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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) ** Obsolete normative reference: RFC 4306 (ref. '2') (Obsoleted by RFC 5996) -- Obsolete informational reference (is this intentional?): RFC 3775 (ref. '3') (Obsoleted by RFC 6275) Summary: 2 errors (**), 0 flaws (~~), 2 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group V. Devarapalli 3 Internet-Draft WiChorus 4 Intended status: Standards Track K. Weniger 5 Expires: September 24, 2009 March 23, 2009 7 Redirect Mechanism for IKEv2 8 draft-ietf-ipsecme-ikev2-redirect-06.txt 10 Status of this Memo 12 This Internet-Draft is submitted to IETF in full conformance with the 13 provisions of BCP 78 and BCP 79. This document may not be modified, 14 and derivative works of it may not be created, except to format it 15 for publication as an RFC or to translate it into languages other 16 than English. 18 Internet-Drafts are working documents of the Internet Engineering 19 Task Force (IETF), its areas, and its working groups. Note that 20 other groups may also distribute working documents as Internet- 21 Drafts. 23 Internet-Drafts are draft documents valid for a maximum of six months 24 and may be updated, replaced, or obsoleted by other documents at any 25 time. It is inappropriate to use Internet-Drafts as reference 26 material or to cite them other than as "work in progress." 28 The list of current Internet-Drafts can be accessed at 29 http://www.ietf.org/ietf/1id-abstracts.txt. 31 The list of Internet-Draft Shadow Directories can be accessed at 32 http://www.ietf.org/shadow.html. 34 This Internet-Draft will expire on September 24, 2009. 36 Copyright Notice 38 Copyright (c) 2009 IETF Trust and the persons identified as the 39 document authors. All rights reserved. 41 This document is subject to BCP 78 and the IETF Trust's Legal 42 Provisions Relating to IETF Documents in effect on the date of 43 publication of this document (http://trustee.ietf.org/license-info). 44 Please review these documents carefully, as they describe your rights 45 and restrictions with respect to this document. 47 Abstract 49 IKEv2 is a protocol for setting up VPN tunnels from a remote location 50 to a gateway so that the VPN client can access services in the 51 network behind the gateway. Currently there is no standard mechanism 52 specified that allows an overloaded VPN gateway or a VPN gateway that 53 is being shut down for maintenance to redirect the VPN client to 54 attach to another gateway. This document proposes a redirect 55 mechanism for IKEv2. The proposed mechanism can also be used in 56 Mobile IPv6 to enable the home agent to redirect the mobile node to 57 another home agent. 59 Table of Contents 61 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 62 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 63 3. IKEv2 Exchange with Redirect . . . . . . . . . . . . . . . . . 4 64 4. Use of Anycast Addresses with the Redirect Mechanism . . . . . 5 65 5. Gateway Initiated Redirect . . . . . . . . . . . . . . . . . . 6 66 6. Redirect Messages . . . . . . . . . . . . . . . . . . . . . . 7 67 6.1. REDIRECT_SUPPORTED . . . . . . . . . . . . . . . . . . . . 8 68 6.2. REDIRECT . . . . . . . . . . . . . . . . . . . . . . . . . 8 69 6.3. REDIRECTED_FROM . . . . . . . . . . . . . . . . . . . . . 9 70 7. Use of the Redirect Mechanism between IKEv2 Peers . . . . . . 10 71 8. Security Considerations . . . . . . . . . . . . . . . . . . . 10 72 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 73 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11 74 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12 75 11.1. Normative References . . . . . . . . . . . . . . . . . . . 12 76 11.2. Informative References . . . . . . . . . . . . . . . . . . 12 77 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12 79 1. Introduction 81 IKEv2 [2] is used for setting up IPsec-based VPNs. The IP address of 82 the VPN gateway can be configured on the VPN client. But this does 83 not scale well, when the number of VPN gateways is large. Dynamic 84 discovery of VPN gateways using DNS is quite widely used too. 85 However, using DNS is not flexible when it comes to assigning a VPN 86 gateway to the VPN client based on the load on the VPN gateways. The 87 VPN client typically tries to connect to the IP address of the VPN 88 gateways that appears first in the DNS response. If the VPN tunnel 89 setup fails, then the VPN client tries to attach to the other VPN 90 gateways returned in the DNS response. 92 This document proposes a redirect mechanism for IKEv2 that enables a 93 VPN gateway to redirect the VPN client to another VPN gateway, for 94 example, based on the load condition. The redirect can be done 95 during during the IKE_SA_INIT or the IKE_AUTH exchange. Gateway- 96 initiated redirect in the middle of a session is also supported. The 97 redirect mechanism can also be used in conjunction with anycast 98 addresses. In this case, anycast address for the cluster of VPN 99 gateways is stored in the DNS instead of a list of unicast IP 100 addresses of the VPN gateways. 102 The redirect can also happen because of administrative or optimal 103 routing reasons. This document does not attempt to provide an 104 exhaustive list of reasons for redirecting a VPN client to another 105 VPN gateway. 107 Mobile IPv6 [3] may use IKEv2 for mutual authentication between the 108 mobile node and the home agent. IKEv2 may also be used for home 109 address configuration and setting up IPsec security associations for 110 protecting Mobile IPv6 signaling messages [4]. The IKEv2 exchange 111 precedes the exchange of Mobile IPv6 signaling messages. Therefore 112 the mechanism described in this document can be also be used by a 113 Mobile IPv6 home agent to redirect a mobile node to another home 114 agent. 116 There is a Home Agent Switch mechanism available for redirecting a 117 mobile node to another home agent, described in [5]. The Home Agent 118 Switch mechanism can only be used after the binding cache had been 119 created at the home agent for the mobile node. The disadvantage with 120 this is that quite a bit of state is created on the home agent before 121 the mobile node can be redirected to another home agent. The 122 mechanism described in this document can be used for redirecting a 123 mobile node before any state related to the Mobile IPv6 binding is 124 created on the home agent. 126 2. Terminology 128 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 129 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 130 document are to be interpreted as described in [1]. 132 3. IKEv2 Exchange with Redirect 134 To redirect an IKEv2 session to another VPN gateway, the VPN gateway 135 that initially received the IKE_SA_INIT request selects another VPN 136 gateway and responds to the VPN client with a REDIRECT Notification 137 payload. The mechanism by which the initial VPN gateway selects 138 another VPN gateway is out of scope for this document. The IP 139 address of the selected VPN gateway is sent in the REDIRECT payload. 140 The gateway MUST include the nonce data from the Ni payload sent by 141 the initiator in the REDIRECT payload. This prevents certain Denial- 142 of-Service attacks on the initiator that could be caused by an 143 attacker injecting IKE_SA_INIT responses with REDIRECT payloads. 145 The VPN client indicates support for the IKEv2 redirect mechanism by 146 including a REDIRECT_SUPPORTED notification message in the initial 147 IKE_SA_INIT request. If the IKE_SA_INIT request did not include the 148 REDIRECT_SUPPORTED payload, the responder MUST NOT send the REDIRECT 149 payload to the VPN client. 151 Initiator Responder (initial VPN GW) 152 --------- ------------------------- 154 (IP_I:500 -> Initial_IP_R:500) 155 HDR(A,0), SAi1, KEi, Ni, --> 156 N(REDIRECT_SUPPORTED) 158 (Initial_IP_R:500 -> IP_I:500) 159 <-- HDR(A,0), N(REDIRECT, IP_R) 161 When the VPN client receives the IKE_SA_INIT response with the 162 REDIRECT payload, it initiates a new IKE_SA_INIT exchange with the 163 VPN gateway listed in the REDIRECT payload. The VPN client includes 164 the IP address of the original VPN gateway that redirected the 165 client. The IKEv2 exchange then proceeds as normal with the selected 166 VPN gateway. 168 Initiator Responder (Selected VPN GW) 169 --------- --------------------------- 171 (IP_I:500 -> IP_R:500) 172 HDR(A,0), SAi1, KEi, Ni, --> 173 N(REDIRECTED_FROM, Initial_IP_R) 175 (IP_R:500 -> IP_I:500) 176 <-- HDR(A,B), SAr1, KEr, Nr,[CERTREQ] 178 (IP_I:500 -> IP_R:500) 179 HDR(A,B), SK {IDi, [CERT,] [CERTREQ,] 180 [IDr,]AUTH, SAi2, TSi, TSr} --> 182 (IP_R:500 -> IP_I:500) 183 <-- HDR(A,B), SK {IDr, [CERT,] AUTH, 184 SAr2, TSi, TSr} 186 When this mechanism is used with Mobile IPv6, a mobile node's 187 security associations with its home agent may expire while it still 188 has a valid binding cache entry at the home agent. In this case, the 189 mobile node MUST NOT use the original home agent address as the 190 destination address in the IKE_SA_INIT exchange to setup new security 191 associations. It MUST try to setup security associations with its 192 existing home agent. 194 4. Use of Anycast Addresses with the Redirect Mechanism 196 The use of anycast addresses will avoid having to configure a 197 particular VPN gateway's IP address in the DNS. Instead, the anycast 198 address that represents the group of VPN gateways is stored in the 199 DNS. When the VPN client performs a DNS lookup for the VPN gateway, 200 it receives the anycast address of the VPN gateway in the DNS 201 response. 203 If an anycast address is returned in response to DNS resolution of an 204 FQDN, the VPN client sends the IKE_SA_INIT request to the anycast 205 address. The IKE_SA_INIT request is routed to one of the VPN 206 gateways that is part of the anycast group. The VPN gateway that 207 receives the IKE_SA_INIT request responds with an IKE_SA_INIT reply 208 from the anycast address. 210 Initiator Responder (any VPN GW) 211 --------- ------------------------- 213 (IP_I:500 -> ANYCAST:500) 214 HDR(A,0), SAi1, KEi, Ni) --> 215 N(REDIRECT_SUPPORTED) 217 (ANYCAST:500 -> IP_I:500) 218 <-- HDR(A,0), N(REDIRECT, IP_R) 220 If the destination address on the IKE_SA_INIT request is an anycast 221 address, the VPN gateway that received the IKE_SA_INIT request MUST 222 include the REDIRECT payload to redirect the VPN client to a unicast 223 address of one of the VPN gateway. The VPN gateway that received the 224 IKE_SA_INIT request MAY redirect the client to its own unicast 225 address, if it is not overloaded. 227 The rest of the IKEv2 exchange is the same as described in Section 3. 229 5. Gateway Initiated Redirect 231 The redirect mechanism may also be used by a VPN gateway to redirect 232 the client to another VPN gateway in middle of a session. To 233 redirect a client, the gateway should send an INFORMATIONAL message 234 with the REDIRECT Notify payload. The REDIRECT payload MUST carry 235 information about the new VPN gateway. The gateway MUST NOT include 236 any nonce data in the REDIRECT payload, since it is a gateway- 237 initiated message and is protected by the IKEv2 security association. 238 When the client receives this message, it MUST send an empty message 239 as an acknowledgement. Until the client responds with an 240 acknowledgement, the gateway SHOULD re-transmit the redirect 241 INFORMATIONAL message as described in [2]. The following illustrates 242 the INFORMATIONAL message exchange for gateway-initiated redirect. 244 Initiator (VPN client) Responder (VPN GW) 245 ---------------------- ------------------ 247 <-- HDR, SK {N[REDIRECT, IP_R/FQDN_R]} 249 HDR, SK {} --> 251 The INFORMATIONAL message exchange described above is protected by 252 the existing IKEv2 SA between the client and the gateway. 254 Once the client sends an acknowledgement to the gateway, it SHOULD 255 delete the existing security associations with the old gateway by 256 sending an Informational message with a DELETE payload. The gateway 257 MAY also decide to delete the security associations without any 258 signaling from the client, again by sending an Informational message 259 with a DELETE payload. However, it should allow sufficient time for 260 the client to setup the required security associations with the new 261 security gateway. This time period should be configurable on the 262 gateway. 264 If the gateway decides to redirect the client during the IKE_AUTH 265 exchange, based on the identity presented by the client in the 266 IKE_AUTH request message, it prevents the creation of a CHILD SA and 267 sends the REDIRECT payload in the IKE_AUTH response. When the client 268 receives the IKE_AUTH response with the REDIRECT payload, it SHOULD 269 delete the existing IKEv2 security association with the gateway. 271 Initiator Responder ( VPN GW) 272 --------- ------------------- 274 (IP_I:500 -> IP_R:500) 275 HDR(A,0), SAi1, KEi, Ni, --> 276 N(REDIRECTED_SUPPORTED) 278 (IP_R:500 -> IP_I:500) 279 <-- HDR(A,B), SAr1, KEr, Nr,[CERTREQ] 281 (IP_I:500 -> IP_R:500) 282 HDR(A,B), SK {IDi, [CERT,] [CERTREQ,] 283 [IDr,]AUTH, SAi2, TSi, TSr} --> 285 (IP_R:500 -> IP_I:500) 286 <-- HDR(A,B), SK {IDr, [CERT,] AUTH, 287 N[REDIRECT, IP_R/FQDN_R]} 289 In case the IKE_AUTH exchange involves EAP authentication as 290 described in Section 2.16 of RFC 4306 [2] or multiple authentication 291 methods as described in RFC 4739 [6], the IKE_AUTH exchange is more 292 complicated. The identity presented by the client in the first 293 IKE_AUTH request might be a temporary one. In addition, the gateway 294 might decide to redirect the client based on the interaction with the 295 the AAA server, when EAP authentication is used or the external 296 authentication server, when multiple authentication methods are used. 297 In such cases, the exact message in which the gateway sends the 298 REDIRECT payload is TBD. 300 6. Redirect Messages 301 6.1. REDIRECT_SUPPORTED 303 The REDIRECT_SUPPORTED payload is included in the initial IKE_SA_INIT 304 request by the initiator to indicate support for the IKEv2 redirect 305 mechanism described in this document. 307 1 2 3 308 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 1 309 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 310 | Next Payload |C| RESERVED | Payload Length | 311 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 312 | Protocol ID | SPI Size (=0) | Notify Message Type | 313 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 315 The 'Next Payload', 'Payload Length', 'Protocol ID', 'SPI Size' and 316 the 'Notify Message Type' fields are the same as described in Section 317 3.10 of [2]. The 'SPI Size' field MUST be set to 0 to indicate that 318 the SPI is not present in this message. The 'Protocol ID' MUST be 319 set to 0, since the notification is not specific to a particular 320 security association. 322 The 'Payload Length' field MUST be set to '8'. The 'Notify Message 323 Type' field is set to indicate the REDIRECT_SUPPORTED payload . 326 6.2. REDIRECT 328 The REDIRECT payload is included in an IKE_SA_INIT response from the 329 responder or an INFORMATIONAL message from the responder, when the 330 responder wants to redirect the initiator to another VPN gateway. 331 The message includes the new responder's IP address. 333 1 2 3 334 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 1 335 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 336 | Next Payload |C| RESERVED | Payload Length | 337 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 338 | Protocol ID | SPI Size (=0) | Notify Message Type | 339 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 340 | GW Ident Type | | 341 +---------------+ ~ 342 ~ New Responder GW Identity ~ 343 | | 344 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 345 | | 346 ~ Nonce Data ~ 347 | | 348 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 350 The 'Next Payload', 'Payload Length', 'Protocol ID', 'SPI Size' and 351 the 'Notify Message Type' fields are the same as described in Section 352 3.10 of [2]. The 'SPI Size' field MUST be set to 0 to indicate that 353 the SPI is not present in this message. The 'Protocol ID' MUST be 354 set to 0, since the notification is not specific to a particular 355 security association. 357 If the IP address of the new VPN gateway is sent, the 'Payload 358 Length' field MUST be set to either '13' or '25' depending on whether 359 an IPv4 or IPv6 address is sent in the message. If the FQDN of the 360 new VPN gateway is sent, the 'Payload Length' field is set to the 361 length of the FQDN plus the fixed fields in the message. The 'Notify 362 Message Type' field is set to indicate the REDIRECT payload . The 'GW Identity Type' field indicates the 364 type of information that is sent to identify the new VPN gateway. 365 The following values are reserved by this document. 367 1 - IPv4 address of the new VPN gateway 368 2 - IPv6 address of the new VPN gateway 369 3 - FQDN of the new VPN gateway 371 All other values for this field are reserved and MUST NOT be used. 372 The identity of the new VPN gateway is carried in the 'New Responder 373 GW Identity' field. 375 The 'Nonce Data' field carries the nonce data from the Ni payload 376 sent by the initiator. The size of the nonce MUST be between 16 and 377 256 bytes as described in Section 3.9 of [2]. The 'Nonce Data' field 378 is present in the REDIRECT payload only when the REDIRECT payload is 379 sent in the IKE_SA_INIT response message. It MUST NOT be included in 380 the REDIRECT payload if sent in an IKE_AUTH response or in a gateway- 381 initiated redirect message. 383 6.3. REDIRECTED_FROM 385 The REDIRECTED_FROM message type is included in the IKE_SA_INIT 386 request from the initiator to the new VPN gateway to indicate the IP 387 address of the original VPN gateway that redirected the initiator. 388 The original VPN gateway's IP address is included in the message. 390 1 2 3 391 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 1 392 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 393 | Next Payload |C| RESERVED | Payload Length | 394 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 395 | Protocol ID | SPI Size (=0) | Notify Message Type | 396 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 397 | GW Ident Type | | 398 +---------------+ ~ 399 ~ Original Responder GW Identity ~ 400 | | 401 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 403 The 'Next Payload', 'Payload Length', 'Protocol ID', 'SPI Size' and 404 the 'Notify Message Type' fields are the same as described in Section 405 3.10 of [2] The 'SPI Size' field MUST be set to 0 to indicate that 406 the SPI is not present in this message. The 'Protocol ID' MUST be 407 set to 0, since the notification is not specific to a particular 408 security association. 410 The 'Payload Length' field MUST be set to either '13' or '25' 411 depending on whether an IPv4 or IPv6 address of the original VPN 412 gateway is sent in the message. The 'Notify Message Type' field is 413 set to indicate the REDIRECTED_FROM payload . The 'GW Identity Type' field indicates the type of 415 information that is sent to identify the new VPN gateway. The 416 following values are reserved by this document. 418 1 - IPv4 address of the original VPN gateway 419 2 - IPv6 address of the original VPN gateway 421 All other values for this field are reserved and MUST NOT be used. 422 The identity of the original VPN gateway is carried in the 'Original 423 Responder GW Identity' field. 425 7. Use of the Redirect Mechanism between IKEv2 Peers 427 The Redirect mechanism described in this document is mainly intended 428 for use in client-gateway scenarios. However, the mechanism can also 429 be used between any two IKEv2 peers. But this protocol is 430 asymmetric, meaning that only the original responder can redirect the 431 original initiator to another server. 433 8. Security Considerations 435 An eavesdropper on the path between VPN client and server may send a 436 redirect to the client upon receiving an IKE_SA_INIT message from 437 this client. This is no problem regarding DoS attacks for the VPN 438 connection, since an on-path-attacker can as well drop the 439 IKE_SA_INIT requests to prevent VPN access for the client. But an 440 eavesdropper on the path between VPN client and server can redirect a 441 large number of clients to a victim, which is then flooded with 442 IKE_SA_INIT requests. Flooding only happens if many clients initiate 443 IKEv2 exchange at almost the same time, which is considered a rare 444 event. However, this may happen if a Home Agent/VPN server is 445 shutdown for maintenance and all clients need to re-establish VPN 446 connections with another Home Agent/VPN server or if the on-path 447 attacker forces all IPsec security associations to expire by dropping 448 all received IKEv2 messages. 450 The use of REDIRECTED_FROM payload is intended to discourage a rogue 451 VPN gateway from redirecting a large number of VPN clients to a 452 particular VPN gateway. It does not prevent such a DoS attack. 454 9. IANA Considerations 456 This document defines four new IKEv2 Notification Message types as 457 described in Section 6. The three Notify Message Types must be 458 assigned values between 16396 and 40959. 460 o REDIRECT_SUPPORTED 461 o REDIRECT 462 o REDIRECTED_FROM 464 10. Acknowledgements 466 The use of anycast address with IKEv2 was first described in [7]. It 467 was then added to an early draft version of RFC 5026 and later 468 removed before the RFC was published. Therefore the authors of [7] 469 and RFC 5026 are acknowledged. 471 Thanks to Pasi Eronen, with whom the solution described in this 472 document was extensively discussed. Thanks to Tero Kivinen for 473 suggesting the use of REDIRECTED_FROM payload and other comments 474 which helped improve the document. The authors would also like to 475 thank Yaron Sheffer, Sunil Kumar, Fan Zhao, Yoav Nir, Richard 476 Graveman, and Arnaud Ebalard for their reviews and comments. 478 11. References 479 11.1. Normative References 481 [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement 482 Levels", BCP 14, RFC 2119, March 1997. 484 [2] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol", RFC 4306, 485 December 2005. 487 11.2. Informative References 489 [3] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in 490 IPv6", RFC 3775, June 2004. 492 [4] Giaretta, G., Kempf, J., and V. Devarapalli, "Mobile IPv6 493 Bootstrapping in Split Scenario", RFC 5026, October 2007. 495 [5] Haley, B., Devarapalli, V., Deng, H., and J. Kempf, "Mobility 496 Header Home Agent Switch Message", RFC 5142, January 2008. 498 [6] Eronen, P. and J. Korhonen, "Multiple Authentication Exchanges 499 in the Internet Key Exchange (IKEv2) Protocol", RFC 4739, 500 November 2006. 502 [7] Weniger, K. and F. Dupont, "IKEv2-based Home Agent Assignment in 503 Mobile IPv6/NEMO Bootstrapping", draft-dupont-ikev2-haassign-02 504 (work in progress), January 2007. 506 Authors' Addresses 508 Vijay Devarapalli 509 WiChorus 510 3590 North First St 511 San Jose, CA 95134 512 USA 514 Email: vijay@wichorus.com 516 Kilian Weniger 518 Email: kilian.weniger@googlemail.com