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Checking references for intended status: Informational ---------------------------------------------------------------------------- ** Obsolete normative reference: RFC 1981 (Obsoleted by RFC 8201) ** Obsolete normative reference: RFC 2460 (Obsoleted by RFC 8200) ** Obsolete normative reference: RFC 2671 (Obsoleted by RFC 6891) ** Obsolete normative reference: RFC 3315 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 3484 (Obsoleted by RFC 6724) ** Obsolete normative reference: RFC 3736 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 4307 (Obsoleted by RFC 8247) ** Obsolete normative reference: RFC 4835 (Obsoleted by RFC 7321) ** Obsolete normative reference: RFC 4941 (Obsoleted by RFC 8981) ** Obsolete normative reference: RFC 5996 (Obsoleted by RFC 7296) ** Obsolete normative reference: RFC 6106 (Obsoleted by RFC 8106) ** Obsolete normative reference: RFC 6204 (Obsoleted by RFC 7084) -- Obsolete informational reference (is this intentional?): RFC 793 (Obsoleted by RFC 9293) -- Obsolete informational reference (is this intentional?): RFC 2429 (Obsoleted by RFC 4629) -- Obsolete informational reference (is this intentional?): RFC 3775 (Obsoleted by RFC 6275) -- Obsolete informational reference (is this intentional?): RFC 5006 (Obsoleted by RFC 6106) Summary: 12 errors (**), 0 flaws (~~), 2 warnings (==), 6 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Internet Engineering Task Force E. Jankiewicz 3 Internet-Draft SRI International, Inc. 4 Obsoletes: 4294 (if approved) J. Loughney 5 Intended status: Informational Nokia 6 Expires: December 2, 2011 T. Narten 7 IBM Corporation 8 May 31, 2011 10 IPv6 Node Requirements 11 draft-ietf-6man-node-req-bis-11.txt 13 Abstract 15 This document defines requirements for IPv6 nodes. It is expected 16 that IPv6 will be deployed in a wide range of devices and situations. 17 Specifying the requirements for IPv6 nodes allows IPv6 to function 18 well and interoperate in a large number of situations and 19 deployments. 21 This document obsoletes RFC4294. 23 Status of this Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at http://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on December 2, 2011. 40 Copyright Notice 42 Copyright (c) 2011 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (http://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 This document may contain material from IETF Documents or IETF 56 Contributions published or made publicly available before November 57 10, 2008. The person(s) controlling the copyright in some of this 58 material may not have granted the IETF Trust the right to allow 59 modifications of such material outside the IETF Standards Process. 60 Without obtaining an adequate license from the person(s) controlling 61 the copyright in such materials, this document may not be modified 62 outside the IETF Standards Process, and derivative works of it may 63 not be created outside the IETF Standards Process, except to format 64 it for publication as an RFC or to translate it into languages other 65 than English. 67 Table of Contents 69 1. Requirements Language . . . . . . . . . . . . . . . . . . . . 5 70 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 71 2.1. Scope of This Document . . . . . . . . . . . . . . . . . . 6 72 2.2. Description of IPv6 Nodes . . . . . . . . . . . . . . . . 6 73 3. Abbreviations Used in This Document . . . . . . . . . . . . . 6 74 4. Sub-IP Layer . . . . . . . . . . . . . . . . . . . . . . . . . 7 75 5. IP Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 76 5.1. Internet Protocol Version 6 - RFC 2460 . . . . . . . . . . 8 77 5.2. Neighbor Discovery for IPv6 - RFC 4861 . . . . . . . . . . 8 78 5.3. Default Router Preferences and More-Specific Routes - 79 RFC 4191 . . . . . . . . . . . . . . . . . . . . . . . . . 9 80 5.4. SEcure Neighbor Discovery (SEND) - RFC 3971 . . . . . . . 10 81 5.5. IPv6 Router Advertisement Flags Option - RFC 5175 . . . . 10 82 5.6. Path MTU Discovery and Packet Size . . . . . . . . . . . . 10 83 5.6.1. Path MTU Discovery - RFC 1981 . . . . . . . . . . . . 10 84 5.7. IPv6 Jumbograms - RFC 2675 . . . . . . . . . . . . . . . . 11 85 5.8. ICMP for the Internet Protocol Version 6 (IPv6) - RFC 86 4443 . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 87 5.9. Addressing . . . . . . . . . . . . . . . . . . . . . . . . 11 88 5.9.1. IP Version 6 Addressing Architecture - RFC 4291 . . . 11 89 5.9.2. IPv6 Stateless Address Autoconfiguration - RFC 4862 . 11 90 5.9.3. Privacy Extensions for Address Configuration in 91 IPv6 - RFC 4941 . . . . . . . . . . . . . . . . . . . 12 92 5.9.4. Default Address Selection for IPv6 - RFC 3484 . . . . 12 93 5.9.5. Stateful Address Autoconfiguration (DHCPv6) - RFC 94 3315 . . . . . . . . . . . . . . . . . . . . . . . . . 13 95 5.10. Multicast Listener Discovery (MLD) for IPv6 . . . . . . . 13 96 6. DHCP vs. Router Advertisement Options for Host 97 Configuration . . . . . . . . . . . . . . . . . . . . . . . . 14 98 7. DNS and DHCP . . . . . . . . . . . . . . . . . . . . . . . . . 15 99 7.1. DNS . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 100 7.2. Dynamic Host Configuration Protocol for IPv6 (DHCPv6) 101 - RFC 3315 . . . . . . . . . . . . . . . . . . . . . . . . 15 102 7.2.1. Other Configuration Information . . . . . . . . . . . 15 103 7.2.2. Use of Router Advertisements in Managed 104 Environments . . . . . . . . . . . . . . . . . . . . . 15 105 7.3. IPv6 Router Advertisement Options for DNS 106 Configuration - RFC 6106 . . . . . . . . . . . . . . . . . 15 107 8. IPv4 Support and Transition . . . . . . . . . . . . . . . . . 16 108 8.1. Transition Mechanisms . . . . . . . . . . . . . . . . . . 16 109 8.1.1. Basic Transition Mechanisms for IPv6 Hosts and 110 Routers - RFC 4213 . . . . . . . . . . . . . . . . . . 16 111 9. Application Support . . . . . . . . . . . . . . . . . . . . . 16 112 9.1. Textual Representation of IPv6 Addresses - RFC 5952 . . . 16 113 9.2. Application Program Interfaces (APIs) . . . . . . . . . . 16 114 10. Mobility . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 115 11. Security . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 116 11.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 18 117 11.2. Transforms and Algorithms . . . . . . . . . . . . . . . . 19 118 12. Router-Specific Functionality . . . . . . . . . . . . . . . . 19 119 12.1. IPv6 Router Alert Option - RFC 2711 . . . . . . . . . . . 19 120 12.2. Neighbor Discovery for IPv6 - RFC 4861 . . . . . . . . . . 19 121 12.3. Stateful Address Autoconfiguration (DHCPv6) - RFC 3315 . . 19 122 13. Network Management . . . . . . . . . . . . . . . . . . . . . . 20 123 13.1. Management Information Base Modules (MIBs) . . . . . . . . 20 124 13.1.1. IP Forwarding Table MIB . . . . . . . . . . . . . . . 20 125 13.1.2. Management Information Base for the Internet 126 Protocol (IP) . . . . . . . . . . . . . . . . . . . . 20 127 14. Security Considerations . . . . . . . . . . . . . . . . . . . 20 128 15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 129 16. Authors and Acknowledgments . . . . . . . . . . . . . . . . . 21 130 16.1. Authors and Acknowledgments (Current Document) . . . . . . 21 131 16.2. Authors and Acknowledgments From RFC 4279 . . . . . . . . 21 132 17. Appendix: Changes from One ID version to Another . . . . . . . 22 133 17.1. Appendix: Changes from -10to -11 . . . . . . . . . . . . . 22 134 17.2. Appendix: Changes from -09 to -10 . . . . . . . . . . . . 22 135 17.3. Appendix: Changes from -08 to -09 . . . . . . . . . . . . 22 136 17.4. Appendix: Changes from -07 to -08 . . . . . . . . . . . . 22 137 17.5. Appendix: Changes from -06 to -07 . . . . . . . . . . . . 23 138 17.6. Appendix: Changes from -05 to -06 . . . . . . . . . . . . 23 139 17.7. Appendix: Changes from -04 to -05 . . . . . . . . . . . . 23 140 17.8. Appendix: Changes from -03 to -04 . . . . . . . . . . . . 24 141 18. Appendix: Changes from RFC 4294 . . . . . . . . . . . . . . . 24 142 19. References . . . . . . . . . . . . . . . . . . . . . . . . . . 25 143 19.1. Normative References . . . . . . . . . . . . . . . . . . . 25 144 19.2. Informative References . . . . . . . . . . . . . . . . . . 28 145 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 31 147 1. Requirements Language 149 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 150 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 151 document are to be interpreted as described in RFC 2119 [RFC2119]. 153 2. Introduction 155 This document defines common functionality required from both IPv6 156 hosts and routers. Many IPv6 nodes will implement optional or 157 additional features, but this document collects and summarizes 158 requirements from other published Standards Track documents in one 159 place. 161 This document tries to avoid discussion of protocol details, and 162 references RFCs for this purpose. This document is intended to be an 163 Applicability Statement and provide guidance as to which IPv6 164 specifications should be implemented in the general case, and which 165 specification may be of interest to specific deployment scenarios. 166 This document does not update any individual protocol document RFCs. 168 Although the document points to different specifications, it should 169 be noted that in many cases, the granularity of a particular 170 requirement will be smaller than a single specification, as many 171 specifications define multiple, independent pieces, some of which may 172 not be mandatory. In addition, most specifications define both 173 client and server behavior in the same specification, while many 174 implementations will be focused on only one of those roles. 176 This document defines a minimal level of requirement needed for a 177 device to provide useful internet service and considers a broad range 178 of device types and deployment scenarios. Because of the wide range 179 of deployment scenarios, the minimal requirements specified in this 180 document may not be sufficient for all deployment scenarios. It is 181 perfectly reasonable (and indeed expected) for other profiles to 182 define additional or stricter requirements appropriate for specific 183 usage and deployment environments. For example, this document does 184 not mandate that all clients support DHCP, but some deployment 185 scenarios may deem it appropriate to make such a requirement. For 186 example, government agencies in the USA have defined profiles for 187 specialized requirements for IPv6 in target environments [DODv6] and 188 [USGv6]. 190 As it is not always possible for an implementer to know the exact 191 usage of IPv6 in a node, an overriding requirement for IPv6 nodes is 192 that they should adhere to Jon Postel's Robustness Principle: 194 Be conservative in what you do, be liberal in what you accept from 195 others [RFC0793]. 197 2.1. Scope of This Document 199 IPv6 covers many specifications. It is intended that IPv6 will be 200 deployed in many different situations and environments. Therefore, 201 it is important to develop the requirements for IPv6 nodes to ensure 202 interoperability. 204 This document assumes that all IPv6 nodes meet the minimum 205 requirements specified here. 207 2.2. Description of IPv6 Nodes 209 From the Internet Protocol, Version 6 (IPv6) Specification [RFC2460], 210 we have the following definitions: 212 Description of an IPv6 Node 214 - a device that implements IPv6. 216 Description of an IPv6 router 218 - a node that forwards IPv6 packets not explicitly addressed to 219 itself. 221 Description of an IPv6 Host 223 - any node that is not a router. 225 3. Abbreviations Used in This Document 227 ATM Asynchronous Transfer Mode 228 AH Authentication Header 229 DAD Duplicate Address Detection 230 ESP Encapsulating Security Payload 231 ICMP Internet Control Message Protocol 232 IKE Internet Key Exchange 233 MIB Management Information Base 234 MLD Multicast Listener Discovery 235 MTU Maximum Transfer Unit 236 NA Neighbor Advertisement 237 NBMA Non-Broadcast Multiple Access 238 ND Neighbor Discovery 239 NS Neighbor Solicitation 240 NUD Neighbor Unreachability Detection 241 PPP Point-to-Point Protocol 242 PVC Permanent Virtual Circuit 243 SVC Switched Virtual Circuit 245 4. Sub-IP Layer 247 An IPv6 node must include support for one or more IPv6 link-layer 248 specifications. Which link-layer specifications an implementation 249 should include will depend upon what link-layers are supported by the 250 hardware available on the system. It is possible for a conformant 251 IPv6 node to support IPv6 on some of its interfaces and not on 252 others. 254 As IPv6 is run over new layer 2 technologies, it is expected that new 255 specifications will be issued. In the following, we list some of the 256 link-layers for which an IPv6 specification has been developed. It 257 is provided for information purposes only, and may not be complete. 259 - Transmission of IPv6 Packets over Ethernet Networks [RFC2464] 260 - IPv6 over ATM Networks [RFC2492] 261 - Transmission of IPv6 Packets over Frame Relay Networks 262 Specification [RFC2590] 263 - Transmission of IPv6 Packets over IEEE 1394 Networks [RFC3146] 264 - Transmission of IPv6, IPv4, and Address Resolution Protocol (ARP) 265 Packets over Fibre Channel [RFC4338] 266 - Transmission of IPv6 Packets over IEEE 802.15.4 Networks [RFC4944] 267 - Transmission of IPv6 via the IPv6 Convergence Sublayer over IEEE 268 802.16 Networks [RFC5121] 269 - IP version 6 over PPP [RFC5072] 271 In addition to traditional physical link-layers, it is also possible 272 to tunnel IPv6 over other protocols. Examples include: 274 - Teredo: Tunneling IPv6 over UDP through Network Address 275 Translations (NATs) [RFC4380] 276 - Section 3 of "Basic IPv6 Transition Mechanisms" [RFC4213] 278 5. IP Layer 279 5.1. Internet Protocol Version 6 - RFC 2460 281 The Internet Protocol Version 6 is specified in [RFC2460]. This 282 specification MUST be supported. 284 Any unrecognized extension headers or options MUST be processed as 285 described in RFC 2460. 287 The node MUST follow the packet transmission rules in RFC 2460. 289 Nodes MUST always be able to send, receive, and process fragment 290 headers. All conformant IPv6 implementations MUST be capable of 291 sending and receiving IPv6 packets; the forwarding functionality MAY 292 be supported. Overlapping fragments MUST be handled as described in 293 [RFC5722]. 295 RFC 2460 specifies extension headers and the processing for these 296 headers. 298 An IPv6 node MUST be able to process these headers. An exception is 299 Routing Header type 0 (RH0) which was deprecated by [RFC5095] due to 300 security concerns, and which MUST be treated as an unrecognized 301 routing type. 303 5.2. Neighbor Discovery for IPv6 - RFC 4861 305 Neighbor Discovery is defined in [RFC4861] and was updated by 306 [RFC5942]. Neighbor Discovery SHOULD be supported. RFC4861 states: 308 Unless specified otherwise (in a document that covers operating IP 309 over a particular link type) this document applies to all link 310 types. However, because ND uses link-layer multicast for some of 311 its services, it is possible that on some link types (e.g., NBMA 312 links) alternative protocols or mechanisms to implement those 313 services will be specified (in the appropriate document covering 314 the operation of IP over a particular link type). The services 315 described in this document that are not directly dependent on 316 multicast, such as Redirects, Next-hop determination, Neighbor 317 Unreachability Detection, etc., are expected to be provided as 318 specified in this document. The details of how one uses ND on 319 NBMA links is an area for further study. 321 Some detailed analysis of Neighbor Discovery follows: 323 Router Discovery is how hosts locate routers that reside on an 324 attached link. Hosts MUST support Router Discovery functionality. 326 Prefix Discovery is how hosts discover the set of address prefixes 327 that define which destinations are on-link for an attached link. 328 Hosts MUST support Prefix discovery. 330 Hosts MUST also implement Neighbor Unreachability Detection (NUD) for 331 all paths between hosts and neighboring nodes. NUD is not required 332 for paths between routers. However, all nodes MUST respond to 333 unicast Neighbor Solicitation (NS) messages. 335 Hosts MUST support the sending of Router Solicitations and the 336 receiving of Router Advertisements. The ability to understand 337 individual Router Advertisement options is dependent on supporting 338 the functionality making use of the particular option. 340 All nodes MUST support the Sending and Receiving of Neighbor 341 Solicitation (NS) and Neighbor Advertisement (NA) messages. NS and 342 NA messages are required for Duplicate Address Detection (DAD). 344 Hosts SHOULD support the processing of Redirect functionality. 345 Routers MUST support the sending of Redirects, though not necessarily 346 for every individual packet (e.g., due to rate limiting). Redirects 347 are only useful on networks supporting hosts. In core networks 348 dominated by routers, redirects are typically disabled. The sending 349 of redirects SHOULD be disabled by default on backbone routers. They 350 MAY be enabled by default on routers intended to support hosts on 351 edge networks. 353 "IPv6 Host-to-Router Load Sharing" [RFC4311] includes additional 354 recommendations on how to select from a set of available routers. 355 RFC 4311 SHOULD be supported. 357 5.3. Default Router Preferences and More-Specific Routes - RFC 4191 359 "Default Router Preferences and More-Specific Routes" [RFC4191] 360 provides support for nodes attached to multiple (different) networks 361 each providing routers that advertise themselves as default routers 362 via Router Advertisements. In some scenarios, one router may provide 363 connectivity to destinations the other router does not and choosing 364 the "wrong" default router can result in reachability failures. In 365 such cases, RFC4191 can help. 367 Small Office/Home Office (SOHO) deployments supported by routers 368 adhering to [RFC6204], use [RFC4191] to advertise routes to certain 369 local destinations. Consequently, nodes that will be deployed in 370 SOHO environments SHOULD implement [RFC4191]. 372 5.4. SEcure Neighbor Discovery (SEND) - RFC 3971 374 SEND [RFC3971] and Cryptographically Generated Address (CGA) 375 [RFC3972] provide a way to secure the message exchanges of Neighbor 376 Discovery. SEND is a new technology, in that it has no IPv4 377 counterpart but it has significant potential to address certain 378 classes of spoofing attacks. While there have been some 379 implementations of SEND, there has been only limited deployment 380 experience to date in using the technology. In addition, the IETF 381 working group Cga & Send maIntenance (csi) is currently working on 382 additional extensions intended to make SEND more attractive for 383 deployment. 385 At this time, SEND is considered optional and IPv6 nodes MAY provide 386 SEND functionality. 388 5.5. IPv6 Router Advertisement Flags Option - RFC 5175 390 Router Advertisements include an 8-bit field of single-bit Router 391 Advertisement flags. The Router Advertisement Flags Option extends 392 the number of available flag bits by 48 bits. At the time of this 393 writing, 6 of the original 8 bit flags have been assigned, while 2 394 remain available for future assignment. No flags have been defined 395 that make use of the new option, and thus strictly speaking, there is 396 no requirement to implement the option today. However, 397 implementations that are able to pass unrecognized options to a 398 higher level entity that may be able to understand them (e.g., a 399 user-level process using a "raw socket" facility), MAY take steps to 400 handle the option in anticipation of a future usage. 402 5.6. Path MTU Discovery and Packet Size 404 5.6.1. Path MTU Discovery - RFC 1981 406 "Path MTU Discovery" [RFC1981] SHOULD be supported. From [RFC2460]: 408 It is strongly recommended that IPv6 nodes implement Path MTU 409 Discovery [RFC1981], in order to discover and take advantage of 410 path MTUs greater than 1280 octets. However, a minimal IPv6 411 implementation (e.g., in a boot ROM) may simply restrict itself to 412 sending packets no larger than 1280 octets, and omit 413 implementation of Path MTU Discovery. 415 The rules in [RFC2460] and [RFC5722] MUST be followed for packet 416 fragmentation and reassembly. 418 One operational issue with Path MTU discovery occurs when firewalls 419 block ICMP Packet Too Big messages. Path MTU discovery relies on 420 such messages to determine what size messages can be successfully 421 sent. Packetization Layer Path MTU Discovery [RFC4821] avoids having 422 a dependency on Packet Too Big messages. 424 5.7. IPv6 Jumbograms - RFC 2675 426 IPv6 Jumbograms [RFC2675] are an optional extension that allow the 427 sending of IP datagrams larger than 65.535 bytes. IPv6 Jumbograms 428 make use of IPv6 hop-by-hop options and are only suitable on paths in 429 which every hop and link are capable of supporting Jumbograms (e.g., 430 within a campus or datacenter). To date, few implementations exist 431 and there is essentially no reported experience from usage. 432 Consequently, IPv6 Jumbograms [RFC2675] remain optional at this time. 434 5.8. ICMP for the Internet Protocol Version 6 (IPv6) - RFC 4443 436 ICMPv6 [RFC4443] MUST be supported. "Extended ICMP to Support Multi- 437 Part Messages" [RFC4884] MAY be supported. 439 5.9. Addressing 441 5.9.1. IP Version 6 Addressing Architecture - RFC 4291 443 The IPv6 Addressing Architecture [RFC4291] MUST be supported. 445 5.9.2. IPv6 Stateless Address Autoconfiguration - RFC 4862 447 Hosts MUST support IPv6 Stateless Address Autoconfiguration as 448 defined in [RFC4862]. Configuration of static address(es) may be 449 supported as well. 451 Nodes that are routers MUST be able to generate link local addresses 452 as described in RFC 4862 [RFC4862]. 454 From 4862: 456 The autoconfiguration process specified in this document applies 457 only to hosts and not routers. Since host autoconfiguration uses 458 information advertised by routers, routers will need to be 459 configured by some other means. However, it is expected that 460 routers will generate link-local addresses using the mechanism 461 described in this document. In addition, routers are expected to 462 successfully pass the Duplicate Address Detection procedure 463 described in this document on all addresses prior to assigning 464 them to an interface. 466 All nodes MUST implement Duplicate Address Detection. Quoting from 467 Section 5.4 of RFC 4862: 469 Duplicate Address Detection MUST be performed on all unicast 470 addresses prior to assigning them to an interface, regardless of 471 whether they are obtained through stateless autoconfiguration, 472 DHCPv6, or manual configuration, with the following [exceptions 473 noted therein]. 475 "Optimistic Duplicate Address Detection (DAD) for IPv6" [RFC4429] 476 specifies a mechanism to reduce delays associated with generating 477 addresses via stateless address autoconfiguration [RFC4862]. RFC 478 4429 was developed in conjunction with Mobile IPv6 in order to reduce 479 the time needed to acquire and configure addresses as devices quickly 480 move from one network to another, and it is desirable to minimize 481 transition delays. For general purpose devices, RFC 4429 remains 482 optional at this time. 484 5.9.3. Privacy Extensions for Address Configuration in IPv6 - RFC 4941 486 Privacy Extensions for Stateless Address Autoconfiguration [RFC4941] 487 addresses a specific problem involving a client device whose user is 488 concerned about its activity or location being tracked. The problem 489 arises both for a static client and for one that regularly changes 490 its point of attachment to the Internet. When using Stateless 491 Address Autoconfiguration [RFC4862], the Interface Identifier portion 492 of formed addresses stays constant and is globally unique. Thus, 493 although a node's global IPv6 address will change if it changes its 494 point of attachment, the Interface Identifier portion of those 495 addresses remain the same, making it possible for servers to track 496 the location of an individual device as it moves around, or its 497 pattern of activity if it remains in one place. This may raise 498 privacy concerns as described in [RFC4862]. 500 In such situations, RFC4941 SHOULD be implemented. In other cases, 501 such as with dedicated servers in a data center, RFC4941 provides 502 limited or no benefit. 504 Implementers of "RFC4941 should be aware that certain addresses are 505 reserved and should not be chosen for use as temporary addresses. 506 Consult "Reserved IPv6 Interface Identifiers" [RFC5453] for more 507 details. 509 5.9.4. Default Address Selection for IPv6 - RFC 3484 511 The rules specified in the Default Address Selection for IPv6 512 [RFC3484] document MUST be implemented. IPv6 nodes will need to deal 513 with multiple addresses configured simultaneously. 515 5.9.5. Stateful Address Autoconfiguration (DHCPv6) - RFC 3315 517 DHCPv6 [RFC3315] can be used to obtain and configure addresses. In 518 general, a network may provide for the configuration of addresses 519 through Router Advertisements, DHCPv6 or both. There will be a wide 520 range of IPv6 deployment models and differences in address assignment 521 requirements, some of which may require DHCPv6 for address 522 assignment. Consequently all hosts SHOULD implement address 523 configuration via DHCPv6. 525 In the absence of a router, IPv6 nodes using DHCP for address 526 assignment MAY initiate DHCP to obtain IPv6 addresses and other 527 configuration information, as described in Section 5.5.2 of 528 [RFC4862]. 530 5.10. Multicast Listener Discovery (MLD) for IPv6 532 Nodes that need to join multicast groups MUST support MLDv1 533 [RFC2710]. MLDv1 is needed by any node that is expected to receive 534 and process multicast traffic. Note that Neighbor Discovery (as used 535 on most link types -- see Section 5.2) depends on multicast and 536 requires that nodes join Solicited Node multicast addresses. 538 MLDv2 [RFC3810] extends the functionality of MLDv1 by supporting 539 Source-Specific Multicast. The original MLDv2 protocol [RFC3810] 540 supporting Source-Specific Multicast [RFC4607] supports two types of 541 "filter modes". Using an INCLUDE filter, a node indicates a 542 multicast group along with a list of senders for that group it wishes 543 to receive traffic from. Using an EXCLUDE filter, a node indicates a 544 multicast group along with a list of senders it wishes to exclude 545 receiving traffic from. In practice, operations to block source(s) 546 using EXCLUDE mode are rarely used, but add considerable 547 implementation complexity to MLDv2. Lightweight MLDv2 [RFC5790] is a 548 simplified subset of the original MLDv2 specification that omits 549 EXCLUDE filter mode to specify undesired source(s). 551 Nodes SHOULD implement either MLDv2 [RFC3810] or Lightweight MLDv2 552 [RFC5790]. Specifically, nodes supporting applications using Source- 553 Specific Multicast that expect to take advantage of MLDv2's EXCLUDE 554 functionality [RFC3810] MUST support MLDv2 as defined in [RFC3810], 555 [RFC4604] and [RFC4607]. Nodes supporting applications that expect 556 to only take advantage of MLDv2's INCLUDE functionality as well as 557 Any-Source Multicast will find it sufficient to support MLDv2 as 558 defined in [RFC5790]. 560 If a node only supports applications that use Any-Source Multicast 561 (i.e, they do not use source-specific multicast), implementing MLDv1 562 [RFC2710] is sufficient. In all cases, however, nodes are strongly 563 encouraged to implement MLDv2 or Lightweight MLDv2 rather than MLDv1, 564 as the presence of a single MLDv1 participant on a link requires that 565 all other nodes on the link operate in version 1 compatibility mode. 567 When MLDv1 is used, the rules in the Source Address Selection for the 568 Multicast Listener Discovery (MLD) Protocol [RFC3590] MUST be 569 followed. 571 6. DHCP vs. Router Advertisement Options for Host Configuration 573 In IPv6, there are two main protocol mechanisms for propagating 574 configuration information to hosts: Router Advertisements and DHCP. 575 Historically, RA options have been restricted to those deemed 576 essential for basic network functioning and for which all nodes are 577 configured with exactly the same information. Examples include the 578 Prefix Information Options, the MTU option, etc. On the other hand, 579 DHCP has generally been preferred for configuration of more general 580 parameters and for parameters that may be client-specific. That 581 said, identifying the exact line on whether a particular option 582 should be configured via DHCP vs. an RA option has not always been 583 easy. Generally speaking, however, there has been a desire to define 584 only one mechanism for configuring a given option, rather than 585 defining multiple (different) ways of configuring the same 586 information. 588 One issue with having multiple ways of configuring the same 589 information is that if a host chooses one mechanism, but the network 590 operator chooses a different mechanism, interoperability suffers. 591 For "closed" environments, where the network operator has significant 592 influence over what devices connect to the network and thus what 593 configuration mechanisms they support, the operator may be able to 594 ensure that a particular mechanism is supported by all connected 595 hosts. In more open environments, however, where arbitrary devices 596 may connect (e.g., a WIFI hotspot), problems can arise. To maximize 597 interoperability in such environments hosts would need to implement 598 multiple configuration mechanisms to ensure interoperability. 600 Originally in IPv6, configuring information about DNS servers was 601 performed exclusively via DHCP. In 2007, an RA option was defined, 602 but was published as Experimental [RFC5006]. In 2010, "IPv6 Router 603 Advertisement Options for DNS Configuration" [RFC6106] was published 604 as a Standards Track Document. Consequently, DNS configuration 605 information can now be learned either through DHCP or through RAs. 606 Hosts will need to decide which mechanism (or whether both) should be 607 implemented. Specific guidance regarding DNS server discovery is 608 discussed in Section 7. 610 7. DNS and DHCP 612 7.1. DNS 614 DNS is described in [RFC1034], [RFC1035], [RFC3363], and [RFC3596]. 615 Not all nodes will need to resolve names; those that will never need 616 to resolve DNS names do not need to implement resolver functionality. 617 However, the ability to resolve names is a basic infrastructure 618 capability that applications rely on and most nodes will need to 619 provide support. All nodes SHOULD implement stub-resolver [RFC1034] 620 functionality, as in RFC 1034, Section 5.3.1, with support for: 622 - AAAA type Resource Records [RFC3596]; 623 - reverse addressing in ip6.arpa using PTR records [RFC3596]; 624 - EDNS0 [RFC2671] to allow for DNS packet sizes larger than 512 625 octets. 627 Those nodes are RECOMMENDED to support DNS security extensions 628 [RFC4033], [RFC4034], and [RFC4035]. 630 Those nodes are NOT RECOMMENDED to support the experimental A6 631 Resource Records [RFC3363]. 633 7.2. Dynamic Host Configuration Protocol for IPv6 (DHCPv6) - RFC 3315 635 7.2.1. Other Configuration Information 637 IPv6 nodes use DHCP [RFC3315] to obtain address configuration 638 information (See Section 5.8.5) and to obtain additional (non- 639 address) configuration. If a host implementation supports 640 applications or other protocols that require configuration that is 641 only available via DHCP, hosts SHOULD implement DHCP. For 642 specialized devices on which no such configuration need is present, 643 DHCP may not be necessary. 645 An IPv6 node can use the subset of DHCP (described in [RFC3736]) to 646 obtain other configuration information. 648 7.2.2. Use of Router Advertisements in Managed Environments 650 Nodes using the Dynamic Host Configuration Protocol for IPv6 (DHCPv6) 651 are expected to determine their default router information and on- 652 link prefix information from received Router Advertisements. 654 7.3. IPv6 Router Advertisement Options for DNS Configuration - RFC 6106 656 Router Advertisements have historically limited options to those that 657 are critical to basic IPv6 functioning. Originally, DNS 658 configuration was not included as an RA option and DHCP was the 659 recommended way to obtain DNS configuration information. Over time, 660 the thinking surrounding such an option has evolved. It is now 661 generally recognized that few nodes can function adequately without 662 having access to a working DNS resolver. RFC 5006 was published as 663 an experimental document in 2007, and recently, a revised version was 664 placed on the Standards Track [RFC6106]. 666 Implementations SHOULD implement the DNS RA option [RFC6106]. 668 8. IPv4 Support and Transition 670 IPv6 nodes MAY support IPv4. 672 8.1. Transition Mechanisms 674 8.1.1. Basic Transition Mechanisms for IPv6 Hosts and Routers - RFC 675 4213 677 If an IPv6 node implements dual stack and tunneling, then [RFC4213] 678 MUST be supported. 680 9. Application Support 682 9.1. Textual Representation of IPv6 Addresses - RFC 5952 684 Software that allows users and operators to input IPv6 addresses in 685 text form SHOULD support "A Recommendation for IPv6 Address Text 686 Representation" [RFC5952]. 688 9.2. Application Program Interfaces (APIs) 690 There are a number of IPv6-related APIs. This document does not 691 mandate the use of any, because the choice of API does not directly 692 relate to on-the-wire behavior of protocols. Implementers, however, 693 would be advised to consider providing a common API, or reviewing 694 existing APIs for the type of functionality they provide to 695 applications. 697 "Basic Socket Interface Extensions for IPv6" [RFC3493] provides IPv6 698 functionality used by typical applications. Implementers should note 699 that RFC3493 has been picked up and further standardized by POSIX 700 [POSIX]. 702 "Advanced Sockets Application Program Interface (API) for IPv6" 703 [RFC3542] provides access to advanced IPv6 features needed by 704 diagnostic and other more specialized applications. 706 "IPv6 Socket API for Source Address Selection" [RFC5014] provides 707 facilities that allow an application to override the default Source 708 Address Selection rules of [RFC3484]. 710 "Socket Interface Extensions for Multicast Source Filters" [RFC3678] 711 provides support for expressing source filters on multicast group 712 memberships. 714 "Extension to Sockets API for Mobile IPv6" [RFC4584] provides 715 application support for accessing and enabling Mobile IPv6 features. 716 [RFC3775] 718 10. Mobility 720 Mobile IPv6 [RFC3775] and associated specifications [RFC3776] 721 [RFC4877] allow a node to change its point of attachment within the 722 Internet, while maintaining (and using) a permanent address. All 723 communication using the permanent address continues to proceed as 724 expected even as the node moves around. The definition of Mobile IP 725 includes requirements for the following types of nodes: 727 - mobile nodes 728 - correspondent nodes with support for route optimization 729 - home agents 730 - all IPv6 routers 732 At the present time, Mobile IP has seen only limited implementation 733 and no significant deployment, partly because it originally assumed 734 an IPv6-only environment, rather than a mixed IPv4/IPv6 Internet. 735 Recently, additional work has been done to support mobility in mixed- 736 mode IPv4 and IPv6 networks[RFC5555]. 738 More usage and deployment experience is needed with mobility before 739 any specific approach can be recommended for broad implementation in 740 all hosts and routers. Consequently, [RFC3775], [RFC5555], and 741 associated standards such as [RFC4877] are considered a MAY at this 742 time. 744 11. Security 746 This section describes the specification for security for IPv6 nodes. 748 Achieving security in practice is a complex undertaking. Operational 749 procedures, protocols, key distribution mechanisms, certificate 750 management approaches, etc. are all components that impact the level 751 of security actually achieved in practice. More importantly, 752 deficiencies or a poor fit in any one individual component can 753 significantly reduce the overall effectiveness of a particular 754 security approach. 756 IPsec provides channel security at the Internet layer, making it 757 possible to provide secure communication for all (or a subset of) 758 communication flows at the IP layer between pairs of internet nodes. 759 IPsec provides sufficient flexibility and granularity that individual 760 TCP connections can (selectively) be protected, etc. 762 Although IPsec can be used with manual keying in some cases, such 763 usage has limited applicability and is not recommended. 765 A range of security technologies and approaches proliferate today 766 (e.g., IPsec, TLS, SSH, etc.) No one approach has emerged as an 767 ideal technology for all needs and environments. Moreover, IPsec is 768 not viewed as the ideal security technology in all cases and is 769 unlikely to displace the others. 771 Previously, IPv6 mandated implementation of IPsec and recommended the 772 key management approach of IKE. This document updates that 773 recommendation by making support of the IP Security Architecture [RFC 774 4301] a SHOULD for all IPv6 nodes. Note that the IPsec Architecture 775 requires (e.g., Sec. 4.5 of RFC 4301) the implementation of both 776 manual and automatic key management. Currently the default automated 777 key management protocol to implement is IKEv2 [RFC5996]. 779 This document recognizes that there exists a range of device types 780 and environments where other approaches to security than IPsec can be 781 justified. For example, special-purpose devices may support only a 782 very limited number or type of applications and an application- 783 specific security approach may be sufficient for limited management 784 or configuration capabilities. Alternatively, some devices my run on 785 extremely constrained hardware (e.g., sensors) where the full IP 786 Security Architecture is not justified. 788 11.1. Requirements 790 "Security Architecture for the Internet Protocol" [RFC4301] SHOULD be 791 supported by all IPv6 nodes. Note that the IPsec Architecture 792 requires (e.g., Sec. 4.5 of RFC 4301) the implementation of both 793 manual and automatic key management. Currently the default automated 794 key management protocol to implement is IKEv2. As required in 795 [RFC4301], IPv6 nodes implementing the IPsec Architecture MUST 796 implement ESP [RFC4303] and MAY implement AH [RFC4302]. 798 11.2. Transforms and Algorithms 800 The current set of mandatory-to-implement algorithms for the IP 801 Security Architecture are defined in 'Cryptographic Algorithm 802 Implementation Requirements For ESP and AH' [RFC4835]. IPv6 nodes 803 implementing the IP Security Architecture MUST conform to the 804 requirements in [RFC4835]. Preferred cryptographic algorithms often 805 change more frequently than security protocols. Therefore 806 implementations MUST allow for migration to new algorithms, as 807 RFC4835 is replaced or updated in the future. 809 The current set of mandatory-to-implement algorithms for IKEv2 are 810 defined in 'Cryptographic Algorithms for Use in the Internet Key 811 Exchange Version 2 (IKEv2)' [RFC4307]. IPv6 nodes implementing IKEv2 812 MUST conform to the requirements in [RFC4307] and/or any future 813 updates or replacements to [RFC4307]. 815 12. Router-Specific Functionality 817 This section defines general host considerations for IPv6 nodes that 818 act as routers. Currently, this section does not discuss routing- 819 specific requirements. 821 12.1. IPv6 Router Alert Option - RFC 2711 823 The IPv6 Router Alert Option [RFC2711] is an optional IPv6 Hop-by-Hop 824 Header that is used in conjunction with some protocols (e.g., RSVP 825 [RFC2205] or MLD [RFC2710]). The Router Alert option will need to be 826 implemented whenever protocols that mandate its usage (e.g., MLD) are 827 implemented. See Section 5.9. 829 12.2. Neighbor Discovery for IPv6 - RFC 4861 831 Sending Router Advertisements and processing Router Solicitation MUST 832 be supported. 834 Section 7 of RFC 3775 includes some mobility-specific extensions to 835 Neighbor Discovery. Routers SHOULD implement Sections 7.3 and 7.5, 836 even if they do not implement Home Agent functionality. 838 12.3. Stateful Address Autoconfiguration (DHCPv6) - RFC 3315 840 A single DHCP server ([RFC3315] or [RFC4862]) can provide 841 configuration information to devices directly attached to a shared 842 link, as well as to devices located elsewhere within a site. 843 Communication between a client and a DHCP server located on different 844 links requires the use of DHCP relay agents on routers. 846 In simple deployments, consisting of a single router and either a 847 single LAN, or multiple LANs attached to the single router, together 848 with a WAN connection, a DHCP server embedded within the router is 849 one common deployment scenario (e.g., [RFC6204]). However, there is 850 no need for relay agents in such scenarios. 852 In more complex deployment scenarios, such as within enterprise or 853 service provider networks, the use of DHCP requires some level of 854 configuration, in order to configure relay agents, DHCP servers, etc. 855 In such environments, the DHCP server might even be run on a 856 traditional server, rather than as part of a router. 858 Because of the wide range of deployment scenarios, support for DHCP 859 server functionality on routers is optional. However, routers 860 targeted for deployment within more complex scenarios (as described 861 above) SHOULD support relay agent functionality. Note that "Basic 862 Requirements for IPv6 Customer Edge Routers" [RFC6204] requires 863 implementation of a DHCPv6 server function in IPv6 CE routers. 865 13. Network Management 867 Network Management MAY be supported by IPv6 nodes. However, for IPv6 868 nodes that are embedded devices, network management may be the only 869 possible way of controlling these nodes. 871 13.1. Management Information Base Modules (MIBs) 873 The following two MIB modules SHOULD be supported by nodes that 874 support an SNMP agent. 876 13.1.1. IP Forwarding Table MIB 878 IP Forwarding Table MIB [RFC4292] SHOULD be supported by nodes that 879 support an SNMP agent. 881 13.1.2. Management Information Base for the Internet Protocol (IP) 883 IP MIB [RFC4293] SHOULD be supported by nodes that support an SNMP 884 agent. 886 14. Security Considerations 888 This document does not directly affect the security of the Internet, 889 beyond the security considerations associated with the individual 890 protocols. 892 Security is also discussed in Section 10 above. 894 15. IANA Considerations 896 This document has no requests for IANA. 898 16. Authors and Acknowledgments 900 16.1. Authors and Acknowledgments (Current Document) 902 For this version of the IPv6 Node Requirements document, the authors 903 would like to thank Hitoshi Asaeda, Brian Carpenter, Tim Chown, Ralph 904 Droms, Sheila Frankel, Sam Hartman, Bob Hinden, Paul Hoffman, Pekka 905 Savola, Yaron Sheffer and Dave Thaler for their comments. 907 16.2. Authors and Acknowledgments From RFC 4279 909 The original version of this document (RFC 4279) was written by the 910 IPv6 Node Requirements design team: 912 Jari Arkko 913 jari.arkko@ericsson.com 914 Marc Blanchet 915 marc.blanchet@viagenie.qc.ca 916 Samita Chakrabarti 917 samita.chakrabarti@eng.sun.com 918 Alain Durand 919 alain.durand@sun.com 920 Gerard Gastaud 921 gerard.gastaud@alcatel.fr 922 Jun-ichiro itojun Hagino 923 itojun@iijlab.net 924 Atsushi Inoue 925 inoue@isl.rdc.toshiba.co.jp 926 Masahiro Ishiyama 927 masahiro@isl.rdc.toshiba.co.jp 928 John Loughney 929 john.loughney@nokia.com 930 Rajiv Raghunarayan 931 raraghun@cisco.com 932 Shoichi Sakane 933 shouichi.sakane@jp.yokogawa.com 934 Dave Thaler 935 dthaler@windows.microsoft.com 936 Juha Wiljakka 937 juha.wiljakka@Nokia.com 939 The authors would like to thank Ran Atkinson, Jim Bound, Brian 940 Carpenter, Ralph Droms, Christian Huitema, Adam Machalek, Thomas 941 Narten, Juha Ollila, and Pekka Savola for their comments. Thanks to 942 Mark Andrews for comments and corrections on DNS text. Thanks to 943 Alfred Hoenes for tracking the updates to various RFCs. 945 17. Appendix: Changes from One ID version to Another 947 RFC Editor: Please remove this section upon publication. 949 17.1. Appendix: Changes from -10to -11 951 1. Editorial cleanups. 952 2. Added section on DHCPv6 for servers. SHOULD implement relay 953 agent functionality, MAY implement servers. 955 17.2. Appendix: Changes from -09 to -10 957 1. With changes in requirements for IPsec and Routing Headers, 958 clarified language regarding processing of unknown options, and 959 removed paragraph lising which extension headers were required to 960 be implemented. 961 2. Removed "RFC4292-bis" from title. 962 3. Expanded the text on Jumbograms. 963 4. Changed recommendation of DHCPv6 from MAY to SHOULD. 964 5. Expanded the text on RFC4191, and changed recommendation from MAY 965 to SHOULD. 967 17.3. Appendix: Changes from -08 to -09 969 1. Updated MLD section to include reference to Lightweight MLD 970 [RFC5790] 972 17.4. Appendix: Changes from -07 to -08 974 1. Dropped reference to "Transmission of IPv6 over IPv4 Domains 975 without Explicit Tunnels" [RFC2429] in favor of a reference to 976 tunneling via Basic IPv6 Transition Mechanisms (RFC4313). 977 2. Added reference to "Default Router Preferences and More-Specific 978 Routes" [RFC4191] as a MAY. 980 3. Added reference to "Optimistic Duplicate Address Detection (DAD) 981 for IPv6" (RFC4429). 982 4. Added reference to RFC4941 "Reserved IPv6 Interface Identifiers" 983 5. Added Section on APIs. References are FYI, and none are 984 required. 985 6. Added text that "IPv6 Host-to-Router Load Sharing" [RFC4311] 986 SHOULD be implemented 987 7. Added reference to RFC5722 (Overlapping Fragments), made it a 988 MUST to implement. 989 8. Made "A Recommendation for IPv6 Address Text Representation" 990 [RFC5952] a SHOULD. 992 17.5. Appendix: Changes from -06 to -07 994 1. Added recommendation that routers implement Section 7.3 and 7.5 995 of RFC 3775. 996 2. "IPv6 Router Advertisement Options for DNS Configuration" (RFC 997 6106) has been published. 998 3. Further clarifications to the MLD recommendation. 999 4. "Extended ICMP to Support Multi- Part Messages" [RFC4884] added 1000 as a MAY. 1001 5. Added pointer to subnet clarification document (RFC 5942). 1002 6. Added text that "IPv6 Host-to-Router Load Sharing" [RFC4311] 1003 SHOULD be implemented 1004 7. Added reference to RFC5722 (Overlapping Fragments), made it a 1005 MUST to implement. 1006 8. Made "A Recommendation for IPv6 Address Text Representation" 1007 [RFC5952] a SHOULD. 1009 17.6. Appendix: Changes from -05 to -06 1011 1. Completely revised IPsec/IKEv2 section. Text has been discussed 1012 by 6man and saag. 1013 2. Added text to introduction clarifying that this document applies 1014 to general nodes and that other profiles may be more specific in 1015 their requirements 1016 3. Editorial cleanups in Neighbor Discovery section in particular. 1017 Text made more crisp. 1018 4. Moved some of the DHCP text around. Moved stateful address 1019 discussion to Section 5.8.5. 1020 5. Added additional nuance to the redirect requirements w.r.t. 1021 default configuration setting. 1023 17.7. Appendix: Changes from -04 to -05 1025 1. Cleaned up IPsec section, but key questions (MUST vs. SHOULD) 1026 still open. 1028 2. Added background section on DHCP vs. RA options. 1029 3. Added SHOULD recommendation for DNS configuration vi RAs 1030 (RFC5006bis). 1031 4. Cleaned up DHCP section, as it was referring to the M&O bits. 1032 5. Cleaned up the Security Considerations Section. 1034 17.8. Appendix: Changes from -03 to -04 1036 1. Updated the Introduction to indicate document is an applicability 1037 statement 1038 2. Updated the section on Mobility protocols 1039 3. Changed Sub-IP Layer Section to just list relevant RFCs, and 1040 added some more RFCs. 1041 4. Added Section on SEND (make it a MAY) 1042 5. Redid Section on Privacy Extensions (RFC4941) to add more nuance 1043 to recommendation 1044 6. Redid section on Mobility, and added additional RFCs. 1046 18. Appendix: Changes from RFC 4294 1048 1. There have been many editorial clarifications as well as 1049 significant additions and updates. While this section 1050 highlights some of the changes, readers should not rely on this 1051 section for a comprehensive list of all changes. 1052 2. Updated the Introduction to indicate document is an 1053 applicability statement and that this document is aimed at 1054 general nodes. 1055 3. Significantly updated the section on Mobility protocols, adding 1056 references and downgrading previous SHOULDs to MAY. 1057 4. Changed Sub-IP Layer Section to just list relevant RFCs, and 1058 added some more RFCs. 1059 5. Added Section on SEND (it is a MAY) 1060 6. Revised Section on Privacy Extensions (RFC4941) to add more 1061 nuance to recommendation. 1062 7. Completely revised IPsec/IKEv2 Section, downgrading overall 1063 recommendation to a SHOULD. 1064 8. Upgraded recommendation of DHCPv6 to SHOULD. 1065 9. Added background section on DHCP vs RA options, added SHOULD 1066 recommendation sfor DNS configuration via RAs (RFC 6106), 1067 cleaned up DHCP recommendations 1068 10. Added recommendation that routers implement Section 7.3 and 7.5 1069 of RFC 3775. 1070 11. Added pointer to subnet clarification document (RFC 5942). 1071 12. Added text that "IPv6 Host-to-Router Load Sharing" [RFC4311] 1072 SHOULD be implemented 1074 13. Added reference to RFC5722 (Overlapping Fragments), made it a 1075 MUST to implement. 1076 14. Made "A Recommendation for IPv6 Address Text Representation" 1077 [RFC5952] a SHOULD. 1078 15. Removed mention of "DNAME" from the discussion about RFC-3363. 1079 16. Numerous updates to reflect newer versions of IPv6 documents, 1080 including 4443, 4291, 3596, 4213. 1081 17. Removed discussion of "Managed" and "Other" flags in RAs. There 1082 is no consensus at present on how to process these flags and 1083 discussion of their semantics was removed in the most recent 1084 update of Stateless Address Autoconfiguration (RFC 4862). 1085 18. Added many more references to optional IPv6 documents. 1086 19. Made "A Recommendation for IPv6 Address Text Representation" 1087 [RFC5952] a SHOULD. 1088 20. Added reference to RFC5722 (Overlapping Fragments), made it a 1089 MUST to implement. 1090 21. Updated MLD section to include reference to Lightweight MLD 1091 [RFC5790] 1092 22. Added SHOULD recommendation for "Default Router Preferences and 1093 More-Specific Routes" [RFC4191]. 1095 19. References 1097 19.1. Normative References 1099 [RFC1034] Mockapetris, P., "Domain names - concepts and facilities", 1100 STD 13, RFC 1034, November 1987. 1102 [RFC1035] Mockapetris, P., "Domain names - implementation and 1103 specification", STD 13, RFC 1035, November 1987. 1105 [RFC1981] McCann, J., Deering, S., and J. Mogul, "Path MTU Discovery 1106 for IP version 6", RFC 1981, August 1996. 1108 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1109 Requirement Levels", BCP 14, RFC 2119, March 1997. 1111 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 1112 (IPv6) Specification", RFC 2460, December 1998. 1114 [RFC2671] Vixie, P., "Extension Mechanisms for DNS (EDNS0)", 1115 RFC 2671, August 1999. 1117 [RFC2710] Deering, S., Fenner, W., and B. Haberman, "Multicast 1118 Listener Discovery (MLD) for IPv6", RFC 2710, 1119 October 1999. 1121 [RFC2711] Partridge, C. and A. Jackson, "IPv6 Router Alert Option", 1122 RFC 2711, October 1999. 1124 [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., 1125 and M. Carney, "Dynamic Host Configuration Protocol for 1126 IPv6 (DHCPv6)", RFC 3315, July 2003. 1128 [RFC3484] Draves, R., "Default Address Selection for Internet 1129 Protocol version 6 (IPv6)", RFC 3484, February 2003. 1131 [RFC3590] Haberman, B., "Source Address Selection for the Multicast 1132 Listener Discovery (MLD) Protocol", RFC 3590, 1133 September 2003. 1135 [RFC3596] Thomson, S., Huitema, C., Ksinant, V., and M. Souissi, 1136 "DNS Extensions to Support IP Version 6", RFC 3596, 1137 October 2003. 1139 [RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol 1140 (DHCP) Service for IPv6", RFC 3736, April 2004. 1142 [RFC3810] Vida, R. and L. Costa, "Multicast Listener Discovery 1143 Version 2 (MLDv2) for IPv6", RFC 3810, June 2004. 1145 [RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S. 1146 Rose, "DNS Security Introduction and Requirements", 1147 RFC 4033, March 2005. 1149 [RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S. 1150 Rose, "Resource Records for the DNS Security Extensions", 1151 RFC 4034, March 2005. 1153 [RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S. 1154 Rose, "Protocol Modifications for the DNS Security 1155 Extensions", RFC 4035, March 2005. 1157 [RFC4213] Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms 1158 for IPv6 Hosts and Routers", RFC 4213, October 2005. 1160 [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing 1161 Architecture", RFC 4291, February 2006. 1163 [RFC4292] Haberman, B., "IP Forwarding Table MIB", RFC 4292, 1164 April 2006. 1166 [RFC4293] Routhier, S., "Management Information Base for the 1167 Internet Protocol (IP)", RFC 4293, April 2006. 1169 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 1170 Internet Protocol", RFC 4301, December 2005. 1172 [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", 1173 RFC 4303, December 2005. 1175 [RFC4307] Schiller, J., "Cryptographic Algorithms for Use in the 1176 Internet Key Exchange Version 2 (IKEv2)", RFC 4307, 1177 December 2005. 1179 [RFC4311] Hinden, R. and D. Thaler, "IPv6 Host-to-Router Load 1180 Sharing", RFC 4311, November 2005. 1182 [RFC4443] Conta, A., Deering, S., and M. Gupta, "Internet Control 1183 Message Protocol (ICMPv6) for the Internet Protocol 1184 Version 6 (IPv6) Specification", RFC 4443, March 2006. 1186 [RFC4604] Holbrook, H., Cain, B., and B. Haberman, "Using Internet 1187 Group Management Protocol Version 3 (IGMPv3) and Multicast 1188 Listener Discovery Protocol Version 2 (MLDv2) for Source- 1189 Specific Multicast", RFC 4604, August 2006. 1191 [RFC4607] Holbrook, H. and B. Cain, "Source-Specific Multicast for 1192 IP", RFC 4607, August 2006. 1194 [RFC4835] Manral, V., "Cryptographic Algorithm Implementation 1195 Requirements for Encapsulating Security Payload (ESP) and 1196 Authentication Header (AH)", RFC 4835, April 2007. 1198 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 1199 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 1200 September 2007. 1202 [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless 1203 Address Autoconfiguration", RFC 4862, September 2007. 1205 [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy 1206 Extensions for Stateless Address Autoconfiguration in 1207 IPv6", RFC 4941, September 2007. 1209 [RFC5095] Abley, J., Savola, P., and G. Neville-Neil, "Deprecation 1210 of Type 0 Routing Headers in IPv6", RFC 5095, 1211 December 2007. 1213 [RFC5453] Krishnan, S., "Reserved IPv6 Interface Identifiers", 1214 RFC 5453, February 2009. 1216 [RFC5722] Krishnan, S., "Handling of Overlapping IPv6 Fragments", 1217 RFC 5722, December 2009. 1219 [RFC5790] Liu, H., Cao, W., and H. Asaeda, "Lightweight Internet 1220 Group Management Protocol Version 3 (IGMPv3) and Multicast 1221 Listener Discovery Version 2 (MLDv2) Protocols", RFC 5790, 1222 February 2010. 1224 [RFC5942] Singh, H., Beebee, W., and E. Nordmark, "IPv6 Subnet 1225 Model: The Relationship between Links and Subnet 1226 Prefixes", RFC 5942, July 2010. 1228 [RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6 1229 Address Text Representation", RFC 5952, August 2010. 1231 [RFC5996] Kaufman, C., Hoffman, P., Nir, Y., and P. Eronen, 1232 "Internet Key Exchange Protocol Version 2 (IKEv2)", 1233 RFC 5996, September 2010. 1235 [RFC6106] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli, 1236 "IPv6 Router Advertisement Options for DNS Configuration", 1237 RFC 6106, November 2010. 1239 [RFC6204] Singh, H., Beebee, W., Donley, C., Stark, B., and O. 1240 Troan, "Basic Requirements for IPv6 Customer Edge 1241 Routers", RFC 6204, April 2011. 1243 19.2. Informative References 1245 [DODv6] DISR IPv6 Standards Technical Working Group, "DoD IPv6 1246 Standard Profiles For IPv6 Capable Products Version 5.0", 1247 July 2010, 1248 . 1250 [POSIX] IEEE, "IEEE Std. 1003.1-2001 Standard for Information 1251 Technology -- Portable Operating System Interface (POSIX), 1252 ISO/IEC 9945:2002", December 2001, 1253 . 1255 [RFC0793] Postel, J., "Transmission Control Protocol", STD 7, 1256 RFC 793, September 1981. 1258 [RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. 1259 Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 1260 Functional Specification", RFC 2205, September 1997. 1262 [RFC2429] Bormann, C., Cline, L., Deisher, G., Gardos, T., Maciocco, 1263 C., Newell, D., Ott, J., Sullivan, G., Wenger, S., and C. 1264 Zhu, "RTP Payload Format for the 1998 Version of ITU-T 1265 Rec. H.263 Video (H.263+)", RFC 2429, October 1998. 1267 [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet 1268 Networks", RFC 2464, December 1998. 1270 [RFC2492] Armitage, G., Schulter, P., and M. Jork, "IPv6 over ATM 1271 Networks", RFC 2492, January 1999. 1273 [RFC2590] Conta, A., Malis, A., and M. Mueller, "Transmission of 1274 IPv6 Packets over Frame Relay Networks Specification", 1275 RFC 2590, May 1999. 1277 [RFC2675] Borman, D., Deering, S., and R. Hinden, "IPv6 Jumbograms", 1278 RFC 2675, August 1999. 1280 [RFC3146] Fujisawa, K. and A. Onoe, "Transmission of IPv6 Packets 1281 over IEEE 1394 Networks", RFC 3146, October 2001. 1283 [RFC3363] Bush, R., Durand, A., Fink, B., Gudmundsson, O., and T. 1284 Hain, "Representing Internet Protocol version 6 (IPv6) 1285 Addresses in the Domain Name System (DNS)", RFC 3363, 1286 August 2002. 1288 [RFC3493] Gilligan, R., Thomson, S., Bound, J., McCann, J., and W. 1289 Stevens, "Basic Socket Interface Extensions for IPv6", 1290 RFC 3493, February 2003. 1292 [RFC3542] Stevens, W., Thomas, M., Nordmark, E., and T. Jinmei, 1293 "Advanced Sockets Application Program Interface (API) for 1294 IPv6", RFC 3542, May 2003. 1296 [RFC3678] Thaler, D., Fenner, B., and B. Quinn, "Socket Interface 1297 Extensions for Multicast Source Filters", RFC 3678, 1298 January 2004. 1300 [RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support 1301 in IPv6", RFC 3775, June 2004. 1303 [RFC3776] Arkko, J., Devarapalli, V., and F. Dupont, "Using IPsec to 1304 Protect Mobile IPv6 Signaling Between Mobile Nodes and 1305 Home Agents", RFC 3776, June 2004. 1307 [RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure 1308 Neighbor Discovery (SEND)", RFC 3971, March 2005. 1310 [RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)", 1311 RFC 3972, March 2005. 1313 [RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and 1314 More-Specific Routes", RFC 4191, November 2005. 1316 [RFC4302] Kent, S., "IP Authentication Header", RFC 4302, 1317 December 2005. 1319 [RFC4338] DeSanti, C., Carlson, C., and R. Nixon, "Transmission of 1320 IPv6, IPv4, and Address Resolution Protocol (ARP) Packets 1321 over Fibre Channel", RFC 4338, January 2006. 1323 [RFC4380] Huitema, C., "Teredo: Tunneling IPv6 over UDP through 1324 Network Address Translations (NATs)", RFC 4380, 1325 February 2006. 1327 [RFC4429] Moore, N., "Optimistic Duplicate Address Detection (DAD) 1328 for IPv6", RFC 4429, April 2006. 1330 [RFC4584] Chakrabarti, S. and E. Nordmark, "Extension to Sockets API 1331 for Mobile IPv6", RFC 4584, July 2006. 1333 [RFC4821] Mathis, M. and J. Heffner, "Packetization Layer Path MTU 1334 Discovery", RFC 4821, March 2007. 1336 [RFC4877] Devarapalli, V. and F. Dupont, "Mobile IPv6 Operation with 1337 IKEv2 and the Revised IPsec Architecture", RFC 4877, 1338 April 2007. 1340 [RFC4884] Bonica, R., Gan, D., Tappan, D., and C. Pignataro, 1341 "Extended ICMP to Support Multi-Part Messages", RFC 4884, 1342 April 2007. 1344 [RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler, 1345 "Transmission of IPv6 Packets over IEEE 802.15.4 1346 Networks", RFC 4944, September 2007. 1348 [RFC5006] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli, 1349 "IPv6 Router Advertisement Option for DNS Configuration", 1350 RFC 5006, September 2007. 1352 [RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6 1353 Socket API for Source Address Selection", RFC 5014, 1354 September 2007. 1356 [RFC5072] S.Varada, Haskins, D., and E. Allen, "IP Version 6 over 1357 PPP", RFC 5072, September 2007. 1359 [RFC5121] Patil, B., Xia, F., Sarikaya, B., Choi, JH., and S. 1360 Madanapalli, "Transmission of IPv6 via the IPv6 1361 Convergence Sublayer over IEEE 802.16 Networks", RFC 5121, 1362 February 2008. 1364 [RFC5555] Soliman, H., "Mobile IPv6 Support for Dual Stack Hosts and 1365 Routers", RFC 5555, June 2009. 1367 [USGv6] National Institute of Standards and Technology, "A Profile 1368 for IPv6 in the U.S. Government - Version 1.0", July 2008, 1369 . 1371 Authors' Addresses 1373 Ed Jankiewicz 1374 SRI International, Inc. 1375 1161 Broad Street - Suite 212 1376 Shrewsbury, NJ 07702 1377 USA 1379 Phone: 443-502-5815 1380 Email: edward.jankiewicz@sri.com 1382 John Loughney 1383 Nokia 1384 955 Page Mill Road 1385 Palo Alto 94303 1386 USA 1388 Phone: +1 650 283 8068 1389 Email: john.loughney@nokia.com 1391 Thomas Narten 1392 IBM Corporation 1393 3039 Cornwallis Ave. 1394 PO Box 12195 1395 Research Triangle Park, NC 27709-2195 1396 USA 1398 Phone: +1 919 254 7798 1399 Email: narten@us.ibm.com