idnits 2.17.1 draft-ietf-dmm-ondemand-mobility-15.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (July 26, 2018) is 2101 days in the past. Is this intentional? -- Found something which looks like a code comment -- if you have code sections in the document, please surround them with '' and '' lines. Checking references for intended status: Informational ---------------------------------------------------------------------------- -- Obsolete informational reference (is this intentional?): RFC 6824 (Obsoleted by RFC 8684) Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 DMM Working Group A. Yegin 3 Internet-Draft Actility 4 Intended status: Informational D. Moses 5 Expires: January 27, 2019 Intel 6 K. Kweon 7 J. Lee 8 J. Park 9 Samsung 10 S. Jeon 11 Sungkyunkwan University 12 July 26, 2018 14 On Demand Mobility Management 15 draft-ietf-dmm-ondemand-mobility-15 17 Abstract 19 Applications differ with respect to whether they need session 20 continuity and/or IP address reachability. The network providing the 21 same type of service to any mobile host and any application running 22 on the host yields inefficiencies. This document describes a 23 solution for taking the application needs into account by selectively 24 providing session continuity and IP address reachability on a per- 25 socket basis. 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 https://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 27, 2019. 44 Copyright Notice 46 Copyright (c) 2018 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 (https://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 . . . . . . . . . . . . . . . . . . . . . . . . 2 62 2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4 63 3. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 4 64 3.1. Types of IP Addresses . . . . . . . . . . . . . . . . . . 4 65 3.2. Granularity of Selection . . . . . . . . . . . . . . . . 6 66 3.3. On Demand Nature . . . . . . . . . . . . . . . . . . . . 6 67 3.4. Conveying the Desired Address Type . . . . . . . . . . . 7 68 4. Usage example . . . . . . . . . . . . . . . . . . . . . . . . 8 69 4.1. Pseudo-code example . . . . . . . . . . . . . . . . . . . 8 70 4.2. Message Flow example . . . . . . . . . . . . . . . . . . 10 71 5. Backwards Compatibility Considerations . . . . . . . . . . . 11 72 5.1. Applications . . . . . . . . . . . . . . . . . . . . . . 11 73 5.2. IP Stack in the Mobile Host . . . . . . . . . . . . . . . 12 74 5.3. Network Infrastructure . . . . . . . . . . . . . . . . . 12 75 5.4. Merging this work with RFC5014 . . . . . . . . . . . . . 12 76 6. Summary of New Definitions . . . . . . . . . . . . . . . . . 13 77 6.1. New APIs . . . . . . . . . . . . . . . . . . . . . . . . 13 78 6.2. New Flags . . . . . . . . . . . . . . . . . . . . . . . . 13 79 7. Security Considerations . . . . . . . . . . . . . . . . . . . 14 80 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 81 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14 82 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14 83 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 84 11.1. Normative References . . . . . . . . . . . . . . . . . . 15 85 11.2. Informative References . . . . . . . . . . . . . . . . . 15 86 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 88 1. Introduction 90 In the context of Mobile IP [RFC5563][RFC6275][RFC5213][RFC5944], the 91 following two attributes are defined for IP service provided to 92 mobile hosts: 94 Session continuity: The ability to maintain an ongoing transport 95 interaction by keeping the same local end-point IP address throughout 96 the life-time of the IP socket despite the mobile host changing its 97 point of attachment within the IP network topology. The IP address 98 of the host may change after closing the IP socket and before opening 99 a new one, but that does not jeopardize the ability of applications 100 using these IP sockets to work flawlessly. Session continuity is 101 essential for mobile hosts to maintain ongoing flows without any 102 interruption. 104 IP address reachability: The ability to maintain the same IP address 105 for an extended period of time. The IP address stays the same across 106 independent sessions, and even in the absence of any session. The IP 107 address may be published in a long-term registry (e.g., DNS), and is 108 made available for serving incoming (e.g., TCP) connections. IP 109 address reachability is essential for mobile hosts to use specific/ 110 published IP addresses. 112 Mobile IP is designed to provide both session continuity and IP 113 address reachability to mobile hosts. Architectures utilizing these 114 protocols (e.g., 3GPP, 3GPP2, WIMAX) ensure that any mobile host 115 attached to the compliant networks can enjoy these benefits. Any 116 application running on these mobile hosts is subjected to the same 117 treatment with respect to session continuity and IP address 118 reachability. 120 It should be noted that in reality not every application may need 121 these benefits. IP address reachability is required for applications 122 running as servers (e.g., a web server running on the mobile host). 123 But, a typical client application (e.g., web browser) does not 124 necessarily require IP address reachability. Similarly, session 125 continuity is not required for all types of applications either. 126 Applications performing brief communication (e.g., ping) can survive 127 without having session continuity support. 129 Achieving session continuity and IP address reachability with Mobile 130 IP incurs some cost. Mobile IP protocol forces the mobile host's IP 131 traffic to traverse a centrally-located router (Home Agent, HA), 132 which incurs additional transmission latency and use of additional 133 network resources, adds to the network CAPEX and OPEX, and decreases 134 the reliability of the network due to the introduction of a single 135 point of failure [RFC7333]. Therefore, session continuity and IP 136 address reachability SHOULD be provided only when necessary. 138 Furthermore, when an application needs session continuity, it may be 139 able to satisfy that need by using a solution above the IP layer, 140 such as MPTCP [RFC6824], SIP mobility [RFC3261], or an application- 141 layer mobility solution. These higher-layer solutions are not 142 subject to the same issues that arise with the use of Mobile IP since 143 they can utilize the most direct data path between the end-points. 144 But, if Mobile IP is being applied to the mobile host, the higher- 145 layer protocols are rendered useless because their operation is 146 inhibited by Mobile IP. Since Mobile IP ensures that the IP address 147 of the mobile host remains fixed (despite the location and movement 148 of the mobile host), the higher-layer protocols never detect the IP- 149 layer change and never engage in mobility management. 151 This document proposes a solution for applications running on mobile 152 hosts to indicate whether they need session continuity or IP address 153 reachability. The network protocol stack on the mobile host, in 154 conjunction with the network infrastructure, provides the required 155 type of service. It is for the benefit of both the users and the 156 network operators not to engage an extra level of service unless it 157 is absolutely necessary. It is expected that applications and 158 networks compliant with this specification will utilize this solution 159 to use network resources more efficiently. 161 2. Notational Conventions 163 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 164 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 165 document are to be interpreted as described in [RFC2119]. 167 3. Solution 169 3.1. Types of IP Addresses 171 Four types of IP addresses are defined with respect to mobility 172 management. 174 - Fixed IP Address 176 A Fixed IP address is an address with a guarantee to be valid for a 177 very long time, regardless of whether it is being used in any packet 178 to/from the mobile host, or whether or not the mobile host is 179 connected to the network, or whether it moves from one point-of- 180 attachment to another (with a different IP prefix) while it is 181 connected. 183 Fixed IP addresses are required by applications that need both 184 session continuity and IP address reachability. 186 - Session-lasting IP Address 188 A session-lasting IP address is an address with a guarantee to be 189 valid throughout the life-time of the socket(s) for which it was 190 requested. It is guaranteed to be valid even after the mobile host 191 had moved from one point-of-attachment to another (with a different 192 IP prefix). 194 Session-lasting IP addresses are required by applications that need 195 session continuity but do not need IP address reachability. 197 - Non-persistent IP Address 199 This type of IP address has no guarantee to exist after a mobile host 200 moves from one point-of-attachment to another, and therefore, no 201 session continuity nor IP address reachability are provided. The IP 202 address is created from an IP prefix that is obtained from the 203 serving IP gateway and is not maintained across gateway changes. In 204 other words, the IP prefix may be released and replaced by a new one 205 when the IP gateway changes due to the movement of the mobile host 206 forcing the creation of a new source IP address with the updated 207 allocated IP prefix. 209 - Graceful Replacement IP Address 211 In some cases, the network cannot guarantee the validity of the 212 provided IP prefix throughout the duration of the opened socket, but 213 can provide a limited graceful period of time in which both the 214 original IP prefix and a new one are valid. This enables the 215 application some flexibility in the transition from the existing 216 source IP address to the new one. 218 This gracefulness is still better than the non-persistence type of 219 address for applications that can handle a change in their source IP 220 address but require that extra flexibility. 222 Applications running as servers at a published IP address require a 223 Fixed IP Address. Long-standing applications (e.g., an SSH session) 224 may also require this type of address. Enterprise applications that 225 connect to an enterprise network via virtual LAN require a Fixed IP 226 Address. 228 Applications with short-lived transient sessions can use Session- 229 lasting IP Addresses. For example: Web browsers. 231 Applications with very short sessions, such as DNS clients and 232 instant messengers, can utilize Non-persistent IP Addresses. Even 233 though they could very well use Fixed or Session-lasting IP 234 Addresses, the transmission latency would be minimized when a Non- 235 persistent IP Addresses are used. 237 Applications that can tolerate a short interruption in connectivity 238 can use the Graceful-replacement IP addresses. For example, a 239 streaming client that has buffering capabilities. 241 3.2. Granularity of Selection 243 IP address type selection is made on a per-socket granularity. 244 Different parts of the same application may have different needs. 245 For example, the control-plane of an application may require a Fixed 246 IP Address in order to stay reachable, whereas the data-plane of the 247 same application may be satisfied with a Session-lasting IP Address. 249 3.3. On Demand Nature 251 At any point in time, a mobile host may have a combination of IP 252 addresses configured. Zero or more Non-persistent, zero or more 253 Session-lasting, zero or more Fixed and zero or more Graceful- 254 Replacement IP addresses may be configured by the IP stack of the 255 host. The combination may be as a result of the host policy, 256 application demand, or a mix of the two. 258 When an application requires a specific type of IP address and such 259 an address is not already configured on the host, the IP stack SHALL 260 attempt to configure one. For example, a host may not always have a 261 Session-lasting IP address available. When an application requests 262 one, the IP stack SHALL make an attempt to configure one by issuing a 263 request to the network (see Section 3.4 below for more details). If 264 the operation fails, the IP stack SHALL fail the associated socket 265 request and return an error. If successful, a Session-lasting IP 266 Address gets configured on the mobile host. If another socket 267 requests a Session-lasting IP address at a later time, the same IP 268 address may be served to that socket as well. When the last socket 269 using the same configured IP address is closed, the IP address may be 270 released or kept for future applications that may be launched and 271 require a Session-lasting IP address. 273 In some cases it might be preferable for the mobile host to request a 274 new Session-lasting IP address for a new opening of an IP socket 275 (even though one was already assigned to the mobile host by the 276 network and might be in use in a different, already active IP 277 sockets). It is outside the scope of this specification to define 278 criteria for choosing to use available addresses or choosing to 279 request new ones. It supports both alternatives (and any 280 combination). 282 It is outside the scope of this specification to define how the host 283 requests a specific type of prefix and how the network indicates the 284 type of prefix in its advertisement or in its reply to a request). 286 The following are matters of policy, which may be dictated by the 287 host itself, the network operator, or the system architecture 288 standard: 290 - The initial set of IP addresses configured on the host at boot 291 time. 293 - Permission to grant various types of IP addresses to a requesting 294 application. 296 - Determination of a default address type when an application does 297 not make any explicit indication, whether it already supports the 298 required API or it is just a legacy application. 300 3.4. Conveying the Desired Address Type 302 [RFC5014] introduced the ability of applications to influence the 303 source address selection with the IPV6_ADDR_PREFERENCE option at the 304 IPPROTO_IPV6 level. This option is used with setsockopt() and 305 getsockopt() calls to set/get address selection preferences. 307 Extending this further by adding more flags does not work when a 308 request for an address of a certain type results in requiring the IP 309 stack to wait for the network to provide the desired source IP prefix 310 and hence causing the setsockopt() call to block until the prefix is 311 allocated (or an error indication from the network is received). 313 Alternatively a new socket API is defined - getsc() which allows 314 applications to express their desired type of session continuity 315 service. The new getsc() API will return an IPv6 address that is 316 associated with the desired session continuity service and with 317 status information indicating whether or not the desired service was 318 provided. 320 An application that wishes to secure a desired service will call 321 getsc() with the service type definition and a place to contain the 322 provided IP address, and call bind() to associate that IP address 323 with the socket (See pseudo-code example in Section 4 below). 325 When the IP stack is required to use a source IP address of a 326 specified type, it can use an existing address, or request a new IP 327 prefix (of the same type) from the network and create a new one. If 328 the host does not already have an IPv6 prefix of that specific type, 329 it MUST request one from the network. 331 Using an existing address from an existing prefix is faster but might 332 yield a less optimal route (if a hand-off event occurred after its 333 configuration). On the other hand, acquiring a new IP prefix from 334 the network may be slower due to signaling exchange with the network. 336 Applications can control the stack's operation by setting a new flag 337 - ON_NET flag - which directs the IP stack whether to use a 338 preconfigured source IP address (if exists) or to request a new IPv6 339 prefix from the current serving network and configure a new IP 340 address. 342 This new flag is added to the set of flags in the 343 IPV6_ADDR_PREFERENCES option at the IPPROTO_IPV6 level. It is used 344 in setsockopt() to set the desired behavior. 346 4. Usage example 348 4.1. Pseudo-code example 350 The following example shows pseudo-code for creating a Stream socket 351 (TCP) with a Session-Lasting source IP address: 353 #include 354 #include 356 // Socket information 357 int s ; // socket id 359 // Source information (for secsc() and bind()) 360 sockaddr_in6 sourceInfo // my address and port for bind() 361 in6_addr sourceAddress // will contain the provisioned 362 // source IP address 363 uint8_t sc_type = IPV6_REQUIRE_SESSION_LASTING_IP ; 364 // For requesting a Session-Lasting 365 // source IP address 367 // Destination information (for connect()) 368 sockaddr_in6 serverInfo ; // server info for connect() 370 // Create an IPv6 TCP socket 371 s = socket(AF_INET6, SOCK_STREAM, 0) ; 372 if (s!=0) { 373 // Handle socket creation error 374 // ... 375 } // if socket creation failed 376 else { 377 // Socket creation is successful 378 // The application cannot connect yet, since it wants to use 379 // a Session-Lasting source IP address It needs to request 380 // the Session-Lasting source IP before connecting 381 if (setsc(s, &sourceAddress, &sc_type)) == 0){ 382 // setting session continuity to Session Lasting is 383 // Successful. sourceAddress now contains the Session- 384 // LAsting source IP address 385 // Bind to that source IP address 386 sourceInfo.sin6_family = AF_INET6 ; 387 sourceInfo.sin6_port = 0 // let the stack choose the port 388 sourceInfo.sin6_address = sourceAddress ; 389 // Use the source address that was 390 // generated by the setsc() call 391 if (bind(s, &sourceInfo, sizeof(sourceInfo))==0){ 392 // Set the desired server's information for connect() 393 serverInfo.sin6_family = AF_INET6 ; 394 serverInfo.sin6_port = SERVER_PORT_NUM ; 395 serverAddress.sin6_addr = SERVER_IPV6_ADDRESS ; 397 // Connect to the server 398 if (connect(s, &serverInfo, sizeof(serverInfo))==0) { 399 // connect successful (3-way handshake has been 400 // completed with Session-Lasting source address. 401 // Continue application functionality 402 // ... 403 } // if connect() is successful 404 else { 405 // connect failed 406 // ... 407 // Application code that handles connect failure and 408 // closes the socket 409 // ... 410 } // if connect() failed 411 } // if bind() successful 412 else { 413 // bind() failed 414 // ... 415 // Application code that handles bind failure and 416 // closes the socket 417 // ... 418 } // if bind() failed 419 } // if setsc() was successful and of a Session-Lasting 420 // source IP address was provided 421 else { 422 // application code that does not use Session-lasting IP 423 // address. The application may either connect without 424 // the desired Session-lasting service, or close the 425 // socket... 426 } // if setsc() failed 427 } // if socket was created successfully 429 // The rest of the application's code 430 // ... 432 4.2. Message Flow example 434 The following message flow illustrates a possible interaction for 435 achieving OnDemand functionality. It is an example of one scenario 436 and should not be regarded as the only scenario or the preferred one. 438 This flow describes the interaction between the following entities: 440 - Applications requiring different types of OnDemand service. 442 - The mobile host's IP stack. 444 - The network infrastructure providing the services. 446 In this example, the network infrastructure provides 2 IPv6 prefixes 447 upon attachment of the mobile host to the network: A Session-lasting 448 IPv6 prefix and a Non-persistent IPv6 prefix. Whenever the mobile 449 host moves to a different point-of-attachment, the network 450 infrastructure provides a new Non-persistent IPv6 address. 452 In this example, the network infrastructure does not support Fixed IP 453 addresses nor Graceful-replacement IP addresses. 455 Whenever an application opens an IP socket and requests a specific 456 IPv6 address type, the IP stack will provide one from its available 457 IPv6 prefixes or return an error message if the request cannot be 458 fulfilled. 460 Message Flow: 462 - The mobile device attaches to the network. 464 - The Network provides two IPv6 prefixes: PREFsl1 - a Session-lasting 465 IPv6 prefix and PREFnp1 - a Non-persistent IP v6 prefix. 467 - An application on the mobile host is launched. It opens an IP 468 socket and requests a Non-persistent IPv6 address. 470 - The IP stack provides IPnp1 which is generated from PREFnp1. 472 - Another application is launched, requesting a Non-persistent IPv6 473 address. 475 - The IP stack provides IPnp1 again. 477 - A third application is launched. This time, it requires a Session- 478 lasting IPv6 address. 480 - The IP stack provides IPsl1 which is generated from PREFsl1. 482 - The mobile hosts moves to a new point-of-attachment. 484 - The network provides a new Non-persistent IPv6 prefix - PREFnp2. 485 PREFnp1 is no longer valid. 487 - The applications that were given IPnp1 re-establish the socket and 488 receive a new IPv6 address - IPnp2 which is generated from PREFnp2 490 - The application that is using IPsl1 can still use it since the 491 network guaranteed that PREFsl1 will be valid even after moving to a 492 new point-of-attachment. 494 - A new application is launched, this time requiring a Graceful- 495 replacement IPv6 address. 497 - The IP stack returns setsc() with an error since the network does 498 not support this service. 500 - The application re-attempts to open a socket, this time requesting 501 a Session-lasting IPv6 address. 503 - The IP stack provides IPsl1. 505 5. Backwards Compatibility Considerations 507 Backwards compatibility support is REQUIRED by the following 3 types 508 of entities: 510 - The Applications on the mobile host 512 - The IP stack in the mobile host 514 - The network infrastructure 516 5.1. Applications 518 Legacy applications that do not support the OnDemand functionality 519 will use the legacy API and will not be able to take advantage of the 520 On-Demand Mobility feature. 522 Applications using the new OnDemand functionality MUST be aware that 523 they may be executed in legacy environments that do not support it. 524 Such environments may include a legacy IP stack on the mobile host, 525 legacy network infrastructure, or both. In either case, the API will 526 return an error code and the invoking applications may just give up 527 and use legacy calls. 529 5.2. IP Stack in the Mobile Host 531 New IP stacks MUST continue to support all legacy operations. If an 532 application does not use On-Demand functionality, the IP stack MUST 533 respond in a legacy manner. 535 If the network infrastructure supports On-Demand functionality, the 536 IP stack SHOULD follow the application request: If the application 537 requests a specific address type, the stack SHOULD forward this 538 request to the network. If the application does not request an 539 address type, the IP stack MUST NOT request an address type and leave 540 it to the network's default behavior to choose the type of the 541 allocated IP prefix. If an IP prefix was already allocated to the 542 host, the IP stack uses it and may not request a new one from the 543 network. 545 5.3. Network Infrastructure 547 The network infrastructure may or may not support the On-Demand 548 functionality. How the IP stack on the host and the network 549 infrastructure behave in case of a compatibility issue is outside the 550 scope of this API specification. 552 5.4. Merging this work with RFC5014 554 [RFC5014] defines new flags that may be used with setsockopt() to 555 influence source IP address selection for a socket. The list of 556 flags include: source home address, care-of address, temporary 557 address, public address CGA (Cryptographically Created Address) and 558 non-CGA. When applications require session continuity service and 559 use setsc() and bind(), they SHOULD NOT set the flags specified in 560 [RFC5014]. 562 However, if an application sets a specific option using setsockopt() 563 with one of the flags specified in [RFC5014] and also selects a 564 source IP address using setsc() and bind() the IP address that was 565 generated by setsc() and bound using bind() will be the one used by 566 traffic generated using that socket and options set by setsockopt() 567 will be ignored. 569 If bind() was not invoked after setsc() by the application, the IP 570 address generated by setsc() will not be used and traffic generated 571 by the socket will use a source IP address that complies with the 572 options selected by setsockopt(). 574 6. Summary of New Definitions 576 6.1. New APIs 578 setsc() enables applications to request a specific type of source IP 579 address in terms of session continuity. Its definition is: 581 int setsc(int sockfd, in6_addr *sourceAddress, sc_type addressType); 583 Where: 584 - sockfd - is the socket descriptor of the socket with which 585 a specific address type is associated 586 - sourceAddress - is a pointer to an area allocated for setsc() to 587 place the generated source IP address of the 588 desired session continuity type 589 - addressType - Is the desired type of session continuity service. 590 It is a 3-bit field containing one of the 591 following values: 592 0 - Reserved 593 1 - FIXED_IPV6_ADDRESS 594 2 - SESSION_LASTING_IPV6_ADDRESS 595 3 - NON_PERSISTENT_IPV6_ADDRESS 596 4 - GRACEFUL_REPLACEMENT_IPV6_ADDRESS 597 5-7 - Reserved 599 setsc() returns the status of the operation: 600 - 0 - Address was successfully generated 601 - EAI_REQUIREDIPNOTSUPPORTED - the required service type is not 602 supported 603 - EAI_REQUIREDIPFAILED - the network could not fulfill the desired 604 request 606 setsc() MAY block the invoking thread if it triggers the TCP/IP stack 607 to request a new IP prefix from the network to construct the desired 608 source IP address. If an IP prefix with the desired session 609 continuity features already exists (was previously allocated to the 610 mobile host) and the stack is not required to request a new one as a 611 result of setting the IPV6_REQUIRE_SRC_ON_NET flag (defined below), 612 setsc() MAY return immediately with the constructed IP address and 613 will not block the thread. 615 6.2. New Flags 617 The following flag is added to the list of flags in the 618 IPV6_ADDR_PREFERENCE option at the IPPROTO6 level: 620 IPV6_REQUIRE_SRC_ON_NET - set IP stack address allocation behavior 621 If set, the IP stack will request a new IPv6 prefix of the desired 622 type from the current serving network and configure a new source IP 623 address. If reset, the IP stack will use a preconfigured one if it 624 exists. If there is no preconfigured IP address of the desired type, 625 a new prefix will be requested and used for creating the IP address. 627 7. Security Considerations 629 The setting of certain IP address type on a given socket may be 630 restricted to privileged applications. For example, a Fixed IP 631 Address may be provided as a premium service and only certain 632 applications may be allowed to use them. Setting and enforcement of 633 such privileges are outside the scope of this document. 635 8. IANA Considerations 637 This document has no IANA considerations. 639 9. Contributors 641 This document was merged with [I-D.sijeon-dmm-use-cases-api-source]. 642 We would like to acknowledge the contribution of the following people 643 to that document as well: 645 Sergio Figueiredo 646 Altran Research, France 647 Email: sergio.figueiredo@altran.com 649 Younghan Kim 650 Soongsil University, Korea 651 Email: younghak@ssu.ac.kr 653 John Kaippallimalil 654 Huawei, USA 655 Email: john.kaippallimalil@huawei.com 657 10. Acknowledgements 659 We would like to thank Wu-chi Feng, Alexandru Petrescu, Jouni 660 Korhonen, Sri Gundavelli, Dave Dolson and Lorenzo Colitti for their 661 valuable comments and suggestions on this work. 663 11. References 664 11.1. Normative References 666 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 667 Requirement Levels", BCP 14, RFC 2119, 668 DOI 10.17487/RFC2119, March 1997, 669 . 671 [RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6 672 Socket API for Source Address Selection", RFC 5014, 673 DOI 10.17487/RFC5014, September 2007, 674 . 676 11.2. Informative References 678 [I-D.sijeon-dmm-use-cases-api-source] 679 Jeon, S., Figueiredo, S., Kim, Y., and J. Kaippallimalil, 680 "Use Cases and API Extension for Source IP Address 681 Selection", draft-sijeon-dmm-use-cases-api-source-07 (work 682 in progress), September 2017. 684 [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, 685 A., Peterson, J., Sparks, R., Handley, M., and E. 686 Schooler, "SIP: Session Initiation Protocol", RFC 3261, 687 DOI 10.17487/RFC3261, June 2002, 688 . 690 [RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V., 691 Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", 692 RFC 5213, DOI 10.17487/RFC5213, August 2008, 693 . 695 [RFC5563] Leung, K., Dommety, G., Yegani, P., and K. Chowdhury, 696 "WiMAX Forum / 3GPP2 Proxy Mobile IPv4", RFC 5563, 697 DOI 10.17487/RFC5563, February 2010, 698 . 700 [RFC5944] Perkins, C., Ed., "IP Mobility Support for IPv4, Revised", 701 RFC 5944, DOI 10.17487/RFC5944, November 2010, 702 . 704 [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility 705 Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 706 2011, . 708 [RFC6824] Ford, A., Raiciu, C., Handley, M., and O. Bonaventure, 709 "TCP Extensions for Multipath Operation with Multiple 710 Addresses", RFC 6824, DOI 10.17487/RFC6824, January 2013, 711 . 713 [RFC7333] Chan, H., Ed., Liu, D., Seite, P., Yokota, H., and J. 714 Korhonen, "Requirements for Distributed Mobility 715 Management", RFC 7333, DOI 10.17487/RFC7333, August 2014, 716 . 718 Authors' Addresses 720 Alper Yegin 721 Actility 722 Istanbul 723 Turkey 725 Email: alper.yegin@actility.com 727 Danny Moses 728 Intel Corporation 729 Petah Tikva 730 Israel 732 Email: danny.moses@intel.com 734 Kisuk Kweon 735 Samsung 736 Suwon 737 South Korea 739 Email: kisuk.kweon@samsung.com 741 Jinsung Lee 742 Samsung 743 Suwon 744 South Korea 746 Email: js81.lee@samsung.com 748 Jungshin Park 749 Samsung 750 Suwon 751 South Korea 753 Email: shin02.park@samsung.com 754 Seil Jeon 755 Sungkyunkwan University 756 Suwon 757 South Korea 759 Email: seiljeon@skku.edu