Internet Engineering Task Force E. Chen, Ed. 3 Internet-Draft Cisco Systems, Inc. 4 Updates: 1997, 4271, 4360, 4456, 4760, 5701 (if approved)J. Scudder, Ed. 5 Intended status: Standards Track Juniper Networks 6 Expires: November 8, 2014 P. Mohapatra 7 Sproute Networks 8 K. Patel 9 Cisco Systems, Inc. 10 May 7, 2014 12 Revised Error Handling for BGP UPDATE Messages 13 draft-ietf-idr-error-handling-07 15 Abstract 17 According to the base BGP specification, a BGP speaker that receives 18 an UPDATE message containing a malformed attribute is required to 19 reset the session over which the offending attribute was received. 20 This behavior is undesirable as a session reset would impact not only 21 routes with the offending attribute, but also other valid routes 22 exchanged over the session. This document partially revises the 23 error handling for UPDATE messages, and provides guidelines for the 24 authors of documents defining new attributes. Finally, it revises 25 the error handling procedures for a number of existing attributes. 27 This document updates error handling for RFCs 1997, 4271, 4360, 4456, 28 4760, and 5701. 30 Status of This Memo 32 This Internet-Draft is submitted in full conformance with the 33 provisions of BCP 78 and BCP 79. 35 Internet-Drafts are working documents of the Internet Engineering 36 Task Force (IETF). Note that other groups may also distribute 37 working documents as Internet-Drafts. The list of current Internet- 38 Drafts is at http://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 This Internet-Draft will expire on November 8, 2014. 47 Copyright Notice 49 Copyright (c) 2014 IETF Trust and the persons identified as the 50 document authors. All rights reserved. 52 This document is subject to BCP 78 and the IETF Trust's Legal 53 Provisions Relating to IETF Documents 54 (http://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 This document may contain material from IETF Documents or IETF 63 Contributions published or made publicly available before November 64 10, 2008. The person(s) controlling the copyright in some of this 65 material may not have granted the IETF Trust the right to allow 66 modifications of such material outside the IETF Standards Process. 67 Without obtaining an adequate license from the person(s) controlling 68 the copyright in such materials, this document may not be modified 69 outside the IETF Standards Process, and derivative works of it may 70 not be created outside the IETF Standards Process, except to format 71 it for publication as an RFC or to translate it into languages other 72 than English. 74 Table of Contents 76 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 77 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 78 2. Revision to Base Specification . . . . . . . . . . . . . . . 4 79 3. Parsing of NLRI Fields . . . . . . . . . . . . . . . . . . . 6 80 3.1. Inconsistency of Attribute Length Fields . . . . . . . . 6 81 3.2. Syntactic Correctness of NLRI Fields . . . . . . . . . . 7 82 3.3. Typed NLRI . . . . . . . . . . . . . . . . . . . . . . . 7 83 4. Operational Considerations . . . . . . . . . . . . . . . . . 8 84 5. Error Handling Procedures for Existing Attributes . . . . . . 9 85 5.1. ORIGIN . . . . . . . . . . . . . . . . . . . . . . . . . 9 86 5.2. AS_PATH . . . . . . . . . . . . . . . . . . . . . . . . . 9 87 5.3. NEXT_HOP . . . . . . . . . . . . . . . . . . . . . . . . 9 88 5.4. MULTI_EXIT_DESC . . . . . . . . . . . . . . . . . . . . . 9 89 5.5. LOCAL_PREF . . . . . . . . . . . . . . . . . . . . . . . 9 90 5.6. ATOMIC_AGGREGATE . . . . . . . . . . . . . . . . . . . . 10 91 5.7. AGGREGATOR . . . . . . . . . . . . . . . . . . . . . . . 10 92 5.8. Community . . . . . . . . . . . . . . . . . . . . . . . . 10 93 5.9. Extended Community . . . . . . . . . . . . . . . . . . . 10 94 5.10. IPv6 Address Specific BGP Extended Community Attribute . 11 95 5.11. ORIGINATOR_ID . . . . . . . . . . . . . . . . . . . . . . 11 96 5.12. CLUSTER_LIST . . . . . . . . . . . . . . . . . . . . . . 11 97 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 98 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 99 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 100 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 101 9.1. Normative References . . . . . . . . . . . . . . . . . . 12 102 9.2. Informative References . . . . . . . . . . . . . . . . . 13 103 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 105 1. Introduction 107 According to the base BGP specification [RFC4271], a BGP speaker that 108 receives an UPDATE message containing a malformed attribute is 109 required to reset the session over which the offending attribute was 110 received. This behavior is undesirable as a session reset would 111 impact not only routes with the offending attribute, but also other 112 valid routes exchanged over the session. In the case of optional 113 transitive attributes, the behavior is especially troublesome and may 114 present a potential security vulnerability. The reason is that such 115 attributes may have been propagated without being checked by 116 intermediate routers that do not recognize the attributes -- in 117 effect the attribute may have been tunneled, and when they do reach a 118 router that recognizes and checks them, the session that is reset may 119 not be associated with the router that is at fault. 121 The goal for revising the error handling for UPDATE messages is to 122 minimize the impact on routing by a malformed UPDATE message, while 123 maintaining protocol correctness to the extent possible. This can be 124 achieved largely by maintaining the established session and keeping 125 the valid routes exchanged, but removing the routes carried in the 126 malformed UPDATE from the routing system. 128 This document partially revises the error handling for UPDATE 129 messages, and provides guidelines for the authors of documents 130 defining new attributes. Finally, it revises the error handling 131 procedures for a number of existing attributes. Specifically, the 132 error handling procedures of, [RFC1997], [RFC4271], [RFC4360], 133 [RFC4456], [RFC4760] and [RFC5701] are revised. 135 1.1. Requirements Language 137 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 138 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 139 document are to be interpreted as described in RFC 2119 [RFC2119]. 141 2. Revision to Base Specification 143 The first paragraph of Section 6.3 of [RFC4271] is revised as 144 follows: 146 Old Text: 148 All errors detected while processing the UPDATE message MUST be 149 indicated by sending the NOTIFICATION message with the Error Code 150 UPDATE Message Error. The error subcode elaborates on the 151 specific nature of the error. 153 New text: 155 An error detected while processing the UPDATE message for which a 156 session reset is specified MUST be indicated by sending the 157 NOTIFICATION message with the Error Code UPDATE Message Error. 158 The error subcode elaborates on the specific nature of the error. 160 The error handling of the following case described in Section 6.3 of 161 [RFC4271] remains unchanged: 163 If the Withdrawn Routes Length or Total Attribute Length is too 164 large (i.e., if Withdrawn Routes Length + Total Attribute Length + 165 23 exceeds the message Length), then the Error Subcode MUST be set 166 to Malformed Attribute List. 168 The error handling of the following case described in Section 6.3 of 169 [RFC4271] is revised 171 If any recognized attribute has Attribute Flags that conflict with 172 the Attribute Type Code, then the Error Subcode MUST be set to 173 Attribute Flags Error. The Data field MUST contain the erroneous 174 attribute (type, length, and value). 176 as follows: 178 If any recognized attribute has Attribute Flags that conflict with 179 the Attribute Type Code, then the attribute MUST be treated as 180 malformed and the treat-as-withdraw approach (see below) used, 181 unless the specification for the attribute mandates different 182 handling for incorrect Attribute Flags. 184 The error handling of all other cases involving path attributes as 185 described in Section 6.3 of [RFC4271] that specify a session reset is 186 revised as follows. 188 When a path attribute (other than the MP_REACH_NLRI attribute 189 [RFC4760] or the MP_UNREACH_NLRI attribute [RFC4760]) in an UPDATE 190 message is determined to be malformed, the UPDATE message containing 191 that attribute MUST be treated as though all contained routes had 192 been withdrawn just as if they had been listed in the WITHDRAWN 193 ROUTES field (or in the MP_UNREACH_NLRI attribute if appropriate) of 194 the UPDATE message, thus causing them to be removed from the Adj-RIB- 195 In according to the procedures of [RFC4271]. In the case of an 196 attribute which has no effect on route selection or installation, the 197 malformed attribute MAY instead be discarded and the UPDATE message 198 continue to be processed. For the sake of brevity, the former 199 approach is termed "treat-as-withdraw", and the latter as "attribute 200 discard". 202 If any of the well-known mandatory attributes are not present in an 203 UPDATE message, then the approach of "treat-as-withdraw" MUST be used 204 for the error handling. 206 The approach of "treat-as-withdraw" MUST be used for the error 207 handling of the cases described in Section 6.3 of [RFC4271] that 208 specify a session reset and involve any of the following attributes: 209 ORIGIN, AS_PATH, NEXT_HOP, MULTI_EXIT_DISC, and LOCAL_PREF. 211 The approach of "attribute discard" MUST be used for the error 212 handling of the cases described in Section 6.3 of [RFC4271] that 213 specify a session reset and involve any of the following attributes: 214 ATOMIC_AGGREGATE and AGGREGATOR. 216 If the MP_REACH_NLRI attribute or the MP_UNREACH_NLRI attribute 217 appears more than once in the UPDATE message, then a NOTIFICATION 218 message MUST be sent with the Error Subcode "Malformed Attribute 219 List". If any other attribute appears more than once in an UPDATE 220 message, then all the occurrences of the attribute other than the 221 first one SHALL be discarded and the UPDATE message continue to be 222 processed. 224 When multiple attribute errors exist in an UPDATE message, if the 225 same approach (either "session reset", or "treat-as-withdraw" or 226 "attribute discard") is specified for the handling of these malformed 227 attributes, then the specified approach MUST be used. Otherwise the 228 approach with the strongest action MUST be used following the order 229 of "session reset", "treat-as-withdraw" and "attribute discard" from 230 the strongest to the weakest. 232 A document which specifies a new attribute MUST provide specifics 233 regarding what constitutes an error for that attribute and how that 234 error is to be handled. 236 Finally, we observe that in order to use the approach of "treat-as- 237 withdraw", the entire NLRI field and/or the MP_REACH_NLRI and 238 MP_UNREACH_NLRI attributes need to be successfully parsed. If this 239 is not possible, the procedures of [RFC4271] continue to apply, 240 meaning that the session MUST be reset and a NOTIFICATION sent. 241 Alternatively the error handling procedures specified in [RFC4760] 242 for disabling a particular AFI/SAFI MAY be followed. One notable 243 case where it would be not possible to successfully parse the NLRI is 244 if the NLRI field is found to be "syntactically incorrect" (see 245 Section 3.2). It can be seen that therefore, this part of [RFC4271] 246 Section 6.3 necessarily continues to apply: 248 The NLRI field in the UPDATE message is checked for syntactic 249 validity. If the field is syntactically incorrect, then the Error 250 Subcode MUST be set to Invalid Network Field. 252 Furthermore, this document extends RFC 4271 by mandating that the 253 Withdrawn Routes field SHALL be checked for syntactic correctness in 254 the same manner as the NLRI field. 256 3. Parsing of NLRI Fields 258 To facilitate the determination of the NLRI field in an UPDATE with a 259 malformed attribute, the MP_REACH_NLRI or MP_UNREACH_NLRI attribute 260 (if present) SHALL be encoded as the very first path attribute in an 261 UPDATE. An implementation, however, MUST still be prepared to 262 receive these fields in any position. 264 If the encoding of [RFC4271] is used, the NLRI field for the IPv4 265 unicast address family is carried immediately following all the 266 attributes in an UPDATE. When such an UPDATE is received, we observe 267 that the NLRI field can be determined using the "Message Length", 268 "Withdrawn Route Length" and "Total Attribute Length" (when they are 269 consistent) carried in the message instead of relying on the length 270 of individual attributes in the message. 272 3.1. Inconsistency of Attribute Length Fields 274 There are two error cases in which the Total Attribute Length value 275 can be in conflict with the enclosed path attributes, which 276 themselves carry length values. In the "overrun" case, as the 277 enclosed path attributes are parsed, the length of the last 278 encountered path attribute would cause the Total Attribute Length to 279 be exceeded. In the "underrun" case, as the enclosed path attributes 280 are parsed, after the last successfully-parsed attribute, fewer than 281 three bytes remain, or fewer than four bytes, if the Attribute Flags 282 field has the Extended Length bit set -- that is, there remains 283 unconsumed data in the path attributes but yet insufficient data to 284 encode a single minimum-sized path attribute. In either of these 285 cases an error condition exists and the treat-as-withdraw approach 286 MUST be used (unless some other, more severe error is encountered 287 dictating a stronger approach), and the Total Attribute Length MUST 288 be relied upon to enable the beginning of the NLRI field to be 289 located. 291 3.2. Syntactic Correctness of NLRI Fields 293 The NLRI field or Withdrawn Routes field SHALL be considered 294 "syntactically incorrect" if either of the following are true: 296 o The length of any of the included NLRI is greater than 32, 298 o When parsing NLRI contained in the field, the length of the last 299 NLRI found exceeds the amount of unconsumed data remaining in the 300 field. 302 Similarly, the MP_REACH or MP_UNREACH attribute of an update SHALL be 303 considered to be incorrect if any of the following are true: 305 o The length of any of the included NLRI is inconsistent with the 306 given AFI/SAFI (for example, if an IPv4 NLRI has a length greater 307 than 32 or an IPv6 NLRI has a length greater than 128), 309 o When parsing NLRI contained in the attribute, the length of the 310 last NLRI found exceeds the amount of unconsumed data remaining in 311 the attribute. 313 o The attribute flags of the attribute are inconsistent with those 314 specified in [RFC4760]. 316 o The length of the MP_UNREACH attribute is less than 3, or the 317 length of the MP_REACH attribute is less than 5. 319 3.3. Typed NLRI 321 Certain address families, for example MVPN [RFC7117] and EVPN 322 [I-D.ietf-l2vpn-evpn] have NLRI that are typed. Since supported type 323 values with the address family are not expressed in the MP-BGP 324 capability [RFC4760], it is possible for a BGP speaker to advertise 325 support for the given address family and sub-address family while 326 still not supporting a particular type of NLRI within that AFI/SAFI. 328 A BGP speaker advertising support for such a typed address family 329 MUST handle routes with unrecognized NLRI types within that address 330 family by discarding them, unless the relevant specification for that 331 address family specifies otherwise. 333 4. Operational Considerations 335 Although the "treat-as-withdraw" error-handling behavior defined in 336 Section 2 makes every effort to preserve BGP's correctness, we note 337 that if an UPDATE received on an IBGP session is subjected to this 338 treatment, inconsistent routing within the affected Autonomous System 339 may result. The consequences of inconsistent routing can include 340 long-lived forwarding loops and black holes. While lamentable, this 341 issue is expected to be rare in practice, and more importantly is 342 seen as less problematic than the session-reset behavior it replaces. 344 When a malformed attribute is indeed detected over an IBGP session, 345 we RECOMMEND that routes with the malformed attribute be identified 346 and traced back to the ingress router in the network where the routes 347 were sourced or received externally, and then a filter be applied on 348 the ingress router to prevent the routes from being sourced or 349 received. This will help maintain routing consistency in the 350 network. 352 Even if inconsistent routing does not arise, the "treat-as-withdraw" 353 behavior can cause either complete unreachability or sub-optimal 354 routing for the destinations whose routes are carried in the affected 355 UPDATE message. 357 Note that "treat-as-withdraw" is different from discarding an UPDATE 358 message. The latter violates the basic BGP principle of incremental 359 update, and could cause invalid routes to be kept. 361 For any malformed attribute which is handled by the "attribute 362 discard" instead of the "treat-as-withdraw" approach, it is critical 363 to consider the potential impact of doing so. In particular, if the 364 attribute in question has or may have an effect on route selection or 365 installation, the presumption is that discarding it is unsafe, unless 366 careful analysis proves otherwise. The analysis should take into 367 account the tradeoff between preserving connectivity and potential 368 side effects. 370 Because of these potential issues, a BGP speaker MUST provide 371 debugging facilities to permit issues caused by a malformed attribute 372 to be diagnosed. At a minimum, such facilities MUST include logging 373 an error listing the NLRI involved, and containing the entire 374 malformed UPDATE message when such an attribute is detected. The 375 malformed UPDATE message SHOULD be analyzed, and the root cause 376 SHOULD be investigated. 378 5. Error Handling Procedures for Existing Attributes 380 5.1. ORIGIN 382 The attribute is considered malformed if its length is not 1, or it 383 has an undefined value [RFC4271]. 385 An UPDATE message with a malformed ORIGIN attribute SHALL be handled 386 using the approach of "treat-as-withdraw". 388 5.2. AS_PATH 390 The error conditions for the attribute have been defined in 391 [RFC4271]. 393 An UPDATE message with a malformed AS_PATH attribute SHALL be handled 394 using the approach of "treat-as-withdraw". 396 5.3. NEXT_HOP 398 The error conditions for the NEXT_HOP attribute have been defined in 399 [RFC4271]. 401 An UPDATE message with a malformed NEXT_HOP attribute SHALL be 402 handled using the approach of "treat-as-withdraw". 404 5.4. MULTI_EXIT_DESC 406 The attribute is considered malformed if its length is not 4 407 [RFC4271]. 409 An UPDATE message with a malformed MULTI_EXIT_DESC attribute SHALL be 410 handled using the approach of "treat-as-withdraw". 412 5.5. LOCAL_PREF 414 The attribute is considered malformed if its length is not 4 415 [RFC4271]. 417 An UPDATE message with a malformed LOCAL_PREF attribute SHALL be 418 handled as follows: 420 o using the approach of "attribute discard" if the UPDATE message is 421 received from an external neighbor, or 423 o using the approach of "treat-as-withdraw" if the UPDATE message is 424 received from an internal neighbor. 426 In addition, if the attribute is present in an UPDATE message from an 427 external neighbor, the approach of "attribute discard" SHALL be used 428 to handle the unexpected attribute in the message. 430 5.6. ATOMIC_AGGREGATE 432 The attribute SHALL be considered malformed if its length is not 0 433 [RFC4271]. 435 An UPDATE message with a malformed ATOMIC_AGGREGATE attribute SHALL 436 be handled using the approach of "attribute discard". 438 5.7. AGGREGATOR 440 The error conditions specified in [RFC4271] for the attribute are 441 revised as follows: 443 The AGGREGATOR attribute SHALL be considered malformed if any of the 444 following applies: 446 o Its length is not 6 (when the "4-octet AS number capability" is 447 not advertised to, or not received from the peer [RFC6793]). 449 o Its length is not 8 (when the "4-octet AS number capability" is 450 both advertised to, and received from the peer). 452 An UPDATE message with a malformed AGGREGATOR attribute SHALL be 453 handled using the approach of "attribute discard". 455 5.8. Community 457 The error handling of [RFC1997] is revised as follows: 459 The Community attribute SHALL be considered malformed if its length 460 is nonzero and is not a multiple of 4. 462 An UPDATE message with a malformed Community attribute SHALL be 463 handled using the approach of "treat-as-withdraw". 465 5.9. Extended Community 467 The error handling of [RFC4360] is revised as follows: 469 The Extended Community attribute SHALL be considered malformed if its 470 length is nonzero and is not a multiple of 8. 472 An UPDATE message with a malformed Extended Community attribute SHALL 473 be handled using the approach of "treat-as-withdraw". 475 Note that a BGP speaker MUST NOT treat an unrecognized Extended 476 Community Type or Sub-Type as an error. 478 5.10. IPv6 Address Specific BGP Extended Community Attribute 480 The error handling of [RFC5701] is revised as follows: 482 The IPv6 Address Specific Extended Community attribute SHALL be 483 considered malformed if its length is nonzero and is not a multiple 484 of 20. 486 An UPDATE message with a malformed IPv6 Address Specific Extended 487 Community attribute SHALL be handled using the approach of "treat-as- 488 withdraw". 490 Note that a BGP speaker MUST NOT treat an unrecognized IPv6 Address 491 Specific Extended Community Type or Sub-Type as an error. 493 5.11. ORIGINATOR_ID 495 The error handling of [RFC4456] is revised as follows. 497 o If the ORIGINATOR_ID attribute is received from an external 498 neighbor, it SHALL be discarded using the approach of "attribute 499 discard", or 501 o if received from an internal neighbor, it SHALL be considered 502 malformed if its length is not equal to 4. If malformed, the 503 UPDATE SHALL be handled using the approach of "treat-as-withdraw". 505 5.12. CLUSTER_LIST 507 The error handling of [RFC4456] is revised as follows. 509 o If the CLUSTER_LIST attribute is received from an external 510 neighbor, it SHALL be discarded using the approach of "attribute 511 discard", or 513 o if received from an internal neighbor, it SHALL be considered 514 malformed if its length is not a multiple 4. If malformed, the 515 UPDATE SHALL be handled using the approach of "treat-as-withdraw". 517 6. IANA Considerations 519 This document makes no request of IANA. 521 7. Security Considerations 523 This specification addresses the vulnerability of a BGP speaker to a 524 potential attack whereby a distant attacker can generate a malformed 525 optional transitive attribute that is not recognized by intervening 526 routers (which thus propagate the attribute unchecked) but that 527 causes session resets when it reaches routers that do recognize the 528 given attribute type. 530 In other respects, this specification does not change BGP's security 531 characteristics. 533 8. Acknowledgements 535 The authors wish to thank Juan Alcaide, Ron Bonica, Mach Chen, Andy 536 Davidson, Bruno Decraene, Rex Fernando, Jeff Haas, Joel Halpern, Dong 537 Jie, Akira Kato, Miya Kohno, Tony Li, Alton Lo, Shin Miyakawa, Tamas 538 Mondal, Jonathan Oddy, Tony Przygienda, Robert Raszuk, Yakov Rekhter, 539 Eric Rosen, Shyam Sethuram, Rob Shakir, Naiming Shen, Adam Simpson, 540 Ananth Suryanarayana, Kaliraj Vairavakkalai and Lili Wang for their 541 observations and discussion of this topic, and review of this 542 document. 544 9. References 546 9.1. Normative References 548 [RFC1997] Chandrasekeran, R., Traina, P., and T. Li, "BGP 549 Communities Attribute", RFC 1997, August 1996. 551 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 552 Requirement Levels", BCP 14, RFC 2119, March 1997. 554 [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway 555 Protocol 4 (BGP-4)", RFC 4271, January 2006. 557 [RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended 558 Communities Attribute", RFC 4360, February 2006. 560 [RFC4456] Bates, T., Chen, E., and R. Chandra, "BGP Route 561 Reflection: An Alternative to Full Mesh Internal BGP 562 (IBGP)", RFC 4456, April 2006. 564 [RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter, 565 "Multiprotocol Extensions for BGP-4", RFC 4760, January 566 2007. 568 [RFC5701] Rekhter, Y., "IPv6 Address Specific BGP Extended Community 569 Attribute", RFC 5701, November 2009. 571 [RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet 572 Autonomous System (AS) Number Space", RFC 6793, December 573 2012. 575 9.2. Informative References 577 [I-D.ietf-l2vpn-evpn] 578 Sajassi, A., Aggarwal, R., Bitar, N., Isaac, A., and J. 579 Uttaro, "BGP MPLS Based Ethernet VPN", draft-ietf-l2vpn- 580 evpn-06 (work in progress), March 2014. 582 [RFC7117] Aggarwal, R., Kamite, Y., Fang, L., Rekhter, Y., and C. 583 Kodeboniya, "Multicast in Virtual Private LAN Service 584 (VPLS)", RFC 7117, February 2014. 586 Authors' Addresses 588 Enke Chen (editor) 589 Cisco Systems, Inc. 591 Email: enkechen@cisco.com 593 John G. Scudder (editor) 594 Juniper Networks 596 Email: jgs@juniper.net 598 Pradosh Mohapatra 599 Sproute Networks 601 Email: mpradosh@yahoo.com 603 Keyur Patel 604 Cisco Systems, Inc. 606 Email: keyupate@cisco.com