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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) No issues found here. Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group D. Migault (Ed) 3 Internet-Draft Ericsson 4 Intended status: Standards Track V. Smyslov 5 Expires: September 5, 2015 ELVIS-PLUS 6 March 4, 2015 8 Cloning IKE SA in the Internet Key Exchange Protocol Version 2 (IKEv2) 9 draft-mglt-ipsecme-clone-ike-sa-04.txt 11 Abstract 13 This document considers a VPN End User establishing an IPsec SA with 14 a Security Gateway using the Internet Key Exchange Protocol Version 2 15 (IKEv2), where at least one of the peers has multiple interfaces or 16 where Security Gateway is a cluster with each node having its own IP 17 address. 19 With the current IKEv2 protocol, the outer IP addresses of the IPsec 20 SA are determined by those used by IKE SA. As a result using 21 multiple interfaces requires to set up an IKE SA on each interface, 22 or on each path if both the VPN Client and the Security Gateway have 23 multiple interfaces. Setting each IKE SA involves authentications 24 which might require multiple round trips as well as activity from the 25 VPN End User and thus would delay the VPN establishment. In addition 26 multiple authentications unnecessarily increase the load on the VPN 27 client and the authentication infrastructure. 29 This document presents the solution that allows to clone IKEv2 SA, 30 where an additional SA is derived from an existing one. The newly 31 created IKE SA is set without the IKEv2 authentication exchange. 32 This IKE SA can later be assigned to another interface or moved to 33 another cluster mode using MOBIKE protocol. 35 Status of This Memo 37 This Internet-Draft is submitted in full conformance with the 38 provisions of BCP 78 and BCP 79. 40 Internet-Drafts are working documents of the Internet Engineering 41 Task Force (IETF). Note that other groups may also distribute 42 working documents as Internet-Drafts. The list of current Internet- 43 Drafts is at http://datatracker.ietf.org/drafts/current/. 45 Internet-Drafts are draft documents valid for a maximum of six months 46 and may be updated, replaced, or obsoleted by other documents at any 47 time. It is inappropriate to use Internet-Drafts as reference 48 material or to cite them other than as "work in progress." 49 This Internet-Draft will expire on September 5, 2015. 51 Copyright Notice 53 Copyright (c) 2015 IETF Trust and the persons identified as the 54 document authors. All rights reserved. 56 This document is subject to BCP 78 and the IETF Trust's Legal 57 Provisions Relating to IETF Documents 58 (http://trustee.ietf.org/license-info) in effect on the date of 59 publication of this document. Please review these documents 60 carefully, as they describe your rights and restrictions with respect 61 to this document. Code Components extracted from this document must 62 include Simplified BSD License text as described in Section 4.e of 63 the Trust Legal Provisions and are provided without warranty as 64 described in the Simplified BSD License. 66 Table of Contents 68 1. Requirements notation . . . . . . . . . . . . . . . . . . . . 2 69 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 70 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 71 4. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 5 72 5. Protocol Details . . . . . . . . . . . . . . . . . . . . . . 6 73 5.1. Support Negotiation . . . . . . . . . . . . . . . . . . . 6 74 5.2. Cloning the IKE SA . . . . . . . . . . . . . . . . . . . 6 75 5.3. Error Handling . . . . . . . . . . . . . . . . . . . . . 7 76 6. Payload Description . . . . . . . . . . . . . . . . . . . . . 7 77 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 78 8. Security Considerations . . . . . . . . . . . . . . . . . . . 8 79 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9 80 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 81 10.1. Normative References . . . . . . . . . . . . . . . . . . 9 82 10.2. Informational References . . . . . . . . . . . . . . . . 10 83 Appendix A. Setting a VPN on Multiple Interfaces . . . . . . . . 10 84 A.1. Setting VPN_0 . . . . . . . . . . . . . . . . . . . . . . 10 85 A.2. Creating an additional IKE SA . . . . . . . . . . . . . . 11 86 A.3. Creating the Child SA for VPN_1 . . . . . . . . . . . . . 12 87 A.4. Moving VPN_1 on Interface_1 . . . . . . . . . . . . . . . 13 88 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 90 1. Requirements notation 92 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 93 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 94 document are to be interpreted as described in [RFC2119]. 96 2. Introduction 98 The main scenario that motivated this document is a VPN End User 99 establishing VPN with a Security Gateway when at least one of the 100 peers has multiple interfaces. Figure 1 represents the case when the 101 VPN End User has multiple interfaces, Figure 2 represents the case 102 when the Security Gateway has multiple interfaces, and Figure 3 103 represents the case when both the VPN End User and the Security 104 Gateway have multiple interfaces. With Figure 1 and Figure 2, one of 105 the peers has n = 2 interfaces and the other has a single interface. 106 This results in creating of up to n = 2 VPNs. With Figure 3, the VPN 107 End User has n = 2 interfaces and the Security Gateway has m = 2 108 interfaces. This may lead to up to m x n VPNs. 110 +------------+ +------------+ 111 | | Interface_0 : VPN_0 | | 112 | ================= | | 113 | VPN | v | Security | 114 | End User | ================== Gateway | 115 | ================^ | | 116 | | Interface_1 : VPN_1 | | 117 +------------+ +------------+ 119 Figure 1: VPN End User with Multiple Interfaces 121 +------------+ +------------+ 122 | | Interface_0 : VPN_0 | | 123 | | ================== | 124 | VPN | v | Security | 125 | End User ================= | Gateway | 126 | | ^================= | 127 | | Interface_1 : VPN_1 | | 128 +------------+ +------------+ 130 Figure 2: Security Gateway with Multiple Interfaces 132 +------------+ +------------+ 133 | | Interface_0 Interface_0' | | 134 | ================================== | 135 | VPN | \\ // | Security | 136 | End User | // \\ | Gateway | 137 | ================================== | 138 | | Interface_1 Interface_1' | | 139 +------------+ +------------+ 141 Figure 3: VPN End User and Security Gateway with Multiple Interfaces 143 With the current IKEv2 protocol [RFC7296], each VPN requires an IKE 144 SA, and setting an IKE SA requires an authentication. Authentication 145 might require multiple round trips and an activity from the End User 146 (like EAP-SIM [RFC4186] or EAP-TLS [RFC5216]) as well as crypto 147 operations that would introduce an additional delay. 149 Another scenario is a load-balancing solution, when there are two or 150 more Security Gateways sharing the same ID, but each having its own 151 IP address. In this case the VPN End User first establishes IKE SA 152 with one of these gateways. Then, at some point of time the gateway 153 takes a decision to move client to a different cluster node. This 154 can be done using Redirect Mechanism for IKEv2 [RFC5685]. The 155 drawback of such approach is that it requires new IKE SA to be 156 established from scratch, including full authentication. In some 157 cases this could be avoided by using IKEv2 Session Resumption 158 [RFC5723] with a new gatevay. However this requires VPN End User to 159 know beforehand which new gateway to connect. It is desirable to be 160 able to clone existing IKE SA and moves it to a different Security 161 Gateway, and then indicate to VPN End User to use this new SA. This 162 would allows participating Security Gateways to share the load 163 between them. 165 This document introduces the possibility to clone the IKE SA in the 166 Internet Key Exchange Protocol Version 2 (IKEv2). The main idea is 167 that the peer with multiple interfaces sets the first IKE SA as 168 usual. Then it takes advantage of the fact that this SA is completed 169 and derives as many new parallel IKE SAs from it as the desired 170 number of VPNs. On each IKE SA a VPN is negotiated by creating one 171 or more IPsec SAs. This results in coexisting parallel VPNs. Then 172 the VPN End User moves each IPsec SA to its proper location using 173 MOBIKE protocol [RFC4555]. Alternatively, the VPN End User may first 174 move the IKE SAs and then create the IPsec SAs. 176 The combination of the IKE SA cloning with with MOBIKE protocol 177 provides IPsec communications with multiple interfaces the following 178 advantages. First, cloning the IKE SA requires very few 179 modifications to already existing IKEv2 implementations. Then, it 180 takes advantage of already existing and widely deployed MOBIKE 181 protocol. Finally, it keeps a dedicated IKE SA for each VPN which 182 simplifies reachability tests and VPN maintenance. 184 Note also that the cloning of the IKE SA is independent from MOBIKE 185 and can also address other future scenarios. 187 3. Terminology 189 This section defines terms and acronyms used in this document. 191 - VPN: Virtual Private Network - one or more Child (IPsec) SAs 192 created in tunnel mode between two peers. 194 - VPN End User: designates the end user that initiates the VPN with 195 a Security Gateway. This end user may be mobile and moves its 196 VPN from one Security Gateway to another. 198 - Security Gateway: designates a point of attachment for the VPN 199 service. In this document, the VPN service is provided by 200 multiple Security Gateways. Each Security Gateway may be 201 considered as a specific hardware. 203 - IKE SA: The IKE SA (IKE Security Association) is defined in 204 [RFC7296]. 206 4. Protocol Overview 208 The goal of the document is to specify how to create a new IKE SA 209 without performing an authentication. In order to achieve this goal, 210 the document proposes that the two peers agree upon their ability of 211 cloning the IKE SA. This is done during the IKE_AUTH exchange by 212 exchanging the CLONE_IKE_SA_SUPPORTED notifications. To create a new 213 parallel IKE SA, one of the peers initiates a CREATE_CHILD_SA 214 exchange as if it would rekey the existing IKE SA. In order to 215 indicate the current IKE SA must not be deleted, the initiator 216 includes the CLONE_IKE_SA notification in the CREATE_CHILD_SA 217 exchange. This results in two parallel IKE SAs. 219 Note, that without the CLONE_IKE_SA notification the old IKE SA would 220 be deleted after the rekey is successfully completed (as specified in 221 Section 2.8 of [RFC7296]. 223 5. Protocol Details 225 5.1. Support Negotiation 227 The initiator and the responder indicate their support for cloning 228 IKE SA by exchanging the CLONE_IKE SA_SUPPORTED notifications. This 229 notification MUST be sent in the IKE_AUTH exchange (in case of 230 multiple IKE_AUTH exchanges, in the message containing the SA 231 payload). If both initiator and responder send this notification 232 during the IKE_AUTH exchange, peers may clone this IKE SA. In the 233 other case the IKE SA MUST NOT be cloned. 235 Initiator Responder 236 ------------------------------------------------------------------- 237 HDR, SA, KEi, Ni --> 238 <-- HDR, SA, KEr, Nr 239 HDR, SK {IDi, AUTH, 240 SA, TSi, TSr, 241 N(CLONE_IKE_SA_SUPPORTED)} --> 242 <-- HDR, SK {IDr, AUTH, 243 SA, TSi, TSr, 244 N(CLONE_IKE_SA_SUPPORTED)} 246 5.2. Cloning the IKE SA 248 The initiator of the rekey exchange includes the CLONE_IKE_SA 249 notification in a CREATE_CHILD_SA request for rekeying the IKE SA. 250 The CLONE_IKE_SA notification indicates that the current IKE SA will 251 not be immediately deleted once the new IKE SA is created. Instead 252 two parallel IKE SAs are expected to coexist. The current IKE SA 253 becomes the old IKE SA and the newly negotiated IKE SA becomes the 254 new IKE SA. The CLONE_IKE_SA notification MUST appear only in 255 request message of the CREATE_CHILD_SA exchange concerning the IKE SA 256 rekey. If the CLONE_IKE_SA notification appears in any other 257 message, it MUST be ignored. 259 Initiator Responder 260 ------------------------------------------------------------------- 261 HDR, SK {N(CLONE_IKE_SA), SA, Ni, KEi} --> 263 If the CREATE_CHILD_SA request concerns an IKE SA rekey and contains 264 the CLONE_IKE_SA notification, the responder proceeds to the IKE SA 265 rekey, creates the new IKE SA, and keeps the old IKE SA. No 266 additional Notify Payload is included in the CREATE_CHILD_SA response 267 as represented below: 269 <-- HDR, SK {SA, Nr, KEr} 271 When the IKE SA is cloned, peers MUST NOT transfer existing Child 272 SAs, that were created by the old IKE SA, to the newly created IKE 273 SA. So, all signalling messages, concerning those Child SAs would 274 continue to be sent over the old IKE SA. This is different from the 275 regular IKE SA rekey in IKEv2. 277 5.3. Error Handling 279 There may be conditions when responder for some reason is unable or 280 unwilling to clone IKE SA. This inability may be temporary or 281 permanent. 283 Temporary inability occurs when responder doesn't have enough 284 resources at the moment to clone IKE SA or when IKE SA is being 285 deleted by responder. In this case the responder SHOULD reject the 286 request to clone IKE SA with the TEMPORARY_FAILURE notification. 288 <-- HDR, SK {N(TEMPORARY_FAILURE)} 290 After receiving this notification the initiator MAY retry its request 291 after waiting some period of time. See Section 2.25 of [RFC7296] for 292 details. 294 In some cases responder may have restrictions on the number of co- 295 existing IKE SAs with one peer. These restrictions may be either 296 implicit (some devices may have enough resources to handle only a few 297 IKE SAs) or explicit (provided by some configuration parameter). If 298 the initiator wants to clone more IKE SAs, than responder is able or 299 is configured to handle, the responder SHOULD reject the request with 300 the NO_ADDITIONAL_SAS notification. 302 <-- HDR, SK {N(NO_ADDITIONAL_SAS)} 304 This condition is considered permanent and the initiator SHOULD NOT 305 retry to clone IKE SA until some of existing SAs with the responder 306 are deleted. 308 6. Payload Description 310 Figure 4 illustrates the Notify Payload packet format as described in 311 section 3. 10 of [RFC7296]. This format is used for both the 312 CLONE_IKE_SA and the CLONE_IKE_SA_SUPPORTED notifications. 314 The CLONE_IKE_SA_SUPPORTED notification is used in an IKEv2 exchange 315 of type IKE_AUTH and the CLONE_IKE_SA is used in an IKEv2 exchange of 316 type CREATE_CHILD_SA. 318 1 2 3 319 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 1 320 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 321 | Next Payload |C| RESERVED | Payload Length | 322 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 323 | Protocol ID | SPI Size | Notify Message Type | 324 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 326 Figure 4: Notify Payload 328 The fields Next Payload, Critical Bit, RESERVED and Payload Length 329 are defined in [RFC7296]. Specific fields defined in this document 330 are: 332 - Protocol ID (1 octet): set to zero. 334 - SPI Size (1 octet): set to zero. 336 - Notify Message Type (2 octets): Specifies the type of notification 337 message. It is set to for the CLONE_IKE_SA 338 notification or to for the CLONE_IKE_SA_SUPPORTED 339 Notification. 341 7. IANA Considerations 343 IANA is requested to allocate two values in the "IKEv2 Notify Message 344 Types - Status Types registry": 346 IKEv2 Notify Message Types - Status Types 347 ----------------------------------------- 348 CLONE_IKE_SA_SUPPORTED 349 CLONE_IKE_SA 351 8. Security Considerations 353 The protocol defined in this document does not modify IKEv2. 354 Security considerations for cloning an IKE SA are mostly the same as 355 those for base IKEv2 protocol described in [RFC7296]. 357 Cloning an IKE SA provides the ability for an initiator to duplicate 358 existing SAs. As a result it may influence any accounting or control 359 mechanisms based on a single IKE SA per authentication. 361 Suppose a system has a limit on the number of IKE SAs it can handle. 362 In this case, the cloning an IKE SA may provide a way for resource 363 exhaustion, as a single end user may populate multiple IKE SAs. 365 Suppose a system shares the IPsec resources by limiting the number of 366 Child SAs per IKE SA. With a single IKE SA per end user, this 367 provides an equal resource sharing. In this case, cloning the IKE SA 368 provides means for an end user to overpass this limit. Such system 369 should evaluate the number of Child SAs over the number of all IKE 370 SAs associated to an end user. 372 Note, that these issues are not unique to the ability of cloning the 373 IKE SA, as multiple IKE SAs between two peers may be created without 374 involving a cloning method. Note also, that implementation can 375 always limit the number of cloned IKE SAs. 377 Suppose VPN or any other IPsec based service monitoring is based on 378 the liveliness of the first IKE SA. Such system considers a service 379 is accessed or used from the time IKE performs an authentication to 380 the time the IKE SA is deleted. Such accounting methods were fine as 381 any IKE SA required an authentication exchange. As cloning the IKE 382 SA skips the authentication phase, it may make possible to delete the 383 initial IKE SA while the service is being used on the cloned IKE SA. 384 Such accountings method should considers the service is being used 385 from the first IKE SA establishment to until the last IKE SA is being 386 removed. 388 9. Acknowledgments 390 The ideas of this draft came from various inputs from the ipsecme WG 391 and from discussions with Tero Kivinen and Michael Richardson. Yaron 392 Sheffer, Tero Kivinen provided significant inputs to set the current 393 design of the protocol as well as its designation. 395 10. References 397 10.1. Normative References 399 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 400 Requirement Levels", BCP 14, RFC 2119, March 1997. 402 [RFC4555] Eronen, P., "IKEv2 Mobility and Multihoming Protocol 403 (MOBIKE)", RFC 4555, June 2006. 405 [RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T. 406 Kivinen, "Internet Key Exchange Protocol Version 2 407 (IKEv2)", STD 79, RFC 7296, October 2014. 409 10.2. Informational References 411 [RFC4186] Haverinen, H. and J. Salowey, "Extensible Authentication 412 Protocol Method for Global System for Mobile 413 Communications (GSM) Subscriber Identity Modules (EAP- 414 SIM)", RFC 4186, January 2006. 416 [RFC5216] Simon, D., Aboba, B., and R. Hurst, "The EAP-TLS 417 Authentication Protocol", RFC 5216, March 2008. 419 [RFC5685] Devarapalli, V. and K. Weniger, "Redirect Mechanism for 420 the Internet Key Exchange Protocol Version 2 (IKEv2)", RFC 421 5685, November 2009. 423 [RFC5723] Sheffer, Y. and H. Tschofenig, "Internet Key Exchange 424 Protocol Version 2 (IKEv2) Session Resumption", RFC 5723, 425 January 2010. 427 Appendix A. Setting a VPN on Multiple Interfaces 429 This section is informational and exposes how a VPN End User as 430 illustrated in Figure 1 can build two VPNs on its two interfaces 431 without multiple authentications. Other cases represented in 432 Figure 2 and Figure 3 are similar and can be easily derived from this 433 case. The mechanism is based on cloning the IKE SA and the MOBIKE 434 extension [RFC4555]. 436 A.1. Setting VPN_0 438 First, the VPN End User negotiates a VPN using one interface. This 439 involves regular IKEv2 exchanges. In addition, the VPN End User and 440 the Security Gateway advertise their support for MOBIKE. At the end 441 of the IKE_AUTH exchange, VPN_0 is set as represented in Figure 5. 443 +------------+ +------------+ 444 | | Interface_0 : VPN_0 | | 445 | ================= | | 446 | VPN | v | Security | 447 | End User | ================== Gateway | 448 | = | | 449 | | Interface_1 | | 450 +------------+ +------------+ 452 Figure 5: VPN End User Establishing VPN_0 454 The exchanges are completely described in [RFC7296] and [RFC4555]. 455 First, peers negotiate IKE SA parameters and exchange nonces and 456 public keys in IKE_SA_INIT exchange. In the figure below they also 457 proceed to NAT detection because of the use of MOBIKE. 459 Initiator Responder 460 ------------------------------------------------------------------- 461 (IP_I0:500 -> IP_R:500) 462 HDR, SA, KEi, Ni, 463 N(NAT_DETECTION_SOURCE_IP), 464 N(NAT_DETECTION_DESTINATION_IP) --> 466 <-- (IP_R:500 -> IP_I0:500) 467 HDR, SA, KEr, Nr, 468 N(NAT_DETECTION_SOURCE_IP), 469 N(NAT_DETECTION_DESTINATION_IP) 471 Then the initiator and the responder proceed to the IKE_AUTH 472 exchange, advertise their support for MOBIKE and their ability to 473 clone the IKE SA - with the MOBIKE_SUPPORTED and the 474 CLONE_IKE_SA_SUPPORTED notifications - and negotiate the Child SA for 475 VPN_0. Optionally, the initiator and the responder can advertise 476 their multiple interfaces using the ADDITIONAL_IP4_ADDRESS and/or 477 ADDITIONAL_IP6_ADDRESS notifications. 479 (IP_I0:4500 -> IP_R:4500) 480 HDR, SK {IDi, AUTH, 481 SA, TSi, TSr, 482 N(MOBIKE_SUPPORTED), 483 [N(ADDITIONAL_IP*_ADDRESS)+,] 484 N(CLONE_IKE_SA_SUPPORTED)} --> 486 <-- (IP_R:4500 -> IP_I0:4500) 487 HDR, SK {IDr, AUTH, 488 SA, TSi, TSr, 489 N(MOBIKE_SUPPORTED), 490 [N(ADDITIONAL_IP*_ADDRESS)+,] 491 N(CLONE_IKE_SA_SUPPORTED)} 493 A.2. Creating an additional IKE SA 495 In our case the VPN End User wants to establish an additional VPN 496 with its Interface_1. The VPN End User will first establish a 497 parallel IKE SA using a CREATE_CHILD_SA that concerns an IKE SA rekey 498 associated with a CLONE_IKE_SA notification. This results in two 499 separate IKE SAs between the VPN End User and the Security Gateway. 500 Currently both IKE SAs are set using Interface_0 of the VPN End User. 502 Initiator Responder 503 ------------------------------------------------------------------- 504 (IP_I0:4500 -> IP_R:4500) 505 HDR, SK {N(CLONE_IKE_SA), 506 SA, Ni, KEi} --> 507 <-- (IP_R:4500 -> IP_I0:4500) 508 HDR, SK {SA, Nr, KEr} 510 A.3. Creating the Child SA for VPN_1 512 Once the new IKE SA has been created, the VPN End User can initiate a 513 CREATE_CHILD_SA exchange that concerns the creation of a Child SA for 514 VPN_1. The newly created VPN_1 will use Interface_0 of the VPN End 515 User. 517 It is out of scope of the document to define how the VPN End User 518 handles traffic with multiple interfaces. The VPN End User can use 519 the same inner IP address on its multiple interfaces. In this case, 520 the same Traffic Selectors (that is the IP address used for VPN_0 and 521 VPN_1) can match for both VPNs VPN_0 and VPN_1. The VPN End User 522 must be aware of such match and be able to manage it. It can for 523 example use distinct Traffic Selectors on both VPNs using different 524 ports, manage the order of its SPD or have SPD defined per 525 interfaces. Defining these mechanisms are out of scope of this 526 document. Alternatively, the VPN End User can use a different inner 527 IP address for each interface. 529 The creation of VPN_1 is performed via the newly created IKE SA as 530 follows: 532 Initiator Responder 533 ------------------------------------------------------------------- 534 (IP_I0:4500 -> IP_R:4500) 535 HDR(new), SK(new) {SA, TSi, TSr} --> 537 <-- (IP_R:4500 -> IP_I0:4500) 538 HDR(new), SK(new) {SA, TSi, TSr} 540 The resulting configuration is depicted in Figure 6. VPN_0 and VPN_1 541 have been created, but both are using the same Interface: 542 Interface_0. 544 +------------+ +------------+ 545 | | Interface_0 : VPN_0, VPN_1 | | 546 | ==================== | | 547 | VPN ================= v | Security | 548 | End User | v =============== Gateway | 549 | | ================== | 550 | | Interface_1 | | 551 +------------+ +------------+ 553 Figure 6: VPN End User Establishing VPN_0 and VPN_1 555 A.4. Moving VPN_1 on Interface_1 557 In this section, MOBIKE is used to move VPN_1 on interface_1. The 558 exchange is described in [RFC4555]. 560 (IP_I1:4500 -> IP_R:4500) 561 HDR(new), SK(new) {N(UPDATE_SA_ADDRESSES), 562 N(NAT_DETECTION_SOURCE_IP), 563 N(NAT_DETECTION_DESTINATION_IP), 564 N(COOKIE2)} --> 566 <-- (IP_R:4500 -> IP_I1:4500) 567 HDR(new), SK(new) { 568 N(NAT_DETECTION_SOURCE_IP), 569 N(NAT_DETECTION_DESTINATION_IP), 570 N(COOKIE2)} 572 This results in the situation as described in Figure 7. 574 +------------+ +------------+ 575 | | Interface_0 : VPN_0 | | 576 | ================== | | 577 | VPN | v | Security | 578 | End User | ================= Gateway | 579 | =================^ | | 580 | | Interface_1 : VPN_1 | | 581 +------------+ +------------+ 583 Figure 7: VPN End User with Multiple Interfaces 585 Authors' Addresses 586 Daniel Migault 587 Ericsson 588 8400 boulevard Decarie 589 Montreal, QC H4P 2N2 590 Canada 592 Email: mglt.ietf@gmail.com 594 Valery Smyslov 595 ELVIS-PLUS 596 PO Box 81 597 Moscow (Zelenograd) 124460 598 Russian Federation 600 Phone: +7 495 276 0211 601 Email: svan@elvis.ru