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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 3315 (Obsoleted by RFC 8415) Summary: 1 error (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 DMM Working Group Z. Yan 3 Internet-Draft CNNIC 4 Intended status: Standards Track J. Lee 5 Expires: July 9, 2017 Sangmyung University 6 X. Lee 7 CNNIC 8 January 5, 2017 10 Home Network Prefix Renumbering in PMIPv6 11 draft-ietf-dmm-hnprenum-04 13 Abstract 15 In the basic Proxy Mobile IPv6 (PMIPv6) specification, a Mobile Node 16 (MN) is assigned with a Home Network Prefix (HNP) during its initial 17 attachment and the MN configures its Home Address (HoA) with the HNP. 18 During the movement of the MN, the HNP remains unchanged to keep 19 ongoing communications associated with the HoA. However, the current 20 PMIPv6 specification does not specify related operations when an HNP 21 renumbering is happened. In this document, a solution to support the 22 HNP renumbering is proposed, as an update of the PMIPv6 23 specification. 25 Requirements Language 27 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL","SHALL NOT", 28 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 29 document are to be interpreted as described in [RFC2119] 31 Status of This Memo 33 This Internet-Draft is submitted in full conformance with the 34 provisions of BCP 78 and BCP 79. 36 Internet-Drafts are working documents of the Internet Engineering 37 Task Force (IETF). Note that other groups may also distribute 38 working documents as Internet-Drafts. The list of current Internet- 39 Drafts is at http://datatracker.ietf.org/drafts/current/. 41 Internet-Drafts are draft documents valid for a maximum of six months 42 and may be updated, replaced, or obsoleted by other documents at any 43 time. It is inappropriate to use Internet-Drafts as reference 44 material or to cite them other than as "work in progress." 46 This Internet-Draft will expire on July 9, 2017. 48 Copyright Notice 50 Copyright (c) 2017 IETF Trust and the persons identified as the 51 document authors. All rights reserved. 53 This document is subject to BCP 78 and the IETF Trust's Legal 54 Provisions Relating to IETF Documents 55 (http://trustee.ietf.org/license-info) in effect on the date of 56 publication of this document. Please review these documents 57 carefully, as they describe your rights and restrictions with respect 58 to this document. Code Components extracted from this document must 59 include Simplified BSD License text as described in Section 4.e of 60 the Trust Legal Provisions and are provided without warranty as 61 described in the Simplified BSD License. 63 Table of Contents 65 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 66 2. Usage Scenarios . . . . . . . . . . . . . . . . . . . . . . . 2 67 3. PMIPv6 Extensions . . . . . . . . . . . . . . . . . . . . . . 3 68 4. Session Connectivity . . . . . . . . . . . . . . . . . . . . 5 69 5. Message Format . . . . . . . . . . . . . . . . . . . . . . . 6 70 6. Other Issues . . . . . . . . . . . . . . . . . . . . . . . . 6 71 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 72 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 73 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 74 9.1. Normative References . . . . . . . . . . . . . . . . . . 7 75 9.2. Informative References . . . . . . . . . . . . . . . . . 8 76 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 78 1. Introduction 80 Network managers currently prefer Provider Independent (PI) 81 addressing for IPv6 to attempt to minimize the need for future 82 possible renumbering. However, a widespread use of PI addresses may 83 cause Border Gateway Protocol (BGP) scaling problems [RFC7010]. It 84 is thus desirable to develop tools and practices that make IPv6 85 renumbering a simpler process to reduce demand for IPv6 PI space 86 [RFC6879]. In this document, we aim to solve the HNP renumbering 87 problem when the HNP in PMIPv6 [RFC5213] is not the type of PI. 89 2. Usage Scenarios 91 There are a number of reasons why the HNP renumbering support in 92 PMIPv6 is useful and some scenarios are identified below: 94 o Scenario 1: the HNP set used by a PMIPv6 service provider is 95 assigned by a different Internet Service Provider (ISP), and then 96 the HNP renumbering may happen if the PMIPv6 service provider 97 switches to a different ISP. 99 o Scenario 2: multiple Local Mobility Anchors (LMAs) may be deployed 100 by the same PMIPv6 service provider, and then each LMA may serve 101 for a specific HNP set. In this case, the HNP of an MN may change 102 if the current serving LMA switches to another LMA but without 103 inheriting the assigned HNP set [RFC6463]. 105 o Scenario 3: the PMIPv6 HNP renumbering may be caused by the re- 106 building of the network architecture as the companies split, 107 merge, grow, relocate, or reorganize. For example, the PMIPv6 108 service provider may reorganize its network topology. 110 In the scenario 1, we assume that only the HNP is renumbered while 111 the serving LMA remains unchanged and this is the basic scenario 112 considered in this document. In the scenario 2 and scenario 3, more 113 complex results may be caused, for example, the HNP renumbering may 114 happen due to the switchover of a serving LMA. 116 In the Mobile IPv6 (MIPv6) protocol, when a home network prefix 117 changes, the Home Agent (HA) will actively notify the new prefix to 118 its MN and then the renumbering of the Home Network Address (HoA) can 119 be well supported [RFC6275]. In the basic PMIPv6, the PMIPv6 binding 120 is triggered by a Mobile Access Gateway (MAG), which detects the 121 attachment of the MN. A scheme is also needed for the LMA to 122 immediately initiate the PMIPv6 binding state refreshment during the 123 HNP renumbering process. Although this issue is also mentioned in 124 Section 6.12 of [RFC5213], the related solution has not been 125 specified. 127 3. PMIPv6 Extensions 129 When the HNP renumbering happens in PMIPv6, the LMA has to notify a 130 new HNP to an MAG and then the MAG has to announce the new HNP to the 131 attached MN accordingly. Also, the LMA and the MAG must update the 132 routing states for the HNP and the related addresses. To support 133 this procedure, [RFC7077] can be adopted which specifies an 134 asynchronous update from the LMA to the MAG about specific session 135 parameters. This document considers the following two cases: 137 (1) HNP is renumbered under the same LMA 139 In this case, the LMA remains unchanged as in the scenario 1 and 140 scenario 3. The operation steps are shown in Figure 1. 142 +-----+ +-----+ +-----+ 143 | MN | | MAG | | LMA | 144 +-----+ +-----+ +-----+ 145 | | | 146 | | Allocate new HNP 147 | | | 148 | |<------------- UPN ---| 149 | | | 150 | | | 151 | | | 152 |<-----RA/DHCP --------| | 153 | | | 154 Address configuration | | 155 | | | 156 | Update binding&routing states | 157 | | | 158 | |--- UPA ------------->| 159 | | | 160 | | Update binding&routing states 161 | | | 163 Figure 1: Signaling call flow of the HNP renumbering 165 o When a PMIPv6 service provider renumbers the HNP set under the 166 same LMA, the serving LMA will initiate the HNP renumbering 167 operation. The LMA allocates a new HNP for the related MN. 169 o The LMA sends the Update Notification (UPN) message to the MAG to 170 update the HNP information. If the Dynamic Host Configuration 171 Protocol (DHCP) is used to allocate the address, the new HNP 172 should be also notified to the DHCP infrastructure. 174 o Once the MAG receives this UPN message, it recognizes that the 175 related MN has the new HNP. Then the MAG should notify the MN 176 about the new HNP with a Router Advertisement (RA) message or 177 allocate a new address within the new HNP through a DHCP 178 procedure. 180 o After the MN obtains the HNP information through the RA message, 181 it deletes the old HoA and configures a new HoA with the newly 182 allocated HNP. 184 o When the new HNP is announced or the new address is configured to 185 the MN successfully, the MAG updates the related binding and 186 routing states. Then the MAG sends back the Update Notification 187 Acknowledgement (UPA) message to the LMA for the notification of 188 successful update of the HNP, related binding state, and routing 189 state. Then the LMA updates the routing and binding information 190 corresponding to the MN to replace the old HNP with the new one. 192 (2) HNP renumbering caused by the LMA switchover 194 Since the HNP is assigned by the LMA, the HNP renumbering may be 195 caused by the LMA switchover, as in the scenario 2 and scenario 3. 197 The information of LMA is the basic configuration information of MAG. 198 When the LMA changes, the related profile should be updated by the 199 service provider. In this way, the MAG initiates the registration to 200 the new LMA as specified in [RFC5213]. When the HNP renumbering is 201 caused in this case, the new HNP information is sent by the LMA 202 during the new binding procedure. Accordingly, the MAG withdraws the 203 old HNP of the MN and announces the new HNP to the MN as like the 204 case of the HNP is renumbered under the same LMA. 206 4. Session Connectivity 208 The HNP renumbering may cause the disconnection of the ongoing 209 communications of the MN. Basically, there are two modes to manage 210 the session connectivity during the HNP renumbering. 212 (1) Soft-mode 214 The LMA will temporarily maintain the state of the old HNP during the 215 HNP renumbering (after the UPA reception) in order to redirect the 216 packets to the MN before the MN reconnects the ongoing session and 217 notifies its new HoA to the Correspondent Node (CN). This mode is 218 aiming to reduce the packet loss during the HNP renumbering but the 219 binding state corresponding to the old HNP should be marked for 220 example as transient binding [RFC6058]. This temporary binding 221 should only be used for the downwards packet transmission and the LMA 222 should stop broadcasting the routing information about the old HNP if 223 the old HNP is no longer anchored at this LMA. 225 (2) Hard-mode 227 If the HNP renumbering happens with the switchover of the LMA, the 228 hard-mode is recommended to keep the protocol simple. In this mode, 229 the LMA deletes the binding state of the old HNP after it receives 230 the UPA message from the MAG and the LMA silently discards the 231 packets destined to the old HNP. 233 5. Message Format 235 (1) UPN message 237 In the UPN message sent from the LMA to the MAG, the notification 238 reason is set to 2 (UPDATE-SESSION-PARAMETERS). Besides, the HNP 239 Option [RFC5213] containing the new HNP and the Mobile Node 240 Identifier Option [RFC4283] carrying identifier of MN are contained 241 as Mobility Options of UPN. The order of HNP Option and Mobile Node 242 Identifier Option in the UPN message is not mandated in this draft. 244 (2) UPA message 246 The MAG sends this message in order to acknowledge that it has 247 received an UPN message with the (A) flag set and to indicate the 248 status after processing the message. When the MAG did not 249 successfully renumber the HNP which is required in the UPN message, 250 the Status Code of 128 is set in the UPA message and the following 251 operation of LMA is PMIPv6 service provider specific. 253 (3) RA Message 255 When the RA message is used by the MAG to advise the new HNP, two 256 Prefix Information Options are contained in the RA message [RFC4861]. 257 In the first Prefix Information Option, the old HNP is carried but 258 both the related Valid Lifetime and Preferred Lifetime are set to 0. 259 In the second Prefix Information Option, the new HNP is carried with 260 the Valid Lifetime and Preferred Lifetime set to larger than 0. 262 (4) DHCP Message 264 When the DHCP is used in PMIPv6 to configure the addresses for the 265 MN, new IPv6 address(es) (e.g., HoA) will be generated based on the 266 new HNP and the related DHCP procedure is also triggered by the 267 reception of UPN message [RFC3315]. 269 6. Other Issues 271 In order to maintain the reachability of the MN, the Domain Name 272 System (DNS) resource record corresponding to this MN may need to be 273 updated when the HNP of MN changes [RFC3007]. However, this is 274 beyond the scope of this document. 276 The LMA must assign only an authorized HNP for the MN. 278 7. Security Considerations 280 The protection of UPN and UPA messages in this document follows 281 [RFC5213] and [RFC7077]. This extension thus causes no further 282 security problems for protecting of the messages. 284 8. IANA Considerations 286 This document presents no IANA considerations. 288 9. References 290 9.1. Normative References 292 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 293 Requirement Levels", BCP 14, RFC 2119, 294 DOI 10.17487/RFC2119, March 1997, 295 . 297 [RFC3007] Wellington, B., "Secure Domain Name System (DNS) Dynamic 298 Update", RFC 3007, DOI 10.17487/RFC3007, November 2000, 299 . 301 [RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, 302 C., and M. Carney, "Dynamic Host Configuration Protocol 303 for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July 304 2003, . 306 [RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K. 307 Chowdhury, "Mobile Node Identifier Option for Mobile IPv6 308 (MIPv6)", RFC 4283, DOI 10.17487/RFC4283, November 2005, 309 . 311 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 312 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 313 DOI 10.17487/RFC4861, September 2007, 314 . 316 [RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V., 317 Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", 318 RFC 5213, DOI 10.17487/RFC5213, August 2008, 319 . 321 [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility 322 Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 323 2011, . 325 [RFC6463] Korhonen, J., Ed., Gundavelli, S., Yokota, H., and X. Cui, 326 "Runtime Local Mobility Anchor (LMA) Assignment Support 327 for Proxy Mobile IPv6", RFC 6463, DOI 10.17487/RFC6463, 328 February 2012, . 330 [RFC7077] Krishnan, S., Gundavelli, S., Liebsch, M., Yokota, H., and 331 J. Korhonen, "Update Notifications for Proxy Mobile IPv6", 332 RFC 7077, DOI 10.17487/RFC7077, November 2013, 333 . 335 9.2. Informative References 337 [RFC6058] Liebsch, M., Ed., Muhanna, A., and O. Blume, "Transient 338 Binding for Proxy Mobile IPv6", RFC 6058, 339 DOI 10.17487/RFC6058, March 2011, 340 . 342 [RFC6879] Jiang, S., Liu, B., and B. Carpenter, "IPv6 Enterprise 343 Network Renumbering Scenarios, Considerations, and 344 Methods", RFC 6879, DOI 10.17487/RFC6879, February 2013, 345 . 347 [RFC7010] Liu, B., Jiang, S., Carpenter, B., Venaas, S., and W. 348 George, "IPv6 Site Renumbering Gap Analysis", RFC 7010, 349 DOI 10.17487/RFC7010, September 2013, 350 . 352 Authors' Addresses 354 Zhiwei Yan 355 CNNIC 356 No.4 South 4th Street, Zhongguancun 357 Beijing 100190 358 China 360 EMail: yan@cnnic.cn 362 Jong-Hyouk Lee 363 Sangmyung University 364 31, Sangmyeongdae-gil, Dongnam-gu 365 Cheonan 31066 366 Republic of Korea 368 EMail: jonghyouk@smu.ac.kr 369 Xiaodong Lee 370 CNNIC 371 No.4 South 4th Street, Zhongguancun 372 Beijing 100190 373 China 375 EMail: xl@cnnic.cn