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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 3315 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 3736 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 4307 (Obsoleted by RFC 8247) ** Obsolete normative reference: RFC 4941 (Obsoleted by RFC 8981) ** Obsolete normative reference: RFC 7223 (Obsoleted by RFC 8343) ** Obsolete normative reference: RFC 7277 (Obsoleted by RFC 8344) ** Obsolete normative reference: RFC 7321 (Obsoleted by RFC 8221) -- Obsolete informational reference (is this intentional?): RFC 793 (Obsoleted by RFC 9293) Summary: 9 errors (**), 0 flaws (~~), 1 warning (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Internet Engineering Task Force T. Chown 3 Internet-Draft Jisc 4 Obsoletes: 6434 (if approved) J. Loughney 5 Intended status: Informational Nokia 6 Expires: January 4, 2018 T. Winters 7 University of New Hampshire 8 July 3, 2017 10 IPv6 Node Requirements 11 draft-ietf-6man-rfc6434-bis-01 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 RFC 6434, and in turn RFC 4294. 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 January 4, 2018. 40 Copyright Notice 42 Copyright (c) 2017 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 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 58 1.1. Scope of This Document . . . . . . . . . . . . . . . . . 4 59 1.2. Description of IPv6 Nodes . . . . . . . . . . . . . . . . 4 60 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 5 61 3. Abbreviations Used in This Document . . . . . . . . . . . . . 5 62 4. Sub-IP Layer . . . . . . . . . . . . . . . . . . . . . . . . 5 63 5. IP Layer . . . . . . . . . . . . . . . . . . . . . . . . . . 6 64 5.1. Internet Protocol Version 6 - RFC 2460 . . . . . . . . . 6 65 5.2. Support for IPv6 Extension Headers . . . . . . . . . . . 7 66 5.3. Neighbor Discovery for IPv6 - RFC 4861 . . . . . . . . . 8 67 5.4. SEcure Neighbor Discovery (SEND) - RFC 3971 . . . . . . . 9 68 5.5. IPv6 Router Advertisement Flags Option - RFC 5175 . . . . 10 69 5.6. Path MTU Discovery and Packet Size . . . . . . . . . . . 10 70 5.6.1. Path MTU Discovery - RFC 1981 . . . . . . . . . . . . 10 71 5.7. IPv6 Jumbograms - RFC 2675 . . . . . . . . . . . . . . . 10 72 5.8. ICMP for the Internet Protocol Version 6 (IPv6) - RFC 73 4443 . . . . . . . . . . . . . . . . . . . . . . . . . . 11 74 5.9. Default Router Preferences and More-Specific Routes - RFC 75 4191 . . . . . . . . . . . . . . . . . . . . . . . . . . 11 76 5.10. First-Hop Router Selection - RFC 8028 . . . . . . . . . . 11 77 5.11. Multicast Listener Discovery (MLD) for IPv6 - RFC 3810 . 11 78 5.12. Explicit Congestion Notification (ECN) - RFC 3168 . . . . 12 79 6. Addressing and Address Configuration . . . . . . . . . . . . 12 80 6.1. IP Version 6 Addressing Architecture - RFC 4291 . . . . . 12 81 6.2. Host Address Availability Recommendations . . . . . . . . 12 82 6.3. IPv6 Stateless Address Autoconfiguration - RFC 4862 . . . 13 83 6.4. Privacy Extensions for Address Configuration in IPv6 - 84 RFC 4941 . . . . . . . . . . . . . . . . . . . . . . . . 14 85 6.5. Stateful Address Autoconfiguration (DHCPv6) - RFC 3315 . 14 86 6.6. Default Address Selection for IPv6 - RFC 6724 . . . . . . 15 87 7. DNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 88 8. Configuring Non-Address Information . . . . . . . . . . . . . 15 89 8.1. DHCP for Other Configuration Information . . . . . . . . 15 90 8.2. Router Advertisements and Default Gateway . . . . . . . . 16 91 8.3. IPv6 Router Advertisement Options for DNS 92 Configuration - RFC 8106 . . . . . . . . . . . . . . . . 16 93 8.4. DHCP Options versus Router Advertisement Options for Host 94 Configuration . . . . . . . . . . . . . . . . . . . . . . 16 95 9. Service Discovery Protocols . . . . . . . . . . . . . . . . . 17 96 10. IPv4 Support and Transition . . . . . . . . . . . . . . . . . 17 97 10.1. Transition Mechanisms . . . . . . . . . . . . . . . . . 17 98 10.1.1. Basic Transition Mechanisms for IPv6 Hosts and 99 Routers - RFC 4213 . . . . . . . . . . . . . . . . . 17 100 11. Application Support . . . . . . . . . . . . . . . . . . . . . 17 101 11.1. Textual Representation of IPv6 Addresses - RFC 5952 . . 17 102 11.2. Application Programming Interfaces (APIs) . . . . . . . 17 103 12. Mobility . . . . . . . . . . . . . . . . . . . . . . . . . . 18 104 13. Security . . . . . . . . . . . . . . . . . . . . . . . . . . 19 105 13.1. Requirements . . . . . . . . . . . . . . . . . . . . . . 20 106 13.2. Transforms and Algorithms . . . . . . . . . . . . . . . 20 107 14. Router-Specific Functionality . . . . . . . . . . . . . . . . 21 108 14.1. IPv6 Router Alert Option - RFC 2711 . . . . . . . . . . 21 109 14.2. Neighbor Discovery for IPv6 - RFC 4861 . . . . . . . . . 21 110 14.3. Stateful Address Autoconfiguration (DHCPv6) - RFC 3315 . 21 111 15. Constrained Devices . . . . . . . . . . . . . . . . . . . . . 22 112 16. Network Management . . . . . . . . . . . . . . . . . . . . . 22 113 16.1. Management Information Base (MIB) Modules . . . . . . . 22 114 16.1.1. IP Forwarding Table MIB . . . . . . . . . . . . . . 23 115 16.1.2. Management Information Base for the Internet 116 Protocol (IP) . . . . . . . . . . . . . . . . . . . 23 117 16.2. YANG Data Models . . . . . . . . . . . . . . . . . . . . 23 118 16.2.1. IP Management YANG Model . . . . . . . . . . . . . . 23 119 16.2.2. System Management YANG Model . . . . . . . . . . . . 23 120 16.2.3. System Management YANG Model . . . . . . . . . . . . 23 121 17. Security Considerations . . . . . . . . . . . . . . . . . . . 23 122 18. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 123 19. Authors and Acknowledgments . . . . . . . . . . . . . . . . . 23 124 19.1. Authors and Acknowledgments (Current Document) . . . . . 24 125 19.2. Authors and Acknowledgments from RFC 6434 . . . . . . . 24 126 19.3. Authors and Acknowledgments from RFC 4294 . . . . . . . 24 127 20. Appendix: Changes from RFC 6434 . . . . . . . . . . . . . . . 26 128 21. Appendix: Changes from RFC 4294 . . . . . . . . . . . . . . . 26 129 22. References . . . . . . . . . . . . . . . . . . . . . . . . . 28 130 22.1. Normative References . . . . . . . . . . . . . . . . . . 28 131 22.2. Informative References . . . . . . . . . . . . . . . . . 33 132 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38 134 1. Introduction 136 This document defines common functionality required by both IPv6 137 hosts and routers. Many IPv6 nodes will implement optional or 138 additional features, but this document collects and summarizes 139 requirements from other published Standards Track documents in one 140 place. 142 This document tries to avoid discussion of protocol details and 143 references RFCs for this purpose. This document is intended to be an 144 applicability statement and to provide guidance as to which IPv6 145 specifications should be implemented in the general case and which 146 specifications may be of interest to specific deployment scenarios. 147 This document does not update any individual protocol document RFCs. 149 Although this document points to different specifications, it should 150 be noted that in many cases, the granularity of a particular 151 requirement will be smaller than a single specification, as many 152 specifications define multiple, independent pieces, some of which may 153 not be mandatory. In addition, most specifications define both 154 client and server behavior in the same specification, while many 155 implementations will be focused on only one of those roles. 157 This document defines a minimal level of requirement needed for a 158 device to provide useful internet service and considers a broad range 159 of device types and deployment scenarios. Because of the wide range 160 of deployment scenarios, the minimal requirements specified in this 161 document may not be sufficient for all deployment scenarios. It is 162 perfectly reasonable (and indeed expected) for other profiles to 163 define additional or stricter requirements appropriate for specific 164 usage and deployment environments. For example, this document does 165 not mandate that all clients support DHCP, but some deployment 166 scenarios may deem it appropriate to make such a requirement. For 167 example, government agencies in the USA have defined profiles for 168 specialized requirements for IPv6 in target environments (see 169 [USGv6]). 171 As it is not always possible for an implementer to know the exact 172 usage of IPv6 in a node, an overriding requirement for IPv6 nodes is 173 that they should adhere to Jon Postel's Robustness Principle: "Be 174 conservative in what you do, be liberal in what you accept from 175 others" [RFC0793]. 177 1.1. Scope of This Document 179 IPv6 covers many specifications. It is intended that IPv6 will be 180 deployed in many different situations and environments. Therefore, 181 it is important to develop requirements for IPv6 nodes to ensure 182 interoperability. 184 This document assumes that all IPv6 nodes meet the minimum 185 requirements specified here. 187 1.2. Description of IPv6 Nodes 189 From the Internet Protocol, Version 6 (IPv6) Specification [RFC2460], 190 we have the following definitions: 192 IPv6 node - a device that implements IPv6. 193 IPv6 router - a node that forwards IPv6 packets not explicitly 194 addressed to itself. 195 IPv6 host - any node that is not a router. 197 **BIS We will need to refer to 2460-bis, as well as 1981-bis and 198 4291-bis, throughout this document. These are still in flux, but we 199 will know the final versions of these documents before this -bis is 200 published, so can adapt text here once those updates are complete.** 202 2. Requirements Language 204 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 205 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 206 document are to be interpreted as described in RFC 2119 [RFC2119]. 208 3. Abbreviations Used in This Document 210 ATM Asynchronous Transfer Mode 211 AH Authentication Header 212 DAD Duplicate Address Detection 213 ESP Encapsulating Security Payload 214 ICMP Internet Control Message Protocol 215 IKE Internet Key Exchange 216 MIB Management Information Base 217 MLD Multicast Listener Discovery 218 MTU Maximum Transmission Unit 219 NA Neighbor Advertisement 220 NBMA Non-Broadcast Multiple Access 221 ND Neighbor Discovery 222 NS Neighbor Solicitation 223 NUD Neighbor Unreachability Detection 224 PPP Point-to-Point Protocol 226 4. Sub-IP Layer 228 An IPv6 node must include support for one or more IPv6 link-layer 229 specifications. Which link-layer specifications an implementation 230 should include will depend upon what link-layers are supported by the 231 hardware available on the system. It is possible for a conformant 232 IPv6 node to support IPv6 on some of its interfaces and not on 233 others. 235 As IPv6 is run over new layer 2 technologies, it is expected that new 236 specifications will be issued. In the following, we list some of the 237 layer 2 technologies for which an IPv6 specification has been 238 developed. It is provided for informational purposes only and may 239 not be complete. 241 - Transmission of IPv6 Packets over Ethernet Networks [RFC2464] 243 - IPv6 over ATM Networks [RFC2492] 245 - Transmission of IPv6 Packets over Frame Relay Networks 246 Specification [RFC2590] 248 - Transmission of IPv6 Packets over IEEE 1394 Networks [RFC3146] 250 - Transmission of IPv6, IPv4, and Address Resolution Protocol (ARP) 251 Packets over Fibre Channel [RFC4338] 253 - Transmission of IPv6 Packets over IEEE 802.15.4 Networks [RFC4944] 255 - Transmission of IPv6 via the IPv6 Convergence Sublayer over IEEE 256 802.16 Networks [RFC5121] 258 - IP version 6 over PPP [RFC5072] 260 In addition to traditional physical link-layers, it is also possible 261 to tunnel IPv6 over other protocols. Examples include: 263 - Teredo: Tunneling IPv6 over UDP through Network Address 264 Translations (NATs) [RFC4380] 266 - Section 3 of "Basic Transition Mechanisms for IPv6 Hosts and 267 Routers" [RFC4213] 269 **BIS Do we want a small section somewhere on UDP IPv6 tunneling, and 270 issues like RFC 6935, or 6936?** 272 5. IP Layer 274 5.1. Internet Protocol Version 6 - RFC 2460 276 The Internet Protocol Version 6 is specified in [RFC2460]. This 277 specification MUST be supported. 279 **BIS Again, update for RFC 2460 -bis ** 281 Any unrecognized extension headers or options MUST be processed as 282 described in RFC 2460. 284 The node MUST follow the packet transmission rules in RFC 2460. 286 Nodes MUST always be able to send, receive, and process fragment 287 headers. All conformant IPv6 implementations MUST be capable of 288 sending and receiving IPv6 packets; the forwarding functionality MAY 289 be supported. Overlapping fragments MUST be handled as described in 290 [RFC5722]. 292 [RFC6946] discusses IPv6 atomic fragments, and recommends that IPv6 293 atomic fragments are processed independently of any other fragments, 294 to protect against fragmentation-based attacks. [RFC8021] goes 295 further and recommends the deprecation of atomic fragments. Nodes 296 thus MUST NOT generate atomic fragments. 298 To mitigate a variety of potential attacks, nodes SHOULD avoid using 299 predictable fragment Identification values in Fragment Headers, as 300 discussed in [RFC7739]. 302 All nodes SHOULD support the setting and use of the IPv6 Flow Label 303 field as defined in the IPv6 Flow Label specification [RFC6437]. 304 Forwarding nodes such as routers and load distributors MUST NOT 305 depend only on Flow Label values being uniformly distributed. It is 306 RECOMMENDED that source hosts support the flow label by setting the 307 Flow Label field for all packets of a given flow to the same value 308 chosen from an approximation to a discrete uniform distribution. 310 5.2. Support for IPv6 Extension Headers 312 RFC 2460 specifies extension headers and the processing for these 313 headers. 315 An IPv6 node MUST be able to process these headers. An exception is 316 Routing Header type 0 (RH0), which was deprecated by [RFC5095] due to 317 security concerns and which MUST be treated as an unrecognized 318 routing type. 320 Further, [RFC7045] adds specific requirements for processing of 321 Extension Headers, in particular that any forwarding node along an 322 IPv6 packet's path, which forwards the packet for any reason, SHOULD 323 do so regardless of any extension headers that are present. 325 [RFC7112] discusses issues with oversized IPv6 Extension Header 326 chains, and states that when a node fragments an IPv6 datagram, it 327 MUST include the entire IPv6 Header Chain in the First Fragment. 329 As stated in RFC2460, extension headers (except for the Hop-by-Hop 330 Options header) are not processed, inserted, or deleted by any node 331 along a packet's delivery path, until the packet reaches the node (or 332 each of the set of nodes, in the case of multicast) identified in the 333 Destination Address field of the IPv6 header. 335 Should a new type of Extension Header need to be defined, its format 336 MUST follow the consistent format described in Section 4 of 337 [RFC6564]. 339 ** BIS add text on host side processing of IPv6 EHs. From list 340 discussion about protecting receiver from excessive EH options/pads/ 341 etc. 343 5.3. Neighbor Discovery for IPv6 - RFC 4861 345 Neighbor Discovery is defined in [RFC4861]; the definition was 346 updated by [RFC5942]. Neighbor Discovery SHOULD be supported. RFC 347 4861 states: 349 Unless specified otherwise (in a document that covers operating IP 350 over a particular link type) this document applies to all link 351 types. However, because ND uses link-layer multicast for some of 352 its services, it is possible that on some link types (e.g., Non- 353 Broadcast Multi-Access (NBMA) links), alternative protocols or 354 mechanisms to implement those services will be specified (in the 355 appropriate document covering the operation of IP over a 356 particular link type). The services described in this document 357 that are not directly dependent on multicast, such as Redirects, 358 next-hop determination, Neighbor Unreachability Detection, etc., 359 are expected to be provided as specified in this document. The 360 details of how one uses ND on NBMA links are addressed in 361 [RFC2491]. 363 Some detailed analysis of Neighbor Discovery follows: 365 Router Discovery is how hosts locate routers that reside on an 366 attached link. Hosts MUST support Router Discovery functionality. 368 Prefix Discovery is how hosts discover the set of address prefixes 369 that define which destinations are on-link for an attached link. 370 Hosts MUST support Prefix Discovery. 372 Hosts MUST also implement Neighbor Unreachability Detection (NUD) for 373 all paths between hosts and neighboring nodes. NUD is not required 374 for paths between routers. However, all nodes MUST respond to 375 unicast Neighbor Solicitation (NS) messages. 377 [RFC7048] discusses NUD, in particular cases where it behaves too 378 impatiently. It states that if a node transmits more than a certain 379 number of packets, then it SHOULD use the exponential backoff of the 380 retransmit timer, up to a certain threshold point. 382 Hosts MUST support the sending of Router Solicitations and the 383 receiving of Router Advertisements. The ability to understand 384 individual Router Advertisement options is dependent on supporting 385 the functionality making use of the particular option. 387 [RFC7559] discusses packet loss resliency for Router Solicitations, 388 and requires that nodes MUST use a specific exponential backoff 389 algorithm for RS retransmissions. 391 All nodes MUST support the sending and receiving of Neighbor 392 Solicitation (NS) and Neighbor Advertisement (NA) messages. NS and 393 NA messages are required for Duplicate Address Detection (DAD). 395 Hosts SHOULD support the processing of Redirect functionality. 396 Routers MUST support the sending of Redirects, though not necessarily 397 for every individual packet (e.g., due to rate limiting). Redirects 398 are only useful on networks supporting hosts. In core networks 399 dominated by routers, Redirects are typically disabled. The sending 400 of Redirects SHOULD be disabled by default on backbone routers. They 401 MAY be enabled by default on routers intended to support hosts on 402 edge networks. 404 "IPv6 Host-to-Router Load Sharing" [RFC4311] includes additional 405 recommendations on how to select from a set of available routers. 406 [RFC4311] SHOULD be supported. 408 5.4. SEcure Neighbor Discovery (SEND) - RFC 3971 410 SEND [RFC3971] and Cryptographically Generated Addresses (CGAs) 411 [RFC3972] provide a way to secure the message exchanges of Neighbor 412 Discovery. SEND has the potential to address certain classes of 413 spoofing attacks, but it does not provide specific protection for 414 threats from off-link attackers. It requires relatively heavyweight 415 provisioning, so is only likely to be used in scenarios where 416 security considerations are particularly important. 418 There have been relatively few implementations of SEND in common 419 operating systems and platforms, and thus deployment experience has 420 been limited to date. 422 At this time, SEND is considered optional. Due to the complexity in 423 deploying SEND, its deployment is only likely to be considered where 424 nodes are operating in a particularly strict security environment. 426 5.5. IPv6 Router Advertisement Flags Option - RFC 5175 428 Router Advertisements include an 8-bit field of single-bit Router 429 Advertisement flags. The Router Advertisement Flags Option extends 430 the number of available flag bits by 48 bits. At the time of this 431 writing, 6 of the original 8 single-bit flags have been assigned, 432 while 2 remain available for future assignment. No flags have been 433 defined that make use of the new option, and thus, strictly speaking, 434 there is no requirement to implement the option today. However, 435 implementations that are able to pass unrecognized options to a 436 higher-level entity that may be able to understand them (e.g., a 437 user-level process using a "raw socket" facility) MAY take steps to 438 handle the option in anticipation of a future usage. 440 5.6. Path MTU Discovery and Packet Size 442 5.6.1. Path MTU Discovery - RFC 1981 444 "Path MTU Discovery for IP version 6" [RFC1981] SHOULD be supported. 445 From [RFC2460]: 447 It is strongly recommended that IPv6 nodes implement Path MTU 448 Discovery [RFC1981], in order to discover and take advantage of 449 path MTUs greater than 1280 octets. However, a minimal IPv6 450 implementation (e.g., in a boot ROM) may simply restrict itself to 451 sending packets no larger than 1280 octets, and omit 452 implementation of Path MTU Discovery. 454 The rules in [RFC2460] and [RFC5722] MUST be followed for packet 455 fragmentation and reassembly. 457 One operational issue with Path MTU Discovery occurs when firewalls 458 block ICMP Packet Too Big messages. Path MTU Discovery relies on 459 such messages to determine what size messages can be successfully 460 sent. "Packetization Layer Path MTU Discovery" [RFC4821] avoids 461 having a dependency on Packet Too Big messages. 463 **BIS Add note about 1280 MTU and UDP, as per Mark Andrews' comments 464 in Berlin? ** 466 5.7. IPv6 Jumbograms - RFC 2675 468 IPv6 Jumbograms [RFC2675] are an optional extension that allow the 469 sending of IP datagrams larger than 65,535 bytes. IPv6 Jumbograms 470 make use of IPv6 hop-by-hop options and are only suitable on paths in 471 which every hop and link are capable of supporting Jumbograms (e.g., 472 within a campus or datacenter). To date, few implementations exist, 473 and there is essentially no reported experience from usage. 474 Consequently, IPv6 Jumbograms [RFC2675] remain optional at this time. 476 **BIS Are these used? Do we need to modify the text for that? ** 478 5.8. ICMP for the Internet Protocol Version 6 (IPv6) - RFC 4443 480 ICMPv6 [RFC4443] MUST be supported. "Extended ICMP to Support Multi- 481 Part Messages" [RFC4884] MAY be supported. 483 5.9. Default Router Preferences and More-Specific Routes - RFC 4191 485 "Default Router Preferences and More-Specific Routes" [RFC4191] 486 provides support for nodes attached to multiple (different) networks, 487 each providing routers that advertise themselves as default routers 488 via Router Advertisements. In some scenarios, one router may provide 489 connectivity to destinations the other router does not, and choosing 490 the "wrong" default router can result in reachability failures. In 491 such cases, RFC 4191 can help. 493 Small Office/Home Office (SOHO) deployments supported by routers 494 adhering to [RFC7084] use RFC 4191 to advertise routes to certain 495 local destinations. Consequently, nodes that will be deployed in 496 SOHO environments SHOULD implement RFC 4191. 498 5.10. First-Hop Router Selection - RFC 8028 500 In multihomed scenarios, where a host has more than one prefix, each 501 allocated by an upstream network that is assumed to implement BCP 38 502 ingress filtering, the host may have multiple routers to choose from. 504 Hosts that may be deployed in such multihomed environments SHOULD 505 follow the guidance given in [RFC8028]. 507 5.11. Multicast Listener Discovery (MLD) for IPv6 - RFC 3810 509 Nodes that need to join multicast groups MUST support MLDv2 510 [RFC3810]. MLD is needed by any node that is expected to receive and 511 process multicast traffic and in particular MLDv2 is required for 512 support for source-specific multicast (SSM) as per [RFC4607]. 514 Previous version of this document only required MLDv1 to be 515 implemented on all nodes. Since participation of any MLDv1-only 516 nodes on a link require that all other nodeas on the link then 517 operate in version 1 compatibility mode, the requirement to support 518 MLDv2 on all nodes was upgraded to a MUST. Further, SSM is now the 519 preferred multicast distribution method, rather than ASM. 521 Note that Neighbor Discovery (as used on most link types -- see 522 Section 5.3) depends on multicast and requires that nodes join 523 Solicited Node multicast addresses. 525 5.12. Explicit Congestion Notification (ECN) - RFC 3168 527 An ECN-aware router may set a mark in the IP header instead of 528 dropping a packet in order to signal impending congestion. The 529 receiver of the packet echoes the congestion indication to the 530 sender, which can then reduce its transmission rate as if it detected 531 a dropped packet. 533 Nodes that may be deployed in environments where they would benefit 534 from such early congestion notification SHOULD implement [RFC3168]. 536 ** BIS - but note draft-ietf-tsvwg-ecn-experimentation-03, e.g., 537 nonce comment 539 6. Addressing and Address Configuration 541 6.1. IP Version 6 Addressing Architecture - RFC 4291 543 The IPv6 Addressing Architecture [RFC4291] MUST be supported. 545 **BIS Update to 4291-bis ** 547 **BIS Add note on Why /64? RFC 7421, after the conclusion of the 548 RFC4291-bis (lengthy!!!) discussions on the 64-bit IID topic. But no 549 need for /127 p2p text RFC 6164. And no need for note on IID 550 significance, as per RFC 7136. ** 552 6.2. Host Address Availability Recommendations 554 Hosts may be configured with addresses through a variety of methods, 555 including SLAAC, DHCPv6, or manual configuration. 557 [RFC7934] recommends that networks provide general-purpose end hosts 558 with multiple global IPv6 addresses when they attach, and it 559 describes the benefits of and the options for doing so. There are, 560 for example, benefits to multiple addresses for privacy reasons, or 561 to assigning hosts a whole /64 to avoid the need for host-based NAT. 563 **BIS could add a reference to draft-ietf-v6ops-unique-ipv6-prefix- 564 per-host-06 as a BCP? 566 6.3. IPv6 Stateless Address Autoconfiguration - RFC 4862 568 Hosts MUST support IPv6 Stateless Address Autoconfiguration as 569 defined in either [RFC4862] or [RFC7217]. It is recommended that, 570 unless there is a specific requirement for MAC addresses to be 571 embedded in an IID, nodes follow the procedure in RFC7217 to generate 572 SLAAC-based addresses. Addresses generated through RFC7217 will be 573 the same whenever a given device (re)appears on the same subnet (with 574 a specific IPv6 prefix), but the IID will vary on each subnet 575 visited. 577 Nodes that are routers MUST be able to generate link-local addresses 578 as described in [RFC4862]. 580 From RFC 4862: 582 The autoconfiguration process specified in this document applies 583 only to hosts and not routers. Since host autoconfiguration uses 584 information advertised by routers, routers will need to be 585 configured by some other means. However, it is expected that 586 routers will generate link-local addresses using the mechanism 587 described in this document. In addition, routers are expected to 588 successfully pass the Duplicate Address Detection procedure 589 described in this document on all addresses prior to assigning 590 them to an interface. 592 All nodes MUST implement Duplicate Address Detection. Quoting from 593 Section 5.4 of RFC 4862: 595 Duplicate Address Detection MUST be performed on all unicast 596 addresses prior to assigning them to an interface, regardless of 597 whether they are obtained through stateless autoconfiguration, 598 DHCPv6, or manual configuration, with the following [exceptions 599 noted therein]. 601 "Optimistic Duplicate Address Detection (DAD) for IPv6" [RFC4429] 602 specifies a mechanism to reduce delays associated with generating 603 addresses via Stateless Address Autoconfiguration [RFC4862]. RFC 604 4429 was developed in conjunction with Mobile IPv6 in order to reduce 605 the time needed to acquire and configure addresses as devices quickly 606 move from one network to another, and it is desirable to minimize 607 transition delays. For general purpose devices, RFC 4429 remains 608 optional at this time. 610 [RFC7527] discusses enhanced DAD, and describes an algorithm to 611 automate the detection of looped back IPv6 ND messages used by DAD. 612 Nodes SHOULD implement this behaviour where such detection is 613 beneficial. 615 6.4. Privacy Extensions for Address Configuration in IPv6 - RFC 4941 617 A node using Stateless Address Autoconfiguration [RFC4862] to form a 618 globally unique IPv6 address using its MAC address to generate the 619 IID will see that IID remain the same on any visited network, even 620 though the network prefix part changes. Thus it is possible for 3rd 621 party devices such nodes communicate with to track the activities of 622 the node as it moves around the network. Privacy Extensions for 623 Stateless Address Autoconfiguration [RFC4941] address this concern by 624 allowing nodes to configure an additional temporary address where the 625 IID is effectively randomly generated. Privacy addresses are then 626 used as source addresses for new communications initiated by the 627 node. 629 [RFC7721] discusses general privacy issues with IPv6 addressing. 631 RFC 4941 SHOULD be supported. In some scenarios, such as dedicated 632 servers in a data center, it provides limited or no benefit, or may 633 complicate network management. Thus devices implementing this 634 specification MUST provide a way for the end user to explicitly 635 enable or disable the use of such temporary addresses. 637 Note that RFC4941 can be used independently of traditional SLAAC, or 638 of RFC7217-based SLAAC. 640 Implementers of RFC 4941 should be aware that certain addresses are 641 reserved and should not be chosen for use as temporary addresses. 642 Consult "Reserved IPv6 Interface Identifiers" [RFC5453] for more 643 details. 645 6.5. Stateful Address Autoconfiguration (DHCPv6) - RFC 3315 647 DHCPv6 [RFC3315] can be used to obtain and configure addresses. In 648 general, a network may provide for the configuration of addresses 649 through Router Advertisements, DHCPv6, or both. There will be a wide 650 range of IPv6 deployment models and differences in address assignment 651 requirements, some of which may require DHCPv6 for stateful address 652 assignment. Consequently, all hosts SHOULD implement address 653 configuration via DHCPv6. 655 In the absence of a router, IPv6 nodes using DHCP for address 656 assignment MAY initiate DHCP to obtain IPv6 addresses and other 657 configuration information, as described in Section 5.5.2 of 658 [RFC4862]. 660 Where devices are likely to be carried by users and attached to 661 multiple visisted networks, DHCPv6 client anonymity profiles SHOULD 662 be supported as described in [RFC7844] to minimise the discolosure of 663 identifying information. 665 6.6. Default Address Selection for IPv6 - RFC 6724 667 IPv6 nodes will invariably have multiple addresses configured 668 simultaneously, and thus will need to choose which addresses to use 669 for which communications. The rules specified in the Default Address 670 Selection for IPv6 [RFC6724] document MUST be implemented. 672 7. DNS 674 DNS is described in [RFC1034], [RFC1035], [RFC3363], and [RFC3596]. 675 Not all nodes will need to resolve names; those that will never need 676 to resolve DNS names do not need to implement resolver functionality. 677 However, the ability to resolve names is a basic infrastructure 678 capability on which applications rely, and most nodes will need to 679 provide support. All nodes SHOULD implement stub-resolver [RFC1034] 680 functionality, as in [RFC1034], Section 5.3.1, with support for: 682 - AAAA type Resource Records [RFC3596]; 684 - reverse addressing in ip6.arpa using PTR records [RFC3596]; 686 - Extension Mechanisms for DNS (EDNS0) [RFC6891] to allow for DNS 687 packet sizes larger than 512 octets. 689 Those nodes are RECOMMENDED to support DNS security extensions 690 [RFC4033] [RFC4034] [RFC4035]. 692 A6 Resource Records, which were only ever defined with Experimental 693 status in [RFC3363], are now classified as Historic, as per 694 [RFC6563]. 696 8. Configuring Non-Address Information 698 8.1. DHCP for Other Configuration Information 700 IPv6 nodes use DHCP [RFC3315] to obtain address configuration 701 information (see Section 6.5) and to obtain additional (non-address) 702 configuration. If a host implementation supports applications or 703 other protocols that require configuration that is only available via 704 DHCP, hosts SHOULD implement DHCP. For specialized devices on which 705 no such configuration need is present, DHCP may not be necessary. 707 An IPv6 node can use the subset of DHCP (described in [RFC3736]) to 708 obtain other configuration information. 710 8.2. Router Advertisements and Default Gateway 712 There is no defined DHCPv6 Gateway option. 714 Nodes using the Dynamic Host Configuration Protocol for IPv6 (DHCPv6) 715 are thus expected to determine their default router information and 716 on-link prefix information from received Router Advertisements. 718 8.3. IPv6 Router Advertisement Options for DNS Configuration - RFC 8106 720 Router Advertisements have historically limited options to those that 721 are critical to basic IPv6 functioning. Originally, DNS 722 configuration was not included as an RA option, and DHCP was the 723 recommended way to obtain DNS configuration information. Over time, 724 the thinking surrounding such an option has evolved. It is now 725 generally recognized that few nodes can function adequately without 726 having access to a working DNS resolver, and thus a Standards Track 727 document has been published to provide this capability [RFC8106]. 729 Implementations MUST include support for the DNS RA option [RFC8106]. 731 8.4. DHCP Options versus Router Advertisement Options for Host 732 Configuration 734 **BIS needs rewriting 736 In IPv6, there are two main protocol mechanisms for propagating 737 configuration information to hosts: Router Advertisements (RAs) and 738 DHCP. Historically, RA options have been restricted to those deemed 739 essential for basic network functioning and for which all nodes are 740 configured with exactly the same information. Examples include the 741 Prefix Information Options, the MTU option, etc. On the other hand, 742 DHCP has generally been preferred for configuration of more general 743 parameters and for parameters that may be client-specific. That 744 said, identifying the exact line on whether a particular option 745 should be configured via DHCP versus an RA option has not always been 746 easy. Generally speaking, however, there has been a desire to define 747 only one mechanism for configuring a given option, rather than 748 defining multiple (different) ways of configuring the same 749 information. 751 One issue with having multiple ways of configuring the same 752 information is that interoperability suffers if a host chooses one 753 mechanism but the network operator chooses a different mechanism. 754 For "closed" environments, where the network operator has significant 755 influence over what devices connect to the network and thus what 756 configuration mechanisms they support, the operator may be able to 757 ensure that a particular mechanism is supported by all connected 758 hosts. In more open environments, however, where arbitrary devices 759 may connect (e.g., a WIFI hotspot), problems can arise. To maximize 760 interoperability in such environments, hosts would need to implement 761 multiple configuration mechanisms to ensure interoperability. 763 9. Service Discovery Protocols 765 [RFC6762] and [RFC6763] describe multicast DNS (mDNS) and DNS-Based 766 Service Discovery (DNS-SD) respectively. These protocols, 767 collectively commonly referred to as the 'Bonjour' protocols after 768 their naming by Apple, provide the means for devices to discover 769 services within a local link and, in the absence of a unicast DNS 770 service, to exchange naming information. 772 Where devices are to be deployed in networks where service dicovery 773 would be beneficial, e.g., for users seeking to discover printers or 774 display devices, mDNS and DNS-SD SHOULD be supported. 776 The IETF dnssd WG is defining solutions for DNS-based service 777 discovery in multi-link networks. 779 10. IPv4 Support and Transition 781 IPv6 nodes MAY support IPv4. 783 10.1. Transition Mechanisms 785 10.1.1. Basic Transition Mechanisms for IPv6 Hosts and Routers - RFC 786 4213 788 If an IPv6 node implements dual stack and tunneling, then [RFC4213] 789 MUST be supported. 791 11. Application Support 793 11.1. Textual Representation of IPv6 Addresses - RFC 5952 795 Software that allows users and operators to input IPv6 addresses in 796 text form SHOULD support "A Recommendation for IPv6 Address Text 797 Representation" [RFC5952]. 799 11.2. Application Programming Interfaces (APIs) 801 There are a number of IPv6-related APIs. This document does not 802 mandate the use of any, because the choice of API does not directly 803 relate to on-the-wire behavior of protocols. Implementers, however, 804 would be advised to consider providing a common API or reviewing 805 existing APIs for the type of functionality they provide to 806 applications. 808 "Basic Socket Interface Extensions for IPv6" [RFC3493] provides IPv6 809 functionality used by typical applications. Implementers should note 810 that RFC3493 has been picked up and further standardized by the 811 Portable Operating System Interface (POSIX) [POSIX]. 813 "Advanced Sockets Application Program Interface (API) for IPv6" 814 [RFC3542] provides access to advanced IPv6 features needed by 815 diagnostic and other more specialized applications. 817 "IPv6 Socket API for Source Address Selection" [RFC5014] provides 818 facilities that allow an application to override the default Source 819 Address Selection rules of [RFC6724]. 821 "Socket Interface Extensions for Multicast Source Filters" [RFC3678] 822 provides support for expressing source filters on multicast group 823 memberships. 825 "Extension to Sockets API for Mobile IPv6" [RFC4584] provides 826 application support for accessing and enabling Mobile IPv6 [RFC6275] 827 features. 829 12. Mobility 831 Mobile IPv6 [RFC6275] and associated specifications [RFC3776] 832 [RFC4877] allow a node to change its point of attachment within the 833 Internet, while maintaining (and using) a permanent address. All 834 communication using the permanent address continues to proceed as 835 expected even as the node moves around. The definition of Mobile IP 836 includes requirements for the following types of nodes: 838 - mobile nodes 840 - correspondent nodes with support for route optimization 842 - home agents 844 - all IPv6 routers 846 At the present time, Mobile IP has seen only limited implementation 847 and no significant deployment, partly because it originally assumed 848 an IPv6-only environment rather than a mixed IPv4/IPv6 Internet. 849 Recently, additional work has been done to support mobility in mixed- 850 mode IPv4 and IPv6 networks [RFC5555]. 852 More usage and deployment experience is needed with mobility before 853 any specific approach can be recommended for broad implementation in 854 all hosts and routers. Consequently, [RFC6275], [RFC5555], and 855 associated standards such as [RFC4877] are considered a MAY at this 856 time. 858 IPv6 for 3GPP [RFC7066] lists IPv6 Functionalities that need to be 859 implemented above and beyond the recommendations in this document. 860 Additionally a 3GPP IPv6 Host MAY implement [RFC7278] for delivering 861 IPv6 prefixes on the LAN link. 863 13. Security 865 This section describes the specification for security for IPv6 nodes. 867 Achieving security in practice is a complex undertaking. Operational 868 procedures, protocols, key distribution mechanisms, certificate 869 management approaches, etc., are all components that impact the level 870 of security actually achieved in practice. More importantly, 871 deficiencies or a poor fit in any one individual component can 872 significantly reduce the overall effectiveness of a particular 873 security approach. 875 IPsec provides channel security at the Internet layer, making it 876 possible to provide secure communication for all (or a subset of) 877 communication flows at the IP layer between pairs of internet nodes. 878 IPsec provides sufficient flexibility and granularity that individual 879 TCP connections can (selectively) be protected, etc. 881 Although IPsec can be used with manual keying in some cases, such 882 usage has limited applicability and is not recommended. 884 A range of security technologies and approaches proliferate today 885 (e.g., IPsec, Transport Layer Security (TLS), Secure SHell (SSH), 886 etc.) No one approach has emerged as an ideal technology for all 887 needs and environments. Moreover, IPsec is not viewed as the ideal 888 security technology in all cases and is unlikely to displace the 889 others. 891 Previously, IPv6 mandated implementation of IPsec and recommended the 892 key management approach of IKE. This document updates that 893 recommendation by making support of the IPsec Architecture [RFC4301] 894 a SHOULD for all IPv6 nodes. Note that the IPsec Architecture 895 requires (e.g., Section 4.5 of RFC 4301) the implementation of both 896 manual and automatic key management. Currently, the default 897 automated key management protocol to implement is IKEv2 [RFC7296]. 899 This document recognizes that there exists a range of device types 900 and environments where approaches to security other than IPsec can be 901 justified. For example, special-purpose devices may support only a 902 very limited number or type of applications, and an application- 903 specific security approach may be sufficient for limited management 904 or configuration capabilities. Alternatively, some devices may run 905 on extremely constrained hardware (e.g., sensors) where the full 906 IPsec Architecture is not justified. 908 Because most common platforms now support IPv6 and have it enabled by 909 default, IPv6 security is an issue for networks that are ostensibly 910 IPv4-only; see [RFC7123] for guidance on this area. 912 13.1. Requirements 914 "Security Architecture for the Internet Protocol" [RFC4301] SHOULD be 915 supported by all IPv6 nodes. Note that the IPsec Architecture 916 requires (e.g., Section 4.5 of [RFC4301]) the implementation of both 917 manual and automatic key management. Currently, the default 918 automated key management protocol to implement is IKEv2. As required 919 in [RFC4301], IPv6 nodes implementing the IPsec Architecture MUST 920 implement ESP [RFC4303] and MAY implement AH [RFC4302]. 922 13.2. Transforms and Algorithms 924 The current set of mandatory-to-implement algorithms for the IPsec 925 Architecture are defined in "Cryptographic Algorithm Implementation 926 Requirements For ESP and AH" [RFC7321]. IPv6 nodes implementing the 927 IPsec Architecture MUST conform to the requirements in [RFC7321]. 928 Preferred cryptographic algorithms often change more frequently than 929 security protocols. Therefore, implementations MUST allow for 930 migration to new algorithms, as RFC 7321 is replaced or updated in 931 the future. 933 **BIS update to 7321bis** 935 The current set of mandatory-to-implement algorithms for IKEv2 are 936 defined in "Cryptographic Algorithms for Use in the Internet Key 937 Exchange Version 2 (IKEv2)" [RFC4307]. IPv6 nodes implementing IKEv2 938 MUST conform to the requirements in [RFC4307] and/or any future 939 updates or replacements to [RFC4307]. 941 **BIS update to 4307bis** 943 14. Router-Specific Functionality 945 This section defines general host considerations for IPv6 nodes that 946 act as routers. Currently, this section does not discuss routing- 947 specific requirements; for the case of typical home routers, 948 [RFC7084] defines basic requirements for customer edge routers. 950 **BIS Sync here with work by John Brzozowski et al. in draft-ali- 951 ipv6rtr-reqs-02** 953 14.1. IPv6 Router Alert Option - RFC 2711 955 The IPv6 Router Alert Option [RFC2711] is an optional IPv6 Hop-by-Hop 956 Header that is used in conjunction with some protocols (e.g., RSVP 957 [RFC2205] or Multicast Listener Discovery (MLD) [RFC2710]). The 958 Router Alert option will need to be implemented whenever protocols 959 that mandate its usage (e.g., MLD) are implemented. See 960 Section 5.11. 962 14.2. Neighbor Discovery for IPv6 - RFC 4861 964 Sending Router Advertisements and processing Router Solicitations 965 MUST be supported. 967 Section 7 of [RFC6275] includes some mobility-specific extensions to 968 Neighbor Discovery. Routers SHOULD implement Sections 7.3 and 7.5, 969 even if they do not implement Home Agent functionality. 971 14.3. Stateful Address Autoconfiguration (DHCPv6) - RFC 3315 973 A single DHCP server ([RFC3315] or [RFC4862]) can provide 974 configuration information to devices directly attached to a shared 975 link, as well as to devices located elsewhere within a site. 976 Communication between a client and a DHCP server located on different 977 links requires the use of DHCP relay agents on routers. 979 In simple deployments, consisting of a single router and either a 980 single LAN or multiple LANs attached to the single router, together 981 with a WAN connection, a DHCP server embedded within the router is 982 one common deployment scenario (e.g., [RFC7084]). However, there is 983 no need for relay agents in such scenarios. 985 In more complex deployment scenarios, such as within enterprise or 986 service provider networks, the use of DHCP requires some level of 987 configuration, in order to configure relay agents, DHCP servers, etc. 988 In such environments, the DHCP server might even be run on a 989 traditional server, rather than as part of a router. 991 Because of the wide range of deployment scenarios, support for DHCP 992 server functionality on routers is optional. However, routers 993 targeted for deployment within more complex scenarios (as described 994 above) SHOULD support relay agent functionality. Note that "Basic 995 Requirements for IPv6 Customer Edge Routers" [RFC7084] requires 996 implementation of a DHCPv6 server function in IPv6 Customer Edge (CE) 997 routers. 999 15. Constrained Devices 1001 The target for this document is general IPv6 nodes. In the case of 1002 constrained nodes, with limited CPU, memory, bandwidth or power, 1003 support for certain IPv6 functionality may need to be considered due 1004 to those limitations. The requirements of this document are 1005 RECOMMENDED for all nodes, including constrained nodes, but 1006 compromises may need to be made in certain cases. Where such 1007 compromises are made, the interoperability of devices should be 1008 strongly considered, paticularly where this may impact other nodes on 1009 the same link, e.g., only supporting MLDv1 will affect other nodes. 1011 The IETF 6LowPAN (IPv6 over Low Power LWPAN) WG defined six RFCs, 1012 including a general overview and problem statement ([RFC4919], the 1013 means by which IPv6 packets are transmitted over IEEE 802.15.4 1014 networks [RFC4944] and ND optimisations for that medium [RFC6775]. 1016 **BIS What else to say here? Talk about resource management in 1017 nodes? Low power operation? 1019 16. Network Management 1021 Network management MAY be supported by IPv6 nodes. However, for IPv6 1022 nodes that are embedded devices, network management may be the only 1023 possible way of controlling these nodes. 1025 A node supporting network management SHOULD support NETCONF [RFC6241] 1026 and SNMP configuration [RFC3411]. 1028 16.1. Management Information Base (MIB) Modules 1030 IPv6 MIB have been updated since the last release of the document, 1031 [RFC8096] obseletes several MIBs, the nodes need to not support any 1032 longer. 1034 The following two MIB modules SHOULD be supported by nodes that 1035 support a Simple Network Management Protocol (SNMP) agent. 1037 16.1.1. IP Forwarding Table MIB 1039 The IP Forwarding Table MIB [RFC4292] SHOULD be supported by nodes 1040 that support an SNMP agent. 1042 16.1.2. Management Information Base for the Internet Protocol (IP) 1044 The IP MIB [RFC4293] SHOULD be supported by nodes that support an 1045 SNMP agent. 1047 16.2. YANG Data Models 1049 The following YANG data models SHOULD be supported by nodes that 1050 support a NETCONF agent. 1052 16.2.1. IP Management YANG Model 1054 The IP Management YANG Model [RFC7277] SHOULD be supported by nodes 1055 that support NETCONF. 1057 16.2.2. System Management YANG Model 1059 The System Management YANG Model [RFC7317] SHOULD be supported by 1060 nodes that support NETCONF. 1062 16.2.3. System Management YANG Model 1064 The Interface Management YANG Model [RFC7223] SHOULD be supported by 1065 nodes that support NETCONF. 1067 17. Security Considerations 1069 This document does not directly affect the security of the Internet, 1070 beyond the security considerations associated with the individual 1071 protocols. 1073 Security is also discussed in Section 13 above. 1075 18. IANA Considerations 1077 This document does not require any IANA actions. 1079 19. Authors and Acknowledgments 1080 19.1. Authors and Acknowledgments (Current Document) 1082 For this version of the IPv6 Node Requirements document, the authors 1083 would like to thank Brian Carpenter and Dave Thaler for their 1084 contributions. 1086 19.2. Authors and Acknowledgments from RFC 6434 1088 Ed Jankiewicz and Thomas Narten were named authors of the previous 1089 iteration of this document, RFC6434. 1091 For this version of the document, the authors thanked Hitoshi Asaeda, 1092 Brian Carpenter, Tim Chown, Ralph Droms, Sheila Frankel, Sam Hartman, 1093 Bob Hinden, Paul Hoffman, Pekka Savola, Yaron Sheffer, and Dave 1094 Thaler. 1096 19.3. Authors and Acknowledgments from RFC 4294 1098 The original version of this document (RFC 4294) was written by the 1099 IPv6 Node Requirements design team: 1101 Jari Arkko 1102 jari.arkko@ericsson.com 1104 Marc Blanchet 1105 marc.blanchet@viagenie.qc.ca 1107 Samita Chakrabarti 1108 samita.chakrabarti@eng.sun.com 1110 Alain Durand 1111 alain.durand@sun.com 1113 Gerard Gastaud 1114 gerard.gastaud@alcatel.fr 1116 Jun-ichiro Itojun Hagino 1117 itojun@iijlab.net 1119 Atsushi Inoue 1120 inoue@isl.rdc.toshiba.co.jp 1122 Masahiro Ishiyama 1123 masahiro@isl.rdc.toshiba.co.jp 1125 John Loughney 1126 john.loughney@nokia.com 1128 Rajiv Raghunarayan 1129 raraghun@cisco.com 1130 Shoichi Sakane 1131 shouichi.sakane@jp.yokogawa.com 1133 Dave Thaler 1134 dthaler@windows.microsoft.com 1136 Juha Wiljakka 1137 juha.wiljakka@Nokia.com 1139 The authors would like to thank Ran Atkinson, Jim Bound, Brian 1140 Carpenter, Ralph Droms, Christian Huitema, Adam Machalek, Thomas 1141 Narten, Juha Ollila, and Pekka Savola for their comments. Thanks to 1142 Mark Andrews for comments and corrections on DNS text. Thanks to 1143 Alfred Hoenes for tracking the updates to various RFCs. 1145 20. Appendix: Changes from RFC 6434 1147 There have been many editorial clarifications as well as significant 1148 additions and updates. While this section highlights some of the 1149 changes, readers should not rely on this section for a comprehensive 1150 list of all changes. 1152 1. Restructured sections 1154 2. Added 6LoWPAN to link layers. 1156 3. Removed DOD IPv6 Profile updates. 1158 4. Updated to state MLDv2 support is a MUST. 1160 5. Require DNS RA Options, RFC8106 is a MUST. 1162 6. Added section on constrained devices. 1164 7. Added text on RFC7934, address availability to hosts. 1166 8. Added text on RFC7844, anonymity profiles for DHCPv6 clients. 1168 9. mDNS and DNS-SD added. 1170 10. Added RFC8028 as a SHOULD. 1172 11. Added ECN RFC3168 as a SHOULD. 1174 12. Added reference to RFC7123. 1176 21. Appendix: Changes from RFC 4294 1178 There have been many editorial clarifications as well as significant 1179 additions and updates. While this section highlights some of the 1180 changes, readers should not rely on this section for a comprehensive 1181 list of all changes. 1183 1. Updated the Introduction to indicate that this document is an 1184 applicability statement and is aimed at general nodes. 1186 2. Significantly updated the section on Mobility protocols, adding 1187 references and downgrading previous SHOULDs to MAYs. 1189 3. Changed Sub-IP Layer section to just list relevant RFCs, and 1190 added some more RFCs. 1192 4. Added section on SEND (it is a MAY). 1194 5. Revised section on Privacy Extensions [RFC4941] to add more 1195 nuance to recommendation. 1197 6. Completely revised IPsec/IKEv2 section, downgrading overall 1198 recommendation to a SHOULD. 1200 7. Upgraded recommendation of DHCPv6 to SHOULD. 1202 8. Added background section on DHCP versus RA options, added SHOULD 1203 recommendation for DNS configuration via RAs (RFC6106), and 1204 cleaned up DHCP recommendations. 1206 9. Added recommendation that routers implement Sections 7.3 and 7.5 1207 of [RFC6275]. 1209 10. Added pointer to subnet clarification document [RFC5942]. 1211 11. Added text that "IPv6 Host-to-Router Load Sharing" [RFC4311] 1212 SHOULD be implemented. 1214 12. Added reference to [RFC5722] (Overlapping Fragments), and made 1215 it a MUST to implement. 1217 13. Made "A Recommendation for IPv6 Address Text Representation" 1218 [RFC5952] a SHOULD. 1220 14. Removed mention of "DNAME" from the discussion about [RFC3363]. 1222 15. Numerous updates to reflect newer versions of IPv6 documents, 1223 including [RFC4443], [RFC4291], [RFC3596], and [RFC4213]. 1225 16. Removed discussion of "Managed" and "Other" flags in RAs. There 1226 is no consensus at present on how to process these flags, and 1227 discussion of their semantics was removed in the most recent 1228 update of Stateless Address Autoconfiguration [RFC4862]. 1230 17. Added many more references to optional IPv6 documents. 1232 18. Made "A Recommendation for IPv6 Address Text Representation" 1233 [RFC5952] a SHOULD. 1235 19. Added reference to [RFC5722] (Overlapping Fragments), and made 1236 it a MUST to implement. 1238 20. Updated MLD section to include reference to Lightweight MLD 1239 [RFC5790]. 1241 21. Added SHOULD recommendation for "Default Router Preferences and 1242 More-Specific Routes" [RFC4191]. 1244 22. Made "IPv6 Flow Label Specification" [RFC6437] a SHOULD. 1246 22. References 1248 22.1. Normative References 1250 [RFC1034] Mockapetris, P., "Domain names - concepts and facilities", 1251 STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987, 1252 . 1254 [RFC1035] Mockapetris, P., "Domain names - implementation and 1255 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, 1256 November 1987, . 1258 [RFC1981] McCann, J., Deering, S., and J. Mogul, "Path MTU Discovery 1259 for IP version 6", RFC 1981, DOI 10.17487/RFC1981, August 1260 1996, . 1262 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1263 Requirement Levels", BCP 14, RFC 2119, 1264 DOI 10.17487/RFC2119, March 1997, 1265 . 1267 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 1268 (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460, 1269 December 1998, . 1271 [RFC2710] Deering, S., Fenner, W., and B. Haberman, "Multicast 1272 Listener Discovery (MLD) for IPv6", RFC 2710, 1273 DOI 10.17487/RFC2710, October 1999, 1274 . 1276 [RFC2711] Partridge, C. and A. Jackson, "IPv6 Router Alert Option", 1277 RFC 2711, DOI 10.17487/RFC2711, October 1999, 1278 . 1280 [RFC3168] Ramakrishnan, K., Floyd, S., and D. Black, "The Addition 1281 of Explicit Congestion Notification (ECN) to IP", 1282 RFC 3168, DOI 10.17487/RFC3168, September 2001, 1283 . 1285 [RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, 1286 C., and M. Carney, "Dynamic Host Configuration Protocol 1287 for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July 1288 2003, . 1290 [RFC3411] Harrington, D., Presuhn, R., and B. Wijnen, "An 1291 Architecture for Describing Simple Network Management 1292 Protocol (SNMP) Management Frameworks", STD 62, RFC 3411, 1293 DOI 10.17487/RFC3411, December 2002, 1294 . 1296 [RFC3596] Thomson, S., Huitema, C., Ksinant, V., and M. Souissi, 1297 "DNS Extensions to Support IP Version 6", RFC 3596, 1298 DOI 10.17487/RFC3596, October 2003, 1299 . 1301 [RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol 1302 (DHCP) Service for IPv6", RFC 3736, DOI 10.17487/RFC3736, 1303 April 2004, . 1305 [RFC3810] Vida, R., Ed. and L. Costa, Ed., "Multicast Listener 1306 Discovery Version 2 (MLDv2) for IPv6", RFC 3810, 1307 DOI 10.17487/RFC3810, June 2004, 1308 . 1310 [RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S. 1311 Rose, "DNS Security Introduction and Requirements", 1312 RFC 4033, DOI 10.17487/RFC4033, March 2005, 1313 . 1315 [RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S. 1316 Rose, "Resource Records for the DNS Security Extensions", 1317 RFC 4034, DOI 10.17487/RFC4034, March 2005, 1318 . 1320 [RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S. 1321 Rose, "Protocol Modifications for the DNS Security 1322 Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005, 1323 . 1325 [RFC4213] Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms 1326 for IPv6 Hosts and Routers", RFC 4213, 1327 DOI 10.17487/RFC4213, October 2005, 1328 . 1330 [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing 1331 Architecture", RFC 4291, DOI 10.17487/RFC4291, February 1332 2006, . 1334 [RFC4292] Haberman, B., "IP Forwarding Table MIB", RFC 4292, 1335 DOI 10.17487/RFC4292, April 2006, 1336 . 1338 [RFC4293] Routhier, S., Ed., "Management Information Base for the 1339 Internet Protocol (IP)", RFC 4293, DOI 10.17487/RFC4293, 1340 April 2006, . 1342 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 1343 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, 1344 December 2005, . 1346 [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", 1347 RFC 4303, DOI 10.17487/RFC4303, December 2005, 1348 . 1350 [RFC4307] Schiller, J., "Cryptographic Algorithms for Use in the 1351 Internet Key Exchange Version 2 (IKEv2)", RFC 4307, 1352 DOI 10.17487/RFC4307, December 2005, 1353 . 1355 [RFC4311] Hinden, R. and D. Thaler, "IPv6 Host-to-Router Load 1356 Sharing", RFC 4311, DOI 10.17487/RFC4311, November 2005, 1357 . 1359 [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet 1360 Control Message Protocol (ICMPv6) for the Internet 1361 Protocol Version 6 (IPv6) Specification", RFC 4443, 1362 DOI 10.17487/RFC4443, March 2006, 1363 . 1365 [RFC4607] Holbrook, H. and B. Cain, "Source-Specific Multicast for 1366 IP", RFC 4607, DOI 10.17487/RFC4607, August 2006, 1367 . 1369 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 1370 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 1371 DOI 10.17487/RFC4861, September 2007, 1372 . 1374 [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless 1375 Address Autoconfiguration", RFC 4862, 1376 DOI 10.17487/RFC4862, September 2007, 1377 . 1379 [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy 1380 Extensions for Stateless Address Autoconfiguration in 1381 IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007, 1382 . 1384 [RFC5095] Abley, J., Savola, P., and G. Neville-Neil, "Deprecation 1385 of Type 0 Routing Headers in IPv6", RFC 5095, 1386 DOI 10.17487/RFC5095, December 2007, 1387 . 1389 [RFC5453] Krishnan, S., "Reserved IPv6 Interface Identifiers", 1390 RFC 5453, DOI 10.17487/RFC5453, February 2009, 1391 . 1393 [RFC5722] Krishnan, S., "Handling of Overlapping IPv6 Fragments", 1394 RFC 5722, DOI 10.17487/RFC5722, December 2009, 1395 . 1397 [RFC5790] Liu, H., Cao, W., and H. Asaeda, "Lightweight Internet 1398 Group Management Protocol Version 3 (IGMPv3) and Multicast 1399 Listener Discovery Version 2 (MLDv2) Protocols", RFC 5790, 1400 DOI 10.17487/RFC5790, February 2010, 1401 . 1403 [RFC5942] Singh, H., Beebee, W., and E. Nordmark, "IPv6 Subnet 1404 Model: The Relationship between Links and Subnet 1405 Prefixes", RFC 5942, DOI 10.17487/RFC5942, July 2010, 1406 . 1408 [RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6 1409 Address Text Representation", RFC 5952, 1410 DOI 10.17487/RFC5952, August 2010, 1411 . 1413 [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., 1414 and A. Bierman, Ed., "Network Configuration Protocol 1415 (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, 1416 . 1418 [RFC6437] Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme, 1419 "IPv6 Flow Label Specification", RFC 6437, 1420 DOI 10.17487/RFC6437, November 2011, 1421 . 1423 [RFC6564] Krishnan, S., Woodyatt, J., Kline, E., Hoagland, J., and 1424 M. Bhatia, "A Uniform Format for IPv6 Extension Headers", 1425 RFC 6564, DOI 10.17487/RFC6564, April 2012, 1426 . 1428 [RFC6724] Thaler, D., Ed., Draves, R., Matsumoto, A., and T. Chown, 1429 "Default Address Selection for Internet Protocol Version 6 1430 (IPv6)", RFC 6724, DOI 10.17487/RFC6724, September 2012, 1431 . 1433 [RFC6762] Cheshire, S. and M. Krochmal, "Multicast DNS", RFC 6762, 1434 DOI 10.17487/RFC6762, February 2013, 1435 . 1437 [RFC6763] Cheshire, S. and M. Krochmal, "DNS-Based Service 1438 Discovery", RFC 6763, DOI 10.17487/RFC6763, February 2013, 1439 . 1441 [RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C. 1442 Bormann, "Neighbor Discovery Optimization for IPv6 over 1443 Low-Power Wireless Personal Area Networks (6LoWPANs)", 1444 RFC 6775, DOI 10.17487/RFC6775, November 2012, 1445 . 1447 [RFC6891] Damas, J., Graff, M., and P. Vixie, "Extension Mechanisms 1448 for DNS (EDNS(0))", STD 75, RFC 6891, 1449 DOI 10.17487/RFC6891, April 2013, 1450 . 1452 [RFC6946] Gont, F., "Processing of IPv6 "Atomic" Fragments", 1453 RFC 6946, DOI 10.17487/RFC6946, May 2013, 1454 . 1456 [RFC7045] Carpenter, B. and S. Jiang, "Transmission and Processing 1457 of IPv6 Extension Headers", RFC 7045, 1458 DOI 10.17487/RFC7045, December 2013, 1459 . 1461 [RFC7048] Nordmark, E. and I. Gashinsky, "Neighbor Unreachability 1462 Detection Is Too Impatient", RFC 7048, 1463 DOI 10.17487/RFC7048, January 2014, 1464 . 1466 [RFC7112] Gont, F., Manral, V., and R. Bonica, "Implications of 1467 Oversized IPv6 Header Chains", RFC 7112, 1468 DOI 10.17487/RFC7112, January 2014, 1469 . 1471 [RFC7217] Gont, F., "A Method for Generating Semantically Opaque 1472 Interface Identifiers with IPv6 Stateless Address 1473 Autoconfiguration (SLAAC)", RFC 7217, 1474 DOI 10.17487/RFC7217, April 2014, 1475 . 1477 [RFC7223] Bjorklund, M., "A YANG Data Model for Interface 1478 Management", RFC 7223, DOI 10.17487/RFC7223, May 2014, 1479 . 1481 [RFC7277] Bjorklund, M., "A YANG Data Model for IP Management", 1482 RFC 7277, DOI 10.17487/RFC7277, June 2014, 1483 . 1485 [RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T. 1486 Kivinen, "Internet Key Exchange Protocol Version 2 1487 (IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October 1488 2014, . 1490 [RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for 1491 System Management", RFC 7317, DOI 10.17487/RFC7317, August 1492 2014, . 1494 [RFC7321] McGrew, D. and P. Hoffman, "Cryptographic Algorithm 1495 Implementation Requirements and Usage Guidance for 1496 Encapsulating Security Payload (ESP) and Authentication 1497 Header (AH)", RFC 7321, DOI 10.17487/RFC7321, August 2014, 1498 . 1500 [RFC7527] Asati, R., Singh, H., Beebee, W., Pignataro, C., Dart, E., 1501 and W. George, "Enhanced Duplicate Address Detection", 1502 RFC 7527, DOI 10.17487/RFC7527, April 2015, 1503 . 1505 [RFC7559] Krishnan, S., Anipko, D., and D. Thaler, "Packet-Loss 1506 Resiliency for Router Solicitations", RFC 7559, 1507 DOI 10.17487/RFC7559, May 2015, 1508 . 1510 [RFC7739] Gont, F., "Security Implications of Predictable Fragment 1511 Identification Values", RFC 7739, DOI 10.17487/RFC7739, 1512 February 2016, . 1514 [RFC8021] Gont, F., Liu, W., and T. Anderson, "Generation of IPv6 1515 Atomic Fragments Considered Harmful", RFC 8021, 1516 DOI 10.17487/RFC8021, January 2017, 1517 . 1519 [RFC8106] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli, 1520 "IPv6 Router Advertisement Options for DNS Configuration", 1521 RFC 8106, DOI 10.17487/RFC8106, March 2017, 1522 . 1524 22.2. Informative References 1526 [RFC0793] Postel, J., "Transmission Control Protocol", STD 7, 1527 RFC 793, DOI 10.17487/RFC0793, September 1981, 1528 . 1530 [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S. 1531 Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 1532 Functional Specification", RFC 2205, DOI 10.17487/RFC2205, 1533 September 1997, . 1535 [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet 1536 Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, 1537 . 1539 [RFC2491] Armitage, G., Schulter, P., Jork, M., and G. Harter, "IPv6 1540 over Non-Broadcast Multiple Access (NBMA) networks", 1541 RFC 2491, DOI 10.17487/RFC2491, January 1999, 1542 . 1544 [RFC2492] Armitage, G., Schulter, P., and M. Jork, "IPv6 over ATM 1545 Networks", RFC 2492, DOI 10.17487/RFC2492, January 1999, 1546 . 1548 [RFC2590] Conta, A., Malis, A., and M. Mueller, "Transmission of 1549 IPv6 Packets over Frame Relay Networks Specification", 1550 RFC 2590, DOI 10.17487/RFC2590, May 1999, 1551 . 1553 [RFC2675] Borman, D., Deering, S., and R. Hinden, "IPv6 Jumbograms", 1554 RFC 2675, DOI 10.17487/RFC2675, August 1999, 1555 . 1557 [RFC3146] Fujisawa, K. and A. Onoe, "Transmission of IPv6 Packets 1558 over IEEE 1394 Networks", RFC 3146, DOI 10.17487/RFC3146, 1559 October 2001, . 1561 [RFC3363] Bush, R., Durand, A., Fink, B., Gudmundsson, O., and T. 1562 Hain, "Representing Internet Protocol version 6 (IPv6) 1563 Addresses in the Domain Name System (DNS)", RFC 3363, 1564 DOI 10.17487/RFC3363, August 2002, 1565 . 1567 [RFC3493] Gilligan, R., Thomson, S., Bound, J., McCann, J., and W. 1568 Stevens, "Basic Socket Interface Extensions for IPv6", 1569 RFC 3493, DOI 10.17487/RFC3493, February 2003, 1570 . 1572 [RFC3542] Stevens, W., Thomas, M., Nordmark, E., and T. Jinmei, 1573 "Advanced Sockets Application Program Interface (API) for 1574 IPv6", RFC 3542, DOI 10.17487/RFC3542, May 2003, 1575 . 1577 [RFC3678] Thaler, D., Fenner, B., and B. Quinn, "Socket Interface 1578 Extensions for Multicast Source Filters", RFC 3678, 1579 DOI 10.17487/RFC3678, January 2004, 1580 . 1582 [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility 1583 Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 1584 2011, . 1586 [RFC3776] Arkko, J., Devarapalli, V., and F. Dupont, "Using IPsec to 1587 Protect Mobile IPv6 Signaling Between Mobile Nodes and 1588 Home Agents", RFC 3776, DOI 10.17487/RFC3776, June 2004, 1589 . 1591 [RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, 1592 "SEcure Neighbor Discovery (SEND)", RFC 3971, 1593 DOI 10.17487/RFC3971, March 2005, 1594 . 1596 [RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)", 1597 RFC 3972, DOI 10.17487/RFC3972, March 2005, 1598 . 1600 [RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and 1601 More-Specific Routes", RFC 4191, DOI 10.17487/RFC4191, 1602 November 2005, . 1604 [RFC4302] Kent, S., "IP Authentication Header", RFC 4302, 1605 DOI 10.17487/RFC4302, December 2005, 1606 . 1608 [RFC4338] DeSanti, C., Carlson, C., and R. Nixon, "Transmission of 1609 IPv6, IPv4, and Address Resolution Protocol (ARP) Packets 1610 over Fibre Channel", RFC 4338, DOI 10.17487/RFC4338, 1611 January 2006, . 1613 [RFC4380] Huitema, C., "Teredo: Tunneling IPv6 over UDP through 1614 Network Address Translations (NATs)", RFC 4380, 1615 DOI 10.17487/RFC4380, February 2006, 1616 . 1618 [RFC4429] Moore, N., "Optimistic Duplicate Address Detection (DAD) 1619 for IPv6", RFC 4429, DOI 10.17487/RFC4429, April 2006, 1620 . 1622 [RFC4584] Chakrabarti, S. and E. Nordmark, "Extension to Sockets API 1623 for Mobile IPv6", RFC 4584, DOI 10.17487/RFC4584, July 1624 2006, . 1626 [RFC4821] Mathis, M. and J. Heffner, "Packetization Layer Path MTU 1627 Discovery", RFC 4821, DOI 10.17487/RFC4821, March 2007, 1628 . 1630 [RFC4877] Devarapalli, V. and F. Dupont, "Mobile IPv6 Operation with 1631 IKEv2 and the Revised IPsec Architecture", RFC 4877, 1632 DOI 10.17487/RFC4877, April 2007, 1633 . 1635 [RFC4884] Bonica, R., Gan, D., Tappan, D., and C. Pignataro, 1636 "Extended ICMP to Support Multi-Part Messages", RFC 4884, 1637 DOI 10.17487/RFC4884, April 2007, 1638 . 1640 [RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6 1641 over Low-Power Wireless Personal Area Networks (6LoWPANs): 1642 Overview, Assumptions, Problem Statement, and Goals", 1643 RFC 4919, DOI 10.17487/RFC4919, August 2007, 1644 . 1646 [RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler, 1647 "Transmission of IPv6 Packets over IEEE 802.15.4 1648 Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007, 1649 . 1651 [RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6 1652 Socket API for Source Address Selection", RFC 5014, 1653 DOI 10.17487/RFC5014, September 2007, 1654 . 1656 [RFC5072] Varada, S., Ed., Haskins, D., and E. Allen, "IP Version 6 1657 over PPP", RFC 5072, DOI 10.17487/RFC5072, September 2007, 1658 . 1660 [RFC5121] Patil, B., Xia, F., Sarikaya, B., Choi, JH., and S. 1661 Madanapalli, "Transmission of IPv6 via the IPv6 1662 Convergence Sublayer over IEEE 802.16 Networks", RFC 5121, 1663 DOI 10.17487/RFC5121, February 2008, 1664 . 1666 [RFC5555] Soliman, H., Ed., "Mobile IPv6 Support for Dual Stack 1667 Hosts and Routers", RFC 5555, DOI 10.17487/RFC5555, June 1668 2009, . 1670 [RFC6563] Jiang, S., Conrad, D., and B. Carpenter, "Moving A6 to 1671 Historic Status", RFC 6563, DOI 10.17487/RFC6563, March 1672 2012, . 1674 [RFC7066] Korhonen, J., Ed., Arkko, J., Ed., Savolainen, T., and S. 1675 Krishnan, "IPv6 for Third Generation Partnership Project 1676 (3GPP) Cellular Hosts", RFC 7066, DOI 10.17487/RFC7066, 1677 November 2013, . 1679 [RFC7084] Singh, H., Beebee, W., Donley, C., and B. Stark, "Basic 1680 Requirements for IPv6 Customer Edge Routers", RFC 7084, 1681 DOI 10.17487/RFC7084, November 2013, 1682 . 1684 [RFC7123] Gont, F. and W. Liu, "Security Implications of IPv6 on 1685 IPv4 Networks", RFC 7123, DOI 10.17487/RFC7123, February 1686 2014, . 1688 [RFC7278] Byrne, C., Drown, D., and A. Vizdal, "Extending an IPv6 1689 /64 Prefix from a Third Generation Partnership Project 1690 (3GPP) Mobile Interface to a LAN Link", RFC 7278, 1691 DOI 10.17487/RFC7278, June 2014, 1692 . 1694 [RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy 1695 Considerations for IPv6 Address Generation Mechanisms", 1696 RFC 7721, DOI 10.17487/RFC7721, March 2016, 1697 . 1699 [RFC7844] Huitema, C., Mrugalski, T., and S. Krishnan, "Anonymity 1700 Profiles for DHCP Clients", RFC 7844, 1701 DOI 10.17487/RFC7844, May 2016, 1702 . 1704 [RFC7934] Colitti, L., Cerf, V., Cheshire, S., and D. Schinazi, 1705 "Host Address Availability Recommendations", BCP 204, 1706 RFC 7934, DOI 10.17487/RFC7934, July 2016, 1707 . 1709 [RFC8028] Baker, F. and B. Carpenter, "First-Hop Router Selection by 1710 Hosts in a Multi-Prefix Network", RFC 8028, 1711 DOI 10.17487/RFC8028, November 2016, 1712 . 1714 [RFC8096] Fenner, B., "The IPv6-Specific MIB Modules Are Obsolete", 1715 RFC 8096, DOI 10.17487/RFC8096, April 2017, 1716 . 1718 [POSIX] IEEE, "IEEE Std. 1003.1-2008 Standard for Information 1719 Technology -- Portable Operating System Interface (POSIX), 1720 ISO/IEC 9945:2009", . 1722 [USGv6] National Institute of Standards and Technology, "A Profile 1723 for IPv6 in the U.S. Government - Version 1.0", July 2008, 1724 . 1726 Authors' Addresses 1728 Tim Chown 1729 Jisc 1730 Lumen House, Library Avenue 1731 Harwell Oxford, Didcot OX11 0SG 1732 United Kingdom 1734 Email: tim.chown@jisc.ac.uk 1736 John Loughney 1737 Nokia 1738 200 South Mathilda Ave. 1739 Sunnyvale, CA 94086 1740 USA 1742 Phone: +1 650 283 8068 1743 Email: john.loughney@nokia.com 1745 Timothy Winters 1746 University of New Hampshire 1747 InterOperability Laboratory 1748 Durham NH 1749 United States 1751 Email: twinters@iol.unh.edu