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'IANAEnterprise' ** Obsolete normative reference: RFC 2460 (Obsoleted by RFC 8200) ** Obsolete normative reference: RFC 3315 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 3484 (Obsoleted by RFC 6724) ** Obsolete normative reference: RFC 3633 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 3775 (Obsoleted by RFC 6275) ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) -- Obsolete informational reference (is this intentional?): RFC 2629 (Obsoleted by RFC 7749) Summary: 6 errors (**), 0 flaws (~~), 4 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Internet Engineering Task Force S. Bhandari 3 Internet-Draft G. Halwasia 4 Intended status: Standards Track S. Bandi 5 Expires: January 17, 2013 S. Gundavelli 6 Cisco Systems 7 H. Deng 8 China Mobile 9 L. Thiebaut 10 Alcatel-Lucent 11 July 16, 2012 13 DHCPv6 class based prefix 14 draft-bhandari-dhc-class-based-prefix-02 16 Abstract 18 DHCPv6 defines class based allocation of IA_NA and IA_TA IPv6 19 addresses. This document extends DHCPv6 prefix delegation with class 20 based prefix allocation. It defines a new usage class option to 21 classify a prefix. It defines the behavior of a DHCPv6 client 22 requesting a prefix to include the class of the prefix to be 23 allocated and the DHCPv6 server behavior to select and offer a prefix 24 from a given class. It discusses how IA_NA can be requested and 25 assigned from a specific usage class. 27 Status of this Memo 29 This Internet-Draft is submitted in full conformance with the 30 provisions of BCP 78 and BCP 79. 32 Internet-Drafts are working documents of the Internet Engineering 33 Task Force (IETF). Note that other groups may also distribute 34 working documents as Internet-Drafts. The list of current Internet- 35 Drafts is at http://datatracker.ietf.org/drafts/current/. 37 Internet-Drafts are draft documents valid for a maximum of six months 38 and may be updated, replaced, or obsoleted by other documents at any 39 time. It is inappropriate to use Internet-Drafts as reference 40 material or to cite them other than as "work in progress." 42 This Internet-Draft will expire on January 17, 2013. 44 Copyright Notice 46 Copyright (c) 2012 IETF Trust and the persons identified as the 47 document authors. All rights reserved. 49 This document is subject to BCP 78 and the IETF Trust's Legal 50 Provisions Relating to IETF Documents 51 (http://trustee.ietf.org/license-info) in effect on the date of 52 publication of this document. Please review these documents 53 carefully, as they describe your rights and restrictions with respect 54 to this document. Code Components extracted from this document must 55 include Simplified BSD License text as described in Section 4.e of 56 the Trust Legal Provisions and are provided without warranty as 57 described in the Simplified BSD License. 59 Table of Contents 61 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 62 1.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 3 63 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 64 1.3. Requirements Language . . . . . . . . . . . . . . . . . . 4 65 2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 66 2.1. Usage Class Option . . . . . . . . . . . . . . . . . . . . 4 67 2.2. Consideration for different DHCPv6 entities . . . . . . . 6 68 2.2.1. Requesting Router Behavior . . . . . . . . . . . . . . 6 69 2.2.2. Delegating Router Behavior . . . . . . . . . . . . . . 7 70 2.2.3. DHCPv6 Client Behavior for IA_NA allocation . . . . . 7 71 2.3. Usage . . . . . . . . . . . . . . . . . . . . . . . . . . 8 72 2.3.1. OPTION_USAGE_CLASS Values . . . . . . . . . . . . . . 8 73 2.3.2. Class based prefix and IA_NA allocation . . . . . . . 8 74 2.3.3. Class based prefix and IA_PD allocation . . . . . . . 9 75 2.3.4. Class based prefix and SLAAC . . . . . . . . . . . . . 9 76 2.3.5. Class based prefix and applications . . . . . . . . . 9 77 3. Example Application . . . . . . . . . . . . . . . . . . . . . 9 78 3.1. Class based prefix delegation . . . . . . . . . . . . . . 12 79 3.2. IPv6 address assignment from class based prefix . . . . . 12 80 4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13 81 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 82 5.1. OPTION_USAGE_CLASS values . . . . . . . . . . . . . . . . 13 83 6. Security Considerations . . . . . . . . . . . . . . . . . . . 14 84 7. Change History (to be removed prior to publication as an 85 RFC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 86 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14 87 8.1. Normative References . . . . . . . . . . . . . . . . . . . 14 88 8.2. Informative References . . . . . . . . . . . . . . . . . . 15 89 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 91 1. Introduction 93 DHCPv6 based prefix delegation as defined in [RFC3633] is a mechanism 94 for the delegation of IPv6 prefixes using DHCPv6 options. Through 95 these options, a delegating router can delegate prefixes to 96 authorized requesting routers. If the requesting router has to 97 function as a DHCPv6 server there needs to be additional information 98 in the delegated prefix that helps the requesting router to select 99 the address allocation for the DHCPv6 client it serves, from one of 100 the available delegated prefixes. 102 One way to select an address or longer prefix (from a delegated 103 prefix) to be allocated by a requesting router playing the role of a 104 DHCPv6 server is by introducing additional options in IA_PD to be 105 matched with options for address selection in the DHCPv6 SOLICIT 106 message. [RFC3315] defines the OPTION_USER_CLASS option which is 107 used for selecting address for assignment. This document introduces 108 OPTION_USAGE_CLASS option in IA_PD option for the purpose of 109 selecting a prefix for further delegation either via IA_NA or IA_PD 110 DHCPv6 request. It defines the behavior of the DHCPv6 server, the 111 DHCPv6 prefix requesting router and the DHCPv6 client to use this 112 option. 114 In IPv6 a network interface can acquire multiple addresses from the 115 same scope. In this case application need to have additional 116 information about the prefix configured on the interface for source 117 address selection. Since the network address can be configured via 118 DHCPv6 as defined in [RFC3315] or via Stateless Address 119 Autoconfiguration (SLAAC) as defined in [RFC4862], additional 120 information of a prefix can be provided via DHCPv6 or via IPv6 Router 121 Advertisement (RA). 123 1.1. Motivation 125 In this section motivation for class based prefix delegation that 126 qualifies the delegated prefix with additional class information is 127 described in the context of mobile networks. The class information 128 attached to a delegated prefix helps to distinguish property of a 129 delegated IPv6 prefix and selection of the prefix by different 130 applications using it. 132 In the mobile network architecture, there is a mobile router which 133 functions as a IP network gateway and provides IP connectivity to 134 mobile nodes. Mobile router can be the requesting router requesting 135 delegated IPv6 prefix using DHCPv6. Mobile router can assume the 136 role of DHCPv6 server for mobile nodes(DHCPv6 clients) attached to 137 it. A mobile node in mobile network architecture can be associated 138 with multiple IPv6 prefixes belonging to different domains for e.g. 140 home address prefix, care of address prefix as specified in 141 [RFC3775]. 143 The delegated prefixes when seen from the mobile router perspective 144 appear to be like any other prefix, but each prefixes have different 145 properties referred to as "Prefix Color" in the mobile networks. 146 Some delegated prefixes may be topologically local and some may be 147 remote prefixes anchored on a global anchor, but available to the 148 local anchor by means of tunnel setup in the network between the 149 local and global anchor. Some may be local with low latency 150 characteristics suitable for voice call break-out, some may have 151 global mobility support. So, the prefixes have different properties 152 and it is required for the application using the prefix to learn 153 about this property in order to use it intelligently. There is 154 currently no semantics in DHCPv6 prefix delegation that can carry 155 this information to specify properties of a delegated prefix. In 156 this scenario, the mobile router is unable to further delegate a 157 longer prefix intelligently based on properties of the prefix learnt. 159 1.2. Terminology 161 This document uses the terminology defined in [RFC2460], [RFC3315] 162 and [RFC3633]. 164 1.3. Requirements Language 166 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 167 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 168 document are to be interpreted as described in RFC 2119 [RFC2119]. 170 2. Overview 172 This section defines usage class option in IA_PD and IA_NA to aid 173 class based prefix delegation and address assignment. This section 174 defines the behavior of the delegating router, the requesting router 175 and the DHCPv6 client. 177 2.1. Usage Class Option 178 The format of the DHCPv6 usage class option is shown below. 179 0 1 2 3 180 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 1 181 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 182 | OPTION_USAGE_CLASS | option-length(2) | 183 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 184 | Class | ~ 185 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- ~ 186 ~ Vendor Class Data (Optional,variable length) ~ 187 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 option-code: OPTION_USAGE_CLASS (TBD) 190 option-length: 2 + Length of Vendor class information 191 if present 192 Class: 16 bit numeric value maintained as 193 OPTION_USAGE_CLASS enumeration in 194 IANA registered namespace 195 Vendor Class Data: If the value of Class (3) indicates it is 196 vendor specified additional vendor 197 specified data of variable length will be 198 attached in the form specified below: 199 0 1 2 3 200 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 1 201 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 202 | OPTION_USAGE_CLASS | option-length(2) | 203 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 204 | Class | Enterprise ID | 205 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 206 | Enterprise ID(4) | Vendor Class length(2) | 207 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 208 ~ Vendor Class Data (Variable length) ~ 209 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 211 Enterprise ID: The vendor's 32-bit Enterprise Number as 212 registered with IANA [IANAEnterprise] 213 Vendor Class Length: 2, length of vendor class data that follows 214 Vendor Class Data: Binary data as defined by the vendor. 215 For e.g. 3gpp can specify this data to be 216 Application providers network domain string 218 The class values are maintained in OPTION_USAGE_CLASS values 219 enumeration explained in Section Section 2.3.1. 221 2.2. Consideration for different DHCPv6 entities 223 The model of operation of communicating prefixes to be used by a 224 DHCPv6 server is as follows. A requesting router requests prefix(es) 225 from the delegating router, as described in Section 2.2.1. A 226 delegating router is provided IPv6 prefixes to be delegated to the 227 requesting router. Examples of ways in which the delegating router 228 is provided these prefixes are: 230 o Configuration 232 o Prefix delegated via a DHCPv6 request to another DHCPv6 server 234 o Using a Authentication Authorization Accounting (AAA) protocol 235 like RADIUS [RFC2865] 237 The delegating router chooses prefix(es) for delegation, and responds 238 with prefix(es) to the requesting router along with additional 239 options in the allocated prefix as described in Section 2.2.2. The 240 requesting router is then responsible for the delegated prefix(es) 241 after the DHCPv6 REQUEST message exchange. For example, the 242 requesting router may create DHCPv6 server configuration pools from 243 the delegated prefix, and function as a DHCPv6 Server. When the 244 requesting router then receives a DHCPv6 IA_NA requests it can select 245 the address to be allocated based on the OPTION_USER_CLASS or 246 OPTION_USAGE_CLASS options received in IA_NA request or any of the 247 other methods as described in Section 2.3.1. 249 2.2.1. Requesting Router Behavior 251 DHCPv6 requesting router can request for prefixes in the following 252 ways: 254 o In the SOLICIT message within the IA_PD Prefix option, it MAY 255 include OPTION_USAGE_CLASS requesting prefix delegation for the 256 specific class indicated in the OPTION_USAGE_CLASS option. It can 257 include multiple IA_PD Prefix options to indicate it's preference 258 for more than one usage class. 260 o In the SOLICIT message include an OPTION_ORO option with the 261 OPTION_USAGE_CLASS option code to request prefixes from all the 262 classes that the DHCPv6 server can provide to this requesting 263 Router. 265 The requesting router parses the OPTION_USAGE_CLASS option in 266 theOPTION_IAPREFIX option area of the corresponding IA_PD Prefix 267 option in the ADVERTISE message. The Requesting router MUST then 268 include all or subset of the received class based prefix(es) in the 269 REQUEST message so that it will be responsible for the prefixes 270 selected. 272 2.2.2. Delegating Router Behavior 274 If the Delegating router supports class based prefix allocation by 275 supporting the OPTION_USAGE_CLASS option and it is configured to 276 assign prefixes from different classes, it selects prefixes for class 277 based prefix allocation in the following way: 279 o If requesting router includes OPTION_USAGE_CLASS within the IA_PD 280 Prefix option, it selects prefixes to be offered from that 281 specific class. 283 o If requesting router includes OPTION_USAGE_CLASS within 284 OPTION_ORO, then based on its configuration and policy it MAY 285 offer prefixes from multiple classes available. 287 The delegating router responds with an ADVERTISE message after 288 populating the IP_PD option with prefixes from different usage 289 classes. Along with including the IA_PD prefix options in the IA_PD 290 option, it also includes the OPTION_USAGE_CLASS option in the 291 OPTION_IAPREFIX option area of the corresponding IA_PD prefix option. 293 If neither the OPTION_ORO nor the IA_PD option in the SOLICIT message 294 include the OPTION_USAGE_CLASS option, then the delegating router MAY 295 allocate the prefix as specified in [RFC3633] without including the 296 class option in the IA_PD prefix option in the response. 298 If OPTION_ORO option in the Solicit message includes the 299 OPTION_USAGE_CLASS option code but the delegating router does not 300 support the solution described in this specification, then the 301 delegating router acts as specified in [RFC3633]. The requesting 302 router MUST in this case also fall back to the behavior specified in 303 [RFC3633]. 305 If both delegating and requesting routers support class-based prefix 306 allocation, but the delegating router cannot offer prefixes for any 307 other reason, it MUST respond to requesting router with appropriate 308 status code as specified in [RFC3633]. For e.g., if no prefixes are 309 available in the specified class then the delegating router MUST 310 include the status code NoPrefixAvail in the response message. 312 2.2.3. DHCPv6 Client Behavior for IA_NA allocation 314 DHCPv6 client MAY request for an IA_NA address allocation from a 315 specific usage class in the following way: 317 o In the SOLICIT message within the IA_NA option, it MAY include the 318 OPTION_USAGE_CLASS requesting address to be allocated from a 319 specific usage class indicated in that option. 321 The DHCPv6 server parses OPTION_USAGE_CLASS option received and 322 includes it in option area of corresponding OPTION_IA_NA in ADVERTISE 323 message. 325 2.3. Usage 327 Class based prefix delegation can be used by the requesting router to 328 configure itself as a DHCPv6 server to serve its DHCPv6 clients. It 329 can allocate longer prefixes from a delegated shorter prefix it 330 received, for serving IA_NA and IA_PD requests. 332 2.3.1. OPTION_USAGE_CLASS Values 334 Following values will be allocated from the IANA maintained 335 OPTION_USAGE_CLASS registry: 337 o global-anchor(1) - Prefix is globally anchored and hence would 338 allow mobility. 340 o local-breakout(2) - Prefix is managed in a local-breakout domain 341 and hence has limited mobility. 343 o Vendor-specfied-class(3) - Prefix class is specified by the 344 vendor, Vendor class data in the option that follows will provide 345 more information. 347 New values of OPTION_USAGE_CLASS can be assigned and registered with 348 IANA as per policy detailed in section Section 5.1. 350 2.3.2. Class based prefix and IA_NA allocation 352 The requesting router can use the delegated prefix(es) from different 353 classes (for example "video", "guest", "voice" etc), for assigning 354 the IPv6 addresses to the end hosts through DHCPv6 IA_NA based on a 355 preconfigured mapping with OPTION_USAGE_CLASS option, the following 356 conditions MAY be observed: 358 o It MAY have a pre-configured mapping between the usage class and 359 OPTION_USER_CLASS option received in IA_NA. 361 o It MAY match the OPTION_USAGE_CLASS if the IA_NA request received 362 contains OPTION_USAGE_CLASS. 364 o It MAY have a pre-configured mapping between the usage class and 365 the client DUID received in DHCPv6 message. 367 o It MAY have a pre-configured mapping between the usage class and 368 its network interface on which the IA_NA request was received. 370 The requesting router playing the role of a DHCPv6 server can 371 ADVERTISE IA_NA from a class of prefix(es) thus selected. 373 2.3.3. Class based prefix and IA_PD allocation 375 If the requesting router, receives prefix(es) for different classes 376 (for example "video", "guest", "voice" etc), it can use these 377 prefix(es) for assigning the longer IPv6 prefixes to requesting 378 routers it serves through DHCPv6 IA_PD by assuming the role of 379 delegating router, its behavior is explained in Section 2.2.2. 381 2.3.4. Class based prefix and SLAAC 383 DHCPv6 IA_NA and IPv6 Stateless Address Autoconfiguration (SLAAC as 384 defined in [RFC4862]) are two ways by IPv6 addresses can be 385 dynamically assigned to end hosts. Making SLAAC class aware is 386 outside the scope of this document, it is specified in 387 [I-D.korhonen-dmm-prefix-properties]. 389 2.3.5. Class based prefix and applications 391 Applications within a host can do source address selection based on 392 the class of the prefix learnt in OPTION_USAGE_CLASS using rules 393 defined in [RFC3484]. 395 3. Example Application 397 The following sub-sections provide examples of class based prefix 398 delegation and how it is used in a mobile network. Each of the 399 examples will refer to the below network: 401 The example network consists of : 403 Mobile Gateway It is network entity anchoring IP traffic in the 404 mobile core network. This entity allocates an IP address which is 405 topologically valid in the mobile network and may act as a mobility 406 anchor if handover between mobile and Wi-Fi is supported. 408 Mobile Nodes (MN) A host or router that changes its point of 409 attachment from one network or subnetwork to another. A mobile node 410 may change its location without changing its IP address; it may 411 continue to communicate with other Internet nodes at any location 412 using its (constant) IP address, assuming link-layer connectivity to 413 a point of attachment is available. 415 Access Point (AP) A wireless access point, identified by a MAC 416 address, providing service to the wired network for wireless nodes. 418 Access Router (AR) An IP router residing in an access network and 419 connected to one or more Acess Point(AP)s. An AR offers IP 420 connectivity to MNs. 422 WLAN controller (WLC) The entity that provides the centralized 423 forwarding, routing function for the user traffic. 425 Example mobile network 426 _----_ _----_ _----_ 427 _( )_ _( )_ _( )_ 428 (Operator-1) (Operator-2) (Operator-3) 429 (_ _) (_ _) (_ _) 430 -+-- -+-- '-+--' 431 +--------+ +--------+ +--------+ 432 | Mobile | | Mobile | | Mobile | 433 |gateway | |gateway | |gateway | 434 +--------+ +--------+ +--------+ 435 | | | 436 +-------------. | .-------------+ 437 | | | 438 | | | 439 | | |P1:"global-anchor"(1) 440 | | | 441 +--------+ _----_ 442 +---+ | |P2:"local-breakout"(2)_( )_ 443 |AAA|. . . . . . . | Access |---------------------( Internet ) 444 +---+ | Aggreg |-----------+ (_ _) 445 | Gateway| P3:"guest"| '----' 446 +--------+ | 447 | | +----- Guest Access 448 | | Network 449 | +-------------+ 450 | | 451 | +-----+ 452 | | AR | 453 +-----+ +-----+ 454 | WLC | * ---------* 455 | | ( LAN ) 456 +-----+ * ---------* 457 / \ / \ 458 +----+ +----+ +----+ +----+ 459 |WiFi| |WiFi| |WiFi| |WiFi| 460 | AP | | AP | | AP | | AP | 461 +----+ +----+ +----+ +----+ 462 . . 463 / \ / \ 464 MN1 MN2 MN3 MN4(guest) 466 Figure 1 468 3.1. Class based prefix delegation 470 The Access Aggregation Gateway requests for Prefix delegation from 471 Mobile gateway and associates the prefix received with usage class 472 "global-anchor"(1). The Access Aggregation Gateway is preconfigured 473 to provide prefixes from the following classes: "global-anchor" (1), 474 "local-breakout"(2), "guest"(x). It has a preconfigured policy to 475 advertise prefixes to requesting routers and mobile nodes based on 476 the service class supported by the service provider for the 477 requesting device. In the example mobile network, the Access 478 Router(AR) requests class based prefix allocation by sending a DHCPv6 479 SOLICIT message and include OPTION_USAGE_CLASS in the OPTION_ORO. 481 The Access Router (AR) receives an advertise with following prefixes 482 in the IA_PD option: 484 1. P1: IA_PD Prefix option with a prefix 3001::1::/64 containing 485 OPTION_USAGE_CLASS set to "global-anchor"(1) 487 2. P2: IA_PD Prefix option with a prefix 3001::2::/64 containing 488 OPTION_USAGE_CLASS set to "local-breakout"(2) 490 3. P3: IA_PD Prefix option with a prefix 3001::3::/64 containing 491 OPTION_USAGE_CLASS set to "guest"(x) 493 It sends a REQUEST message with all of above prefixes and receives a 494 REPLY message with prefixes allocated for each of the requested 495 class. 497 3.2. IPv6 address assignment from class based prefix 499 When the Access Router(AR) receives a DHCPv6 SOLICIT requesting IA_NA 500 from the mobile node that has mobility service enabled, it offers an 501 IPv6 address from the usage class "global-anchor"(1). For MN3 it 502 advertises 3001::1::1 as the IPv6 address in OPTION_IAADDR in 503 response to the IA_NA request. 505 The Mobile Node(MN4) Figure 1 sends a DHCPv6 SOLICIT message 506 requesting IA_NA address assignment with OPTION_USER_CLASS option 507 containing the value "guest" towards the CPE. The Access Router(AR) 508 assumes the role of the DHCPv6 server and sends an ADVERTISE to the 509 MN with OPTION_IA_NA containing an IPv6 address in OPTION_IAADDR from 510 the "guest" usage class. The IPv6 address in the OPTION_IAADDR is 511 set to 3001::3::1. The "guest" class can also be distinguished based 512 on a preconfigured interface or SSID advertised for MNs connecting to 513 it. 515 When the Access Aggregation Gateway receives a DHCPv6 SOLICIT 516 requesting IA_NA from MNs through WLC and it has a preconfigured 517 profile to provide both local-breakout internet access and global- 518 anchor, it offers an IPv6 address from the usage class "local- 519 breakout" (2) and "global-anchor"(1). For MN1 it advertises 520 3001::2::1 and 3001::1::2 as the IPv6 address in OPTION_IAADDR in 521 response to the IA_NA request. Applications within MN1 can choose to 522 use the appropriate prefix based on the mobility enabled or local- 523 breakout property attached to the prefix based on source address 524 selection policy. 526 4. Acknowledgements 528 The authors would like to acknowledge review and guidance received 529 from Frank Brockners, Wojciech Dec, Richard Johnson, Erik Nordmark, 530 Hemant Singh, Mark Townsley, Ole Troan, Bernie Volz 532 5. IANA Considerations 534 IANA is requested to assign an option code to OPTION_USAGE_CLASS from 535 the "DHCPv6 and DHCPv6 options" registry (http://www.iana.org/ 536 assignments/dhcpv6-parameters/dhcpv6-parameters.xml). 538 5.1. OPTION_USAGE_CLASS values 540 IANA is requested to reserve and maintain registry of 541 OPTION_USAGE_CLASS values and manage allocation of values in the 542 following way as per as per policy defined in [RFC5226]: 544 1. Values 1 to 8191 ( 0x0001 - 0x1FFF) - IETF assigned class with 545 IETF consensus, RFC Required policy 547 2. Values 8192 to 16368 (0x2000 - 0x3ff0) - Vendor defined class 548 assigned on a First Come First Served allocation policy 550 3. Values 16369 to 16383 (0x3ff1 - 0x3fff) - Experimental usage 551 reserved for Private Use 553 Following values will be allocated from this registry as explained in 554 section Section 2.3.1: 556 o global-anchor(1) - Prefix is globally anchored and hence would 557 allow mobility. 559 o local-breakout(2) - Prefix is managed in a local-breakout domain 560 and hence has limited mobility. 562 o Vendor-specfied-class(3) - Prefix class is vendor specified. 564 6. Security Considerations 566 Security issues related to DHCPv6 which are described in section 23 567 of [RFC3315] and [RFC3633] apply for scenarios mentioned in this 568 draft as well. 570 7. Change History (to be removed prior to publication as an RFC) 572 Changes from -00 to -01 574 a. Modified motivation section to focus on mobile networks 576 b. Modified example with a mobile network and class based prefix 577 delegation in it 579 Changes from -00 to -02 581 a. Modified option format to be enumerated values 583 b. Added IANA section to request managing of registry for the 584 enumerated values 586 c. Added initial values for the class 588 d. Added section for applications to select address with a specific 589 property 591 8. References 593 8.1. Normative References 595 [I-D.korhonen-dmm-prefix-properties] 596 Korhonen, J., Patil, B., Gundavelli, S., Seite, P., and D. 597 Liu, "IPv6 Prefix Mobility Management Properties", 598 draft-korhonen-dmm-prefix-properties-02 (work in 599 progress), July 2012. 601 [IANAEnterprise] 602 IANA, "Private Enterprise Numbers, 603 http://www.iana.org/assignments/enterprise-numbers". 605 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 606 Requirement Levels", BCP 14, RFC 2119, March 1997. 608 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 609 (IPv6) Specification", RFC 2460, December 1998. 611 [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, 612 "Remote Authentication Dial In User Service (RADIUS)", 613 RFC 2865, June 2000. 615 [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., 616 and M. Carney, "Dynamic Host Configuration Protocol for 617 IPv6 (DHCPv6)", RFC 3315, July 2003. 619 [RFC3484] Draves, R., "Default Address Selection for Internet 620 Protocol version 6 (IPv6)", RFC 3484, February 2003. 622 [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic 623 Host Configuration Protocol (DHCP) version 6", RFC 3633, 624 December 2003. 626 [RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support 627 in IPv6", RFC 3775, June 2004. 629 [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless 630 Address Autoconfiguration", RFC 4862, September 2007. 632 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 633 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 634 May 2008. 636 8.2. Informative References 638 [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, 639 June 1999. 641 [RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC 642 Text on Security Considerations", BCP 72, RFC 3552, 643 July 2003. 645 Authors' Addresses 647 Shwetha Bhandari 648 Cisco Systems 649 Cessna Business Park, Sarjapura Marathalli Outer Ring Road 650 Bangalore, KARNATAKA 560 087 651 India 653 Phone: 654 Email: shwethab@cisco.com 656 Gaurav Halwasia 657 Cisco Systems 658 Cessna Business Park, Sarjapura Marathalli Outer Ring Road 659 Bangalore, KARNATAKA 560 087 660 India 662 Phone: +91 80 4426 1321 663 Email: ghalwasi@cisco.com 665 Sindhura Bandi 666 Cisco Systems 667 Cessna Business Park, Sarjapura Marathalli Outer Ring Road 668 Bangalore, KARNATAKA 560 087 669 India 671 Phone: +91 80 4426 2347 672 Email: sinb@cisco.com 674 Sri Gundavelli 675 Cisco Systems 676 170 West Tasman Drive 677 San Jose, CA 95134 678 USA 680 Email: sgundave@cisco.com 681 Hui Deng 682 China Mobile 683 53A, Xibianmennei Ave., Xuanwu District 684 Beijing 100053 685 China 687 Email: denghui02@gmail.com 689 Laurent Thiebaut 690 Alcatel-Lucent 691 France 693 Email: laurent.thiebaut@alcatel-lucent.com