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Checking references for intended status: Informational ---------------------------------------------------------------------------- ** Obsolete normative reference: RFC 3315 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 3633 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 3736 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 4242 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 6106 (Obsoleted by RFC 8106) ** Obsolete normative reference: RFC 6434 (Obsoleted by RFC 8504) ** Obsolete normative reference: RFC 7083 (Obsoleted by RFC 8415) -- Obsolete informational reference (is this intentional?): RFC 7550 (Obsoleted by RFC 8415) Summary: 8 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 IPv6 Operations (v6ops) J. Palet Martinez 3 Internet-Draft Consulintel, S.L. 4 Obsoletes: 7084 (if approved) June 9, 2017 5 Intended status: Informational 6 Expires: December 11, 2017 8 Basic Requirements for IPv6 Customer Edge Routers 9 draft-ietf-v6ops-rfc7084-bis-03 11 Abstract 13 This document specifies requirements for an IPv6 Customer Edge (CE) 14 router. Specifically, the current version of this document focuses 15 on the basic provisioning of an IPv6 CE router and the provisioning 16 of IPv6 hosts attached to it. The document also covers several 17 transition technologies, as required in a world where IPv4 addresses 18 are no longer available, so hosts in the customer LANs with IPv4-only 19 or IPv6-only applications or devices, requiring to communicate with 20 IPv4-only services at the Internet, are able to do so. The document 21 obsoletes RFC 7084. 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 11, 2017. 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. Requirements Language . . . . . . . . . . . . . . . . . . 3 59 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 60 3. Usage Scenarios . . . . . . . . . . . . . . . . . . . . . . . 5 61 4. Architecture . . . . . . . . . . . . . . . . . . . . . . . . 6 62 4.1. Current IPv4 End-User Network Architecture . . . . . . . 6 63 4.2. IPv6 End-User Network Architecture . . . . . . . . . . . 7 64 4.2.1. Local Communication . . . . . . . . . . . . . . . . . 8 65 5. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 9 66 5.1. General Requirements . . . . . . . . . . . . . . . . . . 9 67 5.2. WAN-Side Configuration . . . . . . . . . . . . . . . . . 9 68 5.3. LAN-Side Configuration . . . . . . . . . . . . . . . . . 13 69 5.4. Transition Technologies Support . . . . . . . . . . . . . 15 70 5.4.1. IPv4 Service Continuity in Customer LANs . . . . . . 16 71 5.4.1.1. 464XLAT . . . . . . . . . . . . . . . . . . . . . 16 72 5.4.1.2. Dual-Stack Lite (DS-Lite) . . . . . . . . . . . . 16 73 5.4.1.3. Lightweight 4over6 (lw4o6) . . . . . . . . . . . 17 74 5.4.1.4. MAP-E . . . . . . . . . . . . . . . . . . . . . . 17 75 5.4.1.5. MAP-T . . . . . . . . . . . . . . . . . . . . . . 18 76 5.4.2. Support of IPv6 in IPv4-only WAN access . . . . . . . 18 77 5.4.2.1. 6in4 . . . . . . . . . . . . . . . . . . . . . . 18 78 5.4.2.2. 6rd . . . . . . . . . . . . . . . . . . . . . . . 20 79 5.5. IPv4 Multicast Support . . . . . . . . . . . . . . . . . 21 80 5.6. Security Considerations . . . . . . . . . . . . . . . . . 21 81 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22 82 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22 83 8. ANNEX A: Code Considerations . . . . . . . . . . . . . . . . 23 84 9. ANNEX B: Changes from RFC7084 . . . . . . . . . . . . . . . . 23 85 10. ANNEX C: Changes from RFC7084-bis-00 . . . . . . . . . . . . 24 86 11. ANNEX D: Changes from RFC7084-bis-01 . . . . . . . . . . . . 24 87 12. ANNEX E: Changes from RFC7084-bis-02 . . . . . . . . . . . . 25 88 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 25 89 13.1. Normative References . . . . . . . . . . . . . . . . . . 25 90 13.2. Informative References . . . . . . . . . . . . . . . . . 30 91 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 30 93 1. Introduction 95 This document defines basic IPv6 features for a residential or small- 96 office router, referred to as an "IPv6 CE router", in order to 97 establish an industry baseline for features to be implemented on such 98 a router. 100 These routers typically also support IPv4, at least in the LAN side. 102 This document specifies how an IPv6 CE router automatically 103 provisions its WAN interface, acquires address space for provisioning 104 of its LAN interfaces, and fetches other configuration information 105 from the service provider network. Automatic provisioning of more 106 complex topology than a single router with multiple LAN interfaces is 107 out of scope for this document. In some cases, manual provisioning 108 may be acceptable, when intended for a small number of customers. 110 This document doesn't cover the specific details of each possible 111 access technology. For example, if the CE is supporting built-in or 112 external 3GPP/LTE interfaces, [RFC7849] is a relevant reference. See 113 [RFC4779] for a discussion of options available for deploying IPv6 in 114 wireline service provider access networks. 116 This document also covers the IP transition technologies required in 117 a world where IPv4 addresses are no longer available, so the service 118 providers need to provision IPv6-only WAN access, while at the same 119 time ensuring that IPv4-only or IPv6-only devices or applications in 120 the customer LANs can still reach IPv4-only devices or applications 121 in Internet, which still don't have IPv6 support. 123 1.1. Requirements Language 125 Take careful note: Unlike other IETF documents, the key words "MUST", 126 "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", 127 "RECOMMENDED", "MAY", and "OPTIONAL" in this document are not used as 128 described in RFC 2119 [RFC2119]. This document uses these keywords 129 not strictly for the purpose of interoperability, but rather for the 130 purpose of establishing industry-common baseline functionality. As 131 such, the document points to several other specifications (preferable 132 in RFC or stable form) to provide additional guidance to implementers 133 regarding any protocol implementation required to produce a 134 successful CE router that interoperates successfully with a 135 particular subset of currently deploying and planned common IPv6 136 access networks. 138 2. Terminology 140 End-User Network one or more links attached to the IPv6 CE 141 router that connect IPv6 hosts. 143 IPv6 Customer Edge Router a node intended for home or small-office 144 use that forwards IPv6 packets not 145 explicitly addressed to itself. The IPv6 146 CE router connects the end-user network to 147 a service provider network. In other 148 documents, the CE is named as CPE (Customer 149 Premises Equipment or Customer Provided 150 Equipment). In the context of this 151 document, both terminologies are 152 synonymous. 154 IPv6 Host any device implementing an IPv6 stack 155 receiving IPv6 connectivity through the 156 IPv6 CE router. 158 LAN Interface an IPv6 CE router's attachment to a link in 159 the end-user network. Examples are 160 Ethernet (simple or bridged), 802.11 161 wireless, or other LAN technologies. An 162 IPv6 CE router may have one or more 163 network-layer LAN interfaces. 165 Service Provider an entity that provides access to the 166 Internet. In this document, a service 167 provider specifically offers Internet 168 access using IPv6, and it may also offer 169 IPv4 Internet access. The service provider 170 can provide such access over a variety of 171 different transport methods such as FTTH, 172 DSL, cable, wireless, 3GPP/LTE, and others. 174 WAN Interface an IPv6 CE router's attachment to a link 175 used to provide connectivity to the service 176 provider network; example link technologies 177 include Ethernet (simple or bridged), PPP 178 links, Frame Relay, or ATM networks, as 179 well as Internet-layer (or higher-layer) 180 "tunnels", such as tunnels over IPv4 or 181 IPv6 itself. 183 3. Usage Scenarios 185 The IPv6 CE router described in this document is expected to be used 186 typically, in any of the following scenarios: 188 1. Residential/household users. Common usage is any kind of 189 Internet access (web, email, streaming, online gaming, etc.). 191 2. Residential with Small Office/Home Office (SOHO). Same usage as 192 for the first scenario. 194 3. Small Office/Home Office (SOHO). Same usage as for the first 195 scenario. 197 4. Small and Medium Enterprise (SME). Same usage as for the first 198 scenario. 200 5. Residential/household with advanced requirements. Same basic 201 usage as for the first scenario, however there may be 202 requirements for exporting services to the WAN (IP cameras, web, 203 DNS, email, VPN, etc.). 205 6. Small and Medium Enterprise (SME) with advanced requirements. 206 Same basic usage as for the first scenario, however there may be 207 requirements for exporting services to the WAN (IP cameras, web, 208 DNS, email, VPN, etc.). 210 The above list is not intended to be comprehensive of all the 211 possible usage scenarios, just the main ones. In fact, combinations 212 of the above usages are also possible, for example a residential with 213 SOHO and advanced requirements. 215 The mechanisms for exporting IPv6 services are commonly "naturally" 216 available in any IPv6 router, as when using GUA, unless they are 217 blocked by firewall rules, which may require some manual 218 configuration by means of a GUI and/or CLI. 220 However, in the case of IPv4, because the usage of private addresses 221 and NAT, it typically requires some degree of manual configuration 222 such as setting up a DMZ, virtual servers, or port/protocol 223 forwarding. In general, CE routers already provide GUI and/or CLI to 224 manually configure them, or the possibility to setup the CE in bridge 225 mode, so another CE behind it, takes care of that. It is out of the 226 scope of this document the definition of any requirements for that. 228 The main difference for an IPv6 CE router to support one or several 229 of the above indicated scenarios, is related to the packet processing 230 capabilities, performance, even other details such as the number of 231 WAN/LAN interfaces, their maximum speed, memory for keeping tables or 232 tracking connections, etc. So, it is out of the scope of this 233 document to classify them. 235 For example, an SME may have just 10 employees (micro-SME), which 236 commonly will be considered same as a SOHO, but a small SME can have 237 up to 50 employees, or 250 for a medium one. Depending on the IPv6 238 CE router capabilities or even how it is being configured (for 239 instance, using SLAAC or DHCPv6), it may support even a higher number 240 of employees if the traffic in the LANs is low, or switched by 241 another device(s), or the WAN bandwidth requirements are low, etc. 242 The actual bandwidth capabilities of access with technologies such as 243 FTTH, cable and even 3GPP/LTE, allows the support of such usages, and 244 indeed, is a very common situation that access networks and the CE 245 provided by the service provider are the same for SMEs and 246 residential users. 248 There is also no difference in terms of who actually provides the 249 IPv6 CE router. In most of the cases is the service provider, and in 250 fact is responsible, typically, of provisioning/managing at least the 251 WAN side. However, commonly the user has access to configure the LAN 252 interfaces, firewall, DMZ, and many other aspects. In fact, in many 253 cases, the user must supply, or at least can replace the IPv6 CE 254 router, which makes even more relevant that all the IPv6 CE routers, 255 support the same requirements defined in this document. 257 The IPv6 CE router described in this document is not intended for 258 usage in other scenarios such as bigger Enterprises, Data Centers, 259 Content Providers, etc. So, even if the documented requirements meet 260 their needs, may have additional requirements, which are out of the 261 scope of this document. 263 4. Architecture 265 4.1. Current IPv4 End-User Network Architecture 267 An end-user network will likely support both IPv4 and IPv6. It is 268 not expected that an end user will change their existing network 269 topology with the introduction of IPv6. There are some differences 270 in how IPv6 works and is provisioned; these differences have 271 implications for the network architecture. A typical IPv4 end-user 272 network consists of a "plug and play" router with NAT functionality 273 and a single link behind it, connected to the service provider 274 network. 276 A typical IPv4 NAT deployment by default blocks all incoming 277 connections. Opening of ports is typically allowed using a Universal 278 Plug and Play Internet Gateway Device (UPnP IGD) [UPnP-IGD] or some 279 other firewall control protocol. 281 Another consequence of using private address space in the end-user 282 network is that it provides stable addressing; that is, it never 283 changes even when you change service providers, and the addresses are 284 always there even when the WAN interface is down or the customer edge 285 router has not yet been provisioned. 287 Many existing routers support dynamic routing (which learns routes 288 from other routers), and advanced end-users can build arbitrary, 289 complex networks using manual configuration of address prefixes 290 combined with a dynamic routing protocol. 292 4.2. IPv6 End-User Network Architecture 294 The end-user network architecture for IPv6 should provide equivalent 295 or better capabilities and functionality than the current IPv4 296 architecture. 298 The end-user network is a stub network. Figure 1 illustrates the 299 model topology for the end-user network. 301 +-------+-------+ \ 302 | Service | \ 303 | Provider | | Service 304 | Router | | Provider 305 +-------+-------+ | Network 306 | / 307 | Customer / 308 | Internet Connection / 309 | 310 +------+--------+ \ 311 | IPv6 | \ 312 | Customer Edge | \ 313 | Router | / 314 +---+-------+-+-+ / 315 Network A | | Network B | End-User 316 ---+-------------+----+- --+--+-------------+--- | Network(s) 317 | | | | \ 318 +----+-----+ +-----+----+ +----+-----+ +-----+----+ \ 319 |IPv6 Host | |IPv6 Host | | IPv6 Host| |IPv6 Host | / 320 | | | | | | | | / 321 +----------+ +-----+----+ +----------+ +----------+ / 323 Figure 1: An Example of a Typical End-User Network 325 This architecture describes the: 327 o Basic capabilities of an IPv6 CE router 329 o Provisioning of the WAN interface connecting to the service 330 provider 332 o Provisioning of the LAN interfaces 334 For IPv6 multicast traffic, the IPv6 CE router may act as a Multicast 335 Listener Discovery (MLD) proxy [RFC4605] and may support a dynamic 336 multicast routing protocol. 338 The IPv6 CE router may be manually configured in an arbitrary 339 topology with a dynamic routing protocol. Automatic provisioning and 340 configuration is described for a single IPv6 CE router only. 342 4.2.1. Local Communication 344 Link-local IPv6 addresses are used by hosts communicating on a single 345 link. Unique Local IPv6 Unicast Addresses (ULAs) [RFC4193] are used 346 by hosts communicating within the end-user network across multiple 347 links, but without requiring the application to use a globally 348 routable address. The IPv6 CE router defaults to acting as the 349 demarcation point between two networks by providing a ULA boundary, a 350 multicast zone boundary, and ingress and egress traffic filters. 352 At the time of this writing, several host implementations do not 353 handle the case where they have an IPv6 address configured and no 354 IPv6 connectivity, either because the address itself has a limited 355 topological reachability (e.g., ULA) or because the IPv6 CE router is 356 not connected to the IPv6 network on its WAN interface. To support 357 host implementations that do not handle multihoming in a multi-prefix 358 environment [RFC7157], the IPv6 CE router should not, as detailed in 359 the requirements below, advertise itself as a default router on the 360 LAN interface(s) when it does not have IPv6 connectivity on the WAN 361 interface or when it is not provisioned with IPv6 addresses. For 362 local IPv6 communication, the mechanisms specified in [RFC4191] are 363 used. 365 ULA addressing is useful where the IPv6 CE router has multiple LAN 366 interfaces with hosts that need to communicate with each other. If 367 the IPv6 CE router has only a single LAN interface (IPv6 link), then 368 link-local addressing can be used instead. 370 Coexistence with IPv4 requires any IPv6 CE router(s) on the LAN to 371 conform to these recommendations, especially requirements ULA-5 and 372 L-4 below. 374 5. Requirements 376 5.1. General Requirements 378 The IPv6 CE router is responsible for implementing IPv6 routing; that 379 is, the IPv6 CE router must look up the IPv6 destination address in 380 its routing table to decide to which interface it should send the 381 packet. 383 In this role, the IPv6 CE router is responsible for ensuring that 384 traffic using its ULA addressing does not go out the WAN interface 385 and does not originate from the WAN interface. 387 G-1: An IPv6 CE router is an IPv6 node according to the IPv6 Node 388 Requirements specification [RFC6434]. 390 G-2: The IPv6 CE router MUST implement ICMPv6 according to 391 [RFC4443]. In particular, point-to-point links MUST be handled 392 as described in Section 3.1 of [RFC4443]. 394 G-3: The IPv6 CE router MUST NOT forward any IPv6 traffic between 395 its LAN interface(s) and its WAN interface until the router has 396 successfully completed the IPv6 address and the delegated 397 prefix acquisition process. 399 G-4: By default, an IPv6 CE router that has no default router(s) on 400 its WAN interface MUST NOT advertise itself as an IPv6 default 401 router on its LAN interfaces. That is, the "Router Lifetime" 402 field is set to zero in all Router Advertisement messages it 403 originates [RFC4861]. 405 G-5: By default, if the IPv6 CE router is an advertising router and 406 loses its IPv6 default router(s) and/or detects loss of 407 connectivity on the WAN interface, it MUST explicitly 408 invalidate itself as an IPv6 default router on each of its 409 advertising interfaces by immediately transmitting one or more 410 Router Advertisement messages with the "Router Lifetime" field 411 set to zero [RFC4861]. 413 G-6: The IPv6 CE router MUST comply with [RFC7608]. 415 5.2. WAN-Side Configuration 417 The IPv6 CE router will need to support connectivity to one or more 418 access network architectures. This document describes an IPv6 CE 419 router that is not specific to any particular architecture or service 420 provider and that supports all commonly used architectures. 422 IPv6 Neighbor Discovery and DHCPv6 protocols operate over any type of 423 IPv6-supported link layer, and there is no need for a link-layer- 424 specific configuration protocol for IPv6 network-layer configuration 425 options as in, e.g., PPP IP Control Protocol (IPCP) for IPv4. This 426 section makes the assumption that the same mechanism will work for 427 any link layer, be it Ethernet, the Data Over Cable Service Interface 428 Specification (DOCSIS), PPP, or others. 430 WAN-side requirements: 432 W-1: When the router is attached to the WAN interface link, it MUST 433 act as an IPv6 host for the purposes of stateless [RFC4862] or 434 stateful [RFC3315] interface address assignment. 436 W-2: The IPv6 CE router MUST generate a link-local address and 437 finish Duplicate Address Detection according to [RFC4862] prior 438 to sending any Router Solicitations on the interface. The 439 source address used in the subsequent Router Solicitation MUST 440 be the link-local address on the WAN interface. 442 W-3: Absent other routing information, the IPv6 CE router MUST use 443 Router Discovery as specified in [RFC4861] to discover a 444 default router(s) and install a default route(s) in its routing 445 table with the discovered router's address as the next hop. 447 W-4: The router MUST act as a requesting router for the purposes of 448 DHCPv6 prefix delegation ([RFC3633]). 450 W-5: The IPv6 CE router MUST use a persistent DHCP Unique Identifier 451 (DUID) for DHCPv6 messages. The DUID MUST NOT change between 452 network-interface resets or IPv6 CE router reboots. 454 W-6: The WAN interface of the CE router SHOULD support a Port 455 Control Protocol (PCP) client as specified in [RFC6887] for use 456 by applications on the CE router. The PCP client SHOULD follow 457 the procedure specified in Section 8.1 of [RFC6887] to discover 458 its PCP server. This document takes no position on whether 459 such functionality is enabled by default or mechanisms by which 460 users would configure the functionality. Handling PCP requests 461 from PCP clients in the LAN side of the CE router is out of 462 scope. 464 Link-layer requirements: 466 WLL-1: If the WAN interface supports Ethernet encapsulation, then 467 the IPv6 CE router MUST support IPv6 over Ethernet [RFC2464]. 469 WLL-2: If the WAN interface supports PPP encapsulation, the IPv6 CE 470 router MUST support IPv6 over PPP [RFC5072]. 472 WLL-3: If the WAN interface supports PPP encapsulation, in a dual- 473 stack environment with IPCP and IPV6CP running over one PPP 474 logical channel, the Network Control Protocols (NCPs) MUST be 475 treated as independent of each other and start and terminate 476 independently. 478 Address assignment requirements: 480 WAA-1: The IPv6 CE router MUST support Stateless Address 481 Autoconfiguration (SLAAC) [RFC4862]. 483 WAA-2: The IPv6 CE router MUST follow the recommendations in 484 Section 4 of [RFC5942], and in particular the handling of 485 the L flag in the Router Advertisement Prefix Information 486 option. 488 WAA-3: The IPv6 CE router MUST support DHCPv6 [RFC3315] client 489 behavior. 491 WAA-4: The IPv6 CE router MUST be able to support the following 492 DHCPv6 options: Identity Association for Non-temporary 493 Address (IA_NA), Reconfigure Accept [RFC3315], and 494 DNS_SERVERS [RFC3646]. The IPv6 CE router SHOULD be able to 495 support the DNS Search List (DNSSL) option as specified in 496 [RFC3646]. 498 WAA-5: The IPv6 CE router SHOULD implement the Network Time 499 Protocol (NTP) as specified in [RFC5905] to provide a time 500 reference common to the service provider for other 501 protocols, such as DHCPv6, to use. If the CE router 502 implements NTP, it requests the NTP Server DHCPv6 option 503 [RFC5908] and uses the received list of servers as primary 504 time reference, unless explicitly configured otherwise. LAN 505 side support of NTP is out of scope for this document. 507 WAA-6: If the IPv6 CE router receives a Router Advertisement 508 message (described in [RFC4861]) with the M flag set to 1, 509 the IPv6 CE router MUST do DHCPv6 address assignment 510 (request an IA_NA option). 512 WAA-7: If the IPv6 CE router does not acquire a global IPv6 513 address(es) from either SLAAC or DHCPv6, then it MUST create 514 a global IPv6 address(es) from its delegated prefix(es) and 515 configure those on one of its internal virtual network 516 interfaces, unless configured to require a global IPv6 517 address on the WAN interface. 519 WAA-8: The CE router MUST support the SOL_MAX_RT option [RFC7083] 520 and request the SOL_MAX_RT option in an Option Request 521 Option (ORO). 523 WAA-9: As a router, the IPv6 CE router MUST follow the weak host 524 (Weak End System) model [RFC1122]. When originating packets 525 from an interface, it will use a source address from another 526 one of its interfaces if the outgoing interface does not 527 have an address of suitable scope. 529 WAA-10: The IPv6 CE router SHOULD implement the Information Refresh 530 Time option and associated client behavior as specified in 531 [RFC4242]. 533 Prefix delegation requirements: 535 WPD-1: The IPv6 CE router MUST support DHCPv6 prefix delegation 536 requesting router behavior as specified in [RFC3633] 537 (Identity Association for Prefix Delegation (IA_PD) option). 539 WPD-2: The IPv6 CE router MAY indicate as a hint to the delegating 540 router the size of the prefix it requires. If so, it MUST 541 ask for a prefix large enough to assign one /64 for each of 542 its interfaces, rounded up to the nearest nibble, and SHOULD 543 be configurable to ask for more. 545 WPD-3: The IPv6 CE router MUST be prepared to accept a delegated 546 prefix size different from what is given in the hint. If the 547 delegated prefix is too small to address all of its 548 interfaces, the IPv6 CE router SHOULD log a system management 549 error. [RFC6177] covers the recommendations for service 550 providers for prefix allocation sizes. 552 WPD-4: By default, the IPv6 CE router MUST initiate DHCPv6 prefix 553 delegation when either the M or O flags are set to 1 in a 554 received Router Advertisement (RA) message. Behavior of the 555 CE router to use DHCPv6 prefix delegation when the CE router 556 has not received any RA or received an RA with the M and the 557 O bits set to zero is out of scope for this document. 559 WPD-5: Any packet received by the CE router with a destination 560 address in the prefix(es) delegated to the CE router but not 561 in the set of prefixes assigned by the CE router to the LAN 562 must be dropped. In other words, the next hop for the 563 prefix(es) delegated to the CE router should be the null 564 destination. This is necessary to prevent forwarding loops 565 when some addresses covered by the aggregate are not 566 reachable [RFC4632]. 568 (a) The IPv6 CE router SHOULD send an ICMPv6 Destination 569 Unreachable message in accordance with Section 3.1 of 570 [RFC4443] back to the source of the packet, if the 571 packet is to be dropped due to this rule. 573 WPD-6: If the IPv6 CE router requests both an IA_NA and an IA_PD 574 option in DHCPv6, it MUST accept an IA_PD option in DHCPv6 575 Advertise/Reply messages, even if the message does not 576 contain any addresses, unless configured to only obtain its 577 WAN IPv6 address via DHCPv6; see [RFC7550]. 579 WPD-7: By default, an IPv6 CE router MUST NOT initiate any dynamic 580 routing protocol on its WAN interface. 582 WPD-8: The IPv6 CE router SHOULD support the [RFC6603] Prefix 583 Exclude option. 585 5.3. LAN-Side Configuration 587 The IPv6 CE router distributes configuration information obtained 588 during WAN interface provisioning to IPv6 hosts and assists IPv6 589 hosts in obtaining IPv6 addresses. It also supports connectivity of 590 these devices in the absence of any working WAN interface. 592 An IPv6 CE router is expected to support an IPv6 end-user network and 593 IPv6 hosts that exhibit the following characteristics: 595 1. Link-local addresses may be insufficient for allowing IPv6 596 applications to communicate with each other in the end-user 597 network. The IPv6 CE router will need to enable this 598 communication by providing globally scoped unicast addresses or 599 ULAs [RFC4193], whether or not WAN connectivity exists. 601 2. IPv6 hosts should be capable of using SLAAC and may be capable of 602 using DHCPv6 for acquiring their addresses. 604 3. IPv6 hosts may use DHCPv6 for other configuration information, 605 such as the DNS_SERVERS option for acquiring DNS information. 607 Unless otherwise specified, the following requirements apply to the 608 IPv6 CE router's LAN interfaces only. 610 ULA requirements: 612 ULA-1: The IPv6 CE router SHOULD be capable of generating a ULA 613 prefix [RFC4193]. 615 ULA-2: An IPv6 CE router with a ULA prefix MUST maintain this prefix 616 consistently across reboots. 618 ULA-3: The value of the ULA prefix SHOULD be configurable. 620 ULA-4: By default, the IPv6 CE router MUST act as a site border 621 router according to Section 4.3 of [RFC4193] and filter 622 packets with local IPv6 source or destination addresses 623 accordingly. 625 ULA-5: An IPv6 CE router MUST NOT advertise itself as a default 626 router with a Router Lifetime greater than zero whenever all 627 of its configured and delegated prefixes are ULA prefixes. 629 LAN requirements: 631 L-1: The IPv6 CE router MUST support router behavior according to 632 Neighbor Discovery for IPv6 [RFC4861]. 634 L-2: The IPv6 CE router MUST assign a separate /64 from its 635 delegated prefix(es) (and ULA prefix if configured to provide 636 ULA addressing) for each of its LAN interfaces. 638 L-3: An IPv6 CE router MUST advertise itself as a router for the 639 delegated prefix(es) (and ULA prefix if configured to provide 640 ULA addressing) using the "Route Information Option" specified 641 in Section 2.3 of [RFC4191]. This advertisement is 642 independent of having or not having IPv6 connectivity on the 643 WAN interface. 645 L-4: An IPv6 CE router MUST NOT advertise itself as a default 646 router with a Router Lifetime [RFC4861] greater than zero if 647 it has no prefixes configured or delegated to it. 649 L-5: The IPv6 CE router MUST make each LAN interface an advertising 650 interface according to [RFC4861]. 652 L-6: In Router Advertisement messages ([RFC4861]), the Prefix 653 Information option's A and L flags MUST be set to 1 by 654 default. 656 L-7: The A and L flags' ([RFC4861]) settings SHOULD be user 657 configurable. 659 L-8: The IPv6 CE router MUST support a DHCPv6 server capable of 660 IPv6 address assignment according to [RFC3315] OR a stateless 661 DHCPv6 server according to [RFC3736] on its LAN interfaces. 663 L-9: Unless the IPv6 CE router is configured to support the DHCPv6 664 IA_NA option, it SHOULD set the M flag to zero and the O flag 665 to 1 in its Router Advertisement messages [RFC4861]. 667 L-10: The IPv6 CE router MUST support providing DNS information in 668 the DHCPv6 DNS_SERVERS and DOMAIN_LIST options [RFC3646]. 670 L-11: The IPv6 CE router MUST support providing DNS information in 671 the Router Advertisement Recursive DNS Server (RDNSS) and DNS 672 Search List options. Both options are specified in [RFC6106]. 674 L-12: The IPv6 CE router SHOULD implement a DNS proxy as described 675 in [RFC5625]. 677 L-13: The IPv6 CE router SHOULD make available a subset of DHCPv6 678 options (as listed in Section 5.3 of [RFC3736]) received from 679 the DHCPv6 client on its WAN interface to its LAN-side DHCPv6 680 server. 682 L-14: If the delegated prefix changes, i.e., the current prefix is 683 replaced with a new prefix without any overlapping time 684 period, then the IPv6 CE router MUST immediately advertise the 685 old prefix with a Preferred Lifetime of zero and a Valid 686 Lifetime of either a) zero or b) the lower of the current 687 Valid Lifetime and two hours (which must be decremented in 688 real time) in a Router Advertisement message as described in 689 Section 5.5.3, (e) of [RFC4862]. 691 L-15: The IPv6 CE router MUST send an ICMPv6 Destination Unreachable 692 message, code 5 (Source address failed ingress/egress policy) 693 for packets forwarded to it that use an address from a prefix 694 that has been invalidated. 696 L-16: The IPv6 CE router SHOULD provide HNCP (Home Networking 697 Control Protocol) services, as specified in [RFC7788]. 699 5.4. Transition Technologies Support 701 Even if the main target of this document is the support of IPv6-only 702 WAN access, for some time, there will be a need to support IPv4-only 703 devices and applications in the customers LANs, in one side of the 704 picture. In the other side, some Service Providers willing to deploy 705 IPv6, may not be able to do so in the first stage, neither as 706 IPv6-only or dual-stack in the WAN. Consequently, transition 707 technologies to resolve both issues should be taken in consideration. 709 5.4.1. IPv4 Service Continuity in Customer LANs 711 5.4.1.1. 464XLAT 713 464XLAT [RFC6877] is a technique to provide IPv4 access service to 714 IPv6-only edge networks without encapsulation. 716 The CE router SHOULD support CLAT functionality. If 464XLAT is 717 supported, it MUST be implemented according to [RFC6877]. The 718 following CE Requirements also apply: 720 464XLAT requirements: 722 464XLAT-1: The IPv6 CE router MUST perform IPv4 Network Address 723 Translation (NAT) on IPv4 traffic translated using the 724 CLAT, unless a dedicated /64 prefix has been acquired 725 using DHCPv6-PD [RFC3633]. 727 464XLAT-2: The CE router MUST implement [RFC7050] in order to 728 discover the PLAT-side translation IPv4 and IPv6 729 prefix(es)/suffix(es). In environments with PCP support, 730 the CE SHOULD follow [RFC7225] to learn the PLAT-side 731 translation IPv4 and IPv6 prefix(es)/suffix(es) used by 732 an upstream PCP-controlled NAT64 device. 734 5.4.1.2. Dual-Stack Lite (DS-Lite) 736 Dual-Stack Lite [RFC6333] enables both continued support for IPv4 737 services and incentives for the deployment of IPv6. It also 738 de-couples IPv6 deployment in the service provider network from the 739 rest of the Internet, making incremental deployment easier. Dual- 740 Stack Lite enables a broadband service provider to share IPv4 741 addresses among customers by combining two well-known technologies: 742 IP in IP (IPv4-in-IPv6) and Network Address Translation (NAT). It is 743 expected that DS-Lite traffic is forwarded over the CE router's 744 native IPv6 WAN interface, and not encapsulated in another tunnel. 746 The IPv6 CE router SHOULD implement DS-Lite functionality. If 747 DS-Lite is supported, it MUST be implemented according to [RFC6333]. 748 This document takes no position on simultaneous operation of Dual- 749 Stack Lite and native IPv4. The following CE router requirements 750 also apply: 752 DS-Lite requirements: 754 DSLITE-1: The CE router MUST support configuration of DS-Lite via 755 the DS-Lite DHCPv6 option [RFC6334]. The IPv6 CE router 756 MAY use other mechanisms to configure DS-Lite parameters. 758 Such mechanisms are outside the scope of this document. 760 DSLITE-2: The CE router MUST support the DHCPv6 S46 priority option 761 described in [RFC8026]. 763 DSLITE-3: The IPv6 CE router MUST NOT perform IPv4 Network Address 764 Translation (NAT) on IPv4 traffic encapsulated using DS- 765 Lite. 767 DSLITE-4: If the IPv6 CE router is configured with an IPv4 address 768 on its WAN interface, then the IPv6 CE router SHOULD 769 disable the DS-Lite Basic Bridging BroadBand (B4) element. 771 5.4.1.3. Lightweight 4over6 (lw4o6) 773 Lw4o6 [RFC7596] specifies an extension to DS-Lite, which moves the 774 NAPT function from the DS-Lite tunnel concentrator to the tunnel 775 client located in the IPv6 CE router, removing the requirement for a 776 CGN function in the tunnel concentrator and reducing the amount of 777 centralized state. 779 The IPv6 CE router SHOULD implement lw4o6 functionality. If DS-Lite 780 is implemented, lw4o6 MUST be supported as well. If lw4o6 is 781 supported, it MUST be implemented according to [RFC7596]. This 782 document takes no position on simultaneous operation of lw4o6 and 783 native IPv4. The following CE router Requirements also apply: 785 Lw4o6 requirements: 787 LW4O6-1: The CE router MUST support configuration of lw4o6 via the 788 lw4o6 DHCPv6 options [RFC7598]. The IPv6 CE router MAY use 789 other mechanisms to configure lw4o6 parameters. Such 790 mechanisms are outside the scope of this document. 792 LW4O6-2: The CE router MUST support the DHCPv6 S46 priority option 793 described in [RFC8026]. 795 LW4O6-3: The CE router MUST support the DHCPv4-over-DHCPv6 (DHCP 796 4o6) transport described in [RFC7341]. 798 LW4O6-4: The CE router MAY support Dynamic Allocation of Shared IPv4 799 Addresses as described in [RFC7618]. 801 5.4.1.4. MAP-E 803 MAP-E [RFC7597] is a mechanism for transporting IPv4 packets across 804 an IPv6 network using IP encapsulation, including a generic mechanism 805 for mapping between IPv6 addresses and IPv4 addresses as well as 806 transport-layer ports. 808 The CE router SHOULD support MAP-E functionality. If MAP-E is 809 supported, it MUST be implemented according to [RFC7597]. The 810 following CE Requirements also apply: 812 MAP-E requirements: 814 MAPE-1: The CE router MUST support configuration of MAP-E via the 815 MAP-E DHCPv6 options [RFC7598]. The IPv6 CE router MAY use 816 other mechanisms to configure MAP-E parameters. Such 817 mechanisms are outside the scope of this document. 819 MAPE-2: The CE router MUST support the DHCPv6 S46 priority option 820 described in [RFC8026]. 822 5.4.1.5. MAP-T 824 MAP-T [RFC7599] is a mechanism similar to MAP-E, differing from it in 825 that MAP-T uses IPv4-IPv6 translation, rather than encapsulation, as 826 the form of IPv6 domain transport. 828 The CE router SHOULD support MAP-T functionality. If MAP-T is 829 supported, it MUST be implemented according to [RFC7599]. The 830 following CE Requirements also apply: 832 MAP-T requirements: 834 MAPT-1: The CE router MUST support configuration of MAP-T via the 835 MAP-E DHCPv6 options [RFC7598]. The IPv6 CE router MAY use 836 other mechanisms to configure MAP-E parameters. Such 837 mechanisms are outside the scope of this document. 839 MAPT-2: The CE router MUST support the DHCPv6 S46 priority option 840 described in [RFC8026]. 842 5.4.2. Support of IPv6 in IPv4-only WAN access 844 5.4.2.1. 6in4 846 6in4 [RFC4213] specifies a tunneling mechanism to allow end-users to 847 manually configure IPv6 support via a service provider's IPv4 network 848 infrastructure. 850 The CE router MAY support 6in4 functionality. 6in4 used for a 851 manually configured tunnel requires a subset of the 6rd parameters 852 (delegated prefix and remote IPv4 end-point). The on-wire and 853 forwarding plane is identical for both mechanisms, however 6in4 854 doesn't support mesh traffic and requires manually provisioning. 855 Thus, if the device supports either 6rd or 6in4, it's commonly a 856 minor UI addition to support both. If 6in4 is supported, it MUST be 857 implemented according to [RFC4213]. The following CE Requirements 858 also apply: 860 6in4 requirements: 862 6IN4-1: The IPv6 CE router SHOULD support 6in4 automated 863 configuration by means of the 6rd DHCPv4 Option 212. If the 864 CE router has obtained an IPv4 network address through some 865 other means such as PPP, it SHOULD use the DHCPINFORM 866 request message [RFC2131] to request the 6rd DHCPv4 Option. 867 The IPv6 CE router MAY use other mechanisms to configure 868 6in4 parameters. Such mechanisms are outside the scope of 869 this document. 871 6IN4-2: If the IPv6 CE router is capable of automated configuration 872 of IPv4 through IPCP (i.e., over a PPP connection), it MUST 873 support user-entered configuration of 6in4. 875 6IN4-3: If the CE router supports configuration mechanisms other 876 than the 6rd DHCPv4 Option 212 (user-entered, TR-069 877 [TR-069], etc.), the CE router MUST support 6in4 in "hub and 878 spoke" mode. 6in4 in "hub and spoke" requires all IPv6 879 traffic to go to the 6rd Border Relay, which in this case is 880 the tunnel-end-point. In effect, this requirement removes 881 the "direct connect to 6rd" route defined in Section 7.1.1 882 of [RFC5969]. 884 6IN4-4: A CE router MUST allow 6in4 and native IPv6 WAN interfaces 885 to be active alone as well as simultaneously in order to 886 support coexistence of the two technologies during an 887 incremental transition period such as a transition from 6in4 888 to native IPv6. 890 6IN4-5: Each packet sent on a 6in4 or native WAN interface MUST be 891 directed such that its source IP address is derived from the 892 delegated prefix associated with the particular interface 893 from which the packet is being sent (Section 4.3 of 894 [RFC3704]). 896 6IN4-6: The CE router MUST allow different as well as identical 897 delegated prefixes to be configured via each (6in4 or 898 native) WAN interface. 900 6IN4-7: In the event that forwarding rules produce a tie between 901 6in4 and native IPv6, by default, the IPv6 CE router MUST 902 prefer native IPv6. 904 5.4.2.2. 6rd 906 6rd [RFC5969] specifies an automatic tunneling mechanism tailored to 907 advance deployment of IPv6 to end users via a service provider's IPv4 908 network infrastructure. Key aspects include automatic IPv6 prefix 909 delegation to sites, stateless operation, simple provisioning, and 910 service that is equivalent to native IPv6 at the sites that are 911 served by the mechanism. It is expected that such traffic is 912 forwarded over the CE router's native IPv4 WAN interface and not 913 encapsulated in another tunnel. 915 The CE router MAY support 6rd functionality. If 6rd is supported, it 916 MUST be implemented according to [RFC5969]. The following CE 917 Requirements also apply: 919 6rd requirements: 921 6RD-1: The IPv6 CE router MUST support 6rd configuration via the 6rd 922 DHCPv4 Option 212. If the CE router has obtained an IPv4 923 network address through some other means such as PPP, it 924 SHOULD use the DHCPINFORM request message [RFC2131] to 925 request the 6rd DHCPv4 Option. The IPv6 CE router MAY use 926 other mechanisms to configure 6rd parameters. Such 927 mechanisms are outside the scope of this document. 929 6RD-2: If the IPv6 CE router is capable of automated configuration 930 of IPv4 through IPCP (i.e., over a PPP connection), it MUST 931 support user-entered configuration of 6rd. 933 6RD-3: If the CE router supports configuration mechanisms other than 934 the 6rd DHCPv4 Option 212 (user-entered, TR-069 [TR-069], 935 etc.), the CE router MUST support 6rd in "hub and spoke" 936 mode. 6rd in "hub and spoke" requires all IPv6 traffic to go 937 to the 6rd Border Relay. In effect, this requirement removes 938 the "direct connect to 6rd" route defined in Section 7.1.1 of 939 [RFC5969]. 941 6RD-4: A CE router MUST allow 6rd and native IPv6 WAN interfaces to 942 be active alone as well as simultaneously in order to support 943 coexistence of the two technologies during an incremental 944 transition period such as a transition from 6rd to native 945 IPv6. 947 6RD-5: Each packet sent on a 6rd or native WAN interface MUST be 948 directed such that its source IP address is derived from the 949 delegated prefix associated with the particular interface 950 from which the packet is being sent (Section 4.3 of 951 [RFC3704]). 953 6RD-6: The CE router MUST allow different as well as identical 954 delegated prefixes to be configured via each (6rd or native) 955 WAN interface. 957 6RD-7: In the event that forwarding rules produce a tie between 6rd 958 and native IPv6, by default, the IPv6 CE router MUST prefer 959 native IPv6. 961 5.5. IPv4 Multicast Support 963 Actual deployments support IPv4 multicast for services such as IPTV. 964 In the transition phase it is expected that multicast services will 965 still be provided using IPv4 to the customer LANs. 967 In order to support the delivery of IPv4 multicast services to IPv4 968 clients over an IPv6 multicast network, the CE router SHOULD support 969 [RFC8114] and [RFC8115]. 971 5.6. Security Considerations 973 It is considered a best practice to filter obviously malicious 974 traffic (e.g., spoofed packets, "Martian" addresses, etc.). Thus, 975 the IPv6 CE router ought to support basic stateless egress and 976 ingress filters. The CE router is also expected to offer mechanisms 977 to filter traffic entering the customer network; however, the method 978 by which vendors implement configurable packet filtering is beyond 979 the scope of this document. 981 Security requirements: 983 S-1: The IPv6 CE router SHOULD support [RFC6092]. In particular, 984 the IPv6 CE router SHOULD support functionality sufficient for 985 implementing the set of recommendations in [RFC6092], 986 Section 4. This document takes no position on whether such 987 functionality is enabled by default or mechanisms by which 988 users would configure it. 990 S-2: The IPv6 CE router SHOULD support ingress filtering in 991 accordance with BCP 38 [RFC2827]. Note that this requirement 992 was downgraded from a MUST from RFC 6204 due to the difficulty 993 of implementation in the CE router and the feature's redundancy 994 with upstream router ingress filtering. 996 S-3: If the IPv6 CE router firewall is configured to filter incoming 997 tunneled data, the firewall SHOULD provide the capability to 998 filter decapsulated packets from a tunnel. 1000 6. Acknowledgements 1002 Thanks to James Woodyatt, Mohamed Boucadair, Masanobu Kawashima, 1003 Mikael Abrahamsson, Barbara Stark and Ole Troan for their review and 1004 comments. 1006 This document is an update of RFC7084, whose original authors were: 1007 Hemant Singh, Wes Beebee, Chris Donley and Barbara Stark. The rest 1008 of the text on this section and the Contributors section, are the 1009 original acknowledgements and Contributors sections of the earlier 1010 version of this document. 1012 Thanks to the following people (in alphabetical order) for their 1013 guidance and feedback: 1015 Mikael Abrahamsson, Tore Anderson, Merete Asak, Rajiv Asati, Scott 1016 Beuker, Mohamed Boucadair, Rex Bullinger, Brian Carpenter, Tassos 1017 Chatzithomaoglou, Lorenzo Colitti, Remi Denis-Courmont, Gert Doering, 1018 Alain Durand, Katsunori Fukuoka, Brian Haberman, Tony Hain, Thomas 1019 Herbst, Ray Hunter, Joel Jaeggli, Kevin Johns, Erik Kline, Stephen 1020 Kramer, Victor Kuarsingh, Francois-Xavier Le Bail, Arifumi Matsumoto, 1021 David Miles, Shin Miyakawa, Jean-Francois Mule, Michael Newbery, 1022 Carlos Pignataro, John Pomeroy, Antonio Querubin, Daniel Roesen, 1023 Hiroki Sato, Teemu Savolainen, Matt Schmitt, David Thaler, Mark 1024 Townsley, Sean Turner, Bernie Volz, Dan Wing, Timothy Winters, James 1025 Woodyatt, Carl Wuyts, and Cor Zwart. 1027 This document is based in part on CableLabs' eRouter specification. 1028 The authors wish to acknowledge the additional contributors from the 1029 eRouter team: 1031 Ben Bekele, Amol Bhagwat, Ralph Brown, Eduardo Cardona, Margo Dolas, 1032 Toerless Eckert, Doc Evans, Roger Fish, Michelle Kuska, Diego 1033 Mazzola, John McQueen, Harsh Parandekar, Michael Patrick, Saifur 1034 Rahman, Lakshmi Raman, Ryan Ross, Ron da Silva, Madhu Sudan, Dan 1035 Torbet, and Greg White. 1037 7. Contributors 1039 The following people have participated as co-authors or provided 1040 substantial contributions to this document: Ralph Droms, Kirk 1041 Erichsen, Fred Baker, Jason Weil, Lee Howard, Jean-Francois Tremblay, 1042 Yiu Lee, John Jason Brzozowski, and Heather Kirksey. Thanks to Ole 1043 Troan for editorship in the original RFC 6204 document. 1045 8. ANNEX A: Code Considerations 1047 One of the apparent main issues for vendors to include new 1048 functionalities, such as support for new transition mechanisms, is 1049 the lack of space in the flash (or equivalent) memory. However, it 1050 has been confirmed from existing open source implementations 1051 (OpenWRT/LEDE), that adding the support for the new transitions 1052 mechanisms, requires around 10-12 Kbytes (because most of the code is 1053 shared among several transition mechanisms), which typically means 1054 about 0,15% of the existing code size in popular CEs in the market. 1056 It is also clear that the new requirements don't have extra cost in 1057 terms of RAM memory, neither other hardware requirements such as more 1058 powerful CPUs. 1060 The other issue seems to be the cost of developing the code for those 1061 new functionalities. However at the time of writing this document, 1062 it has been confirmed that there are several open source versions of 1063 the required code for supporting the new transition mechanisms, so 1064 the development cost is negligent, and only integration and testing 1065 cost may become a minor issue. 1067 9. ANNEX B: Changes from RFC7084 1069 The -bis version of this document has some minor text edits here and 1070 there. Significant updates are: 1072 1. New section "Usage Scenarios". 1074 2. Added support of HNCP ([RFC7788]) in LAN (L-16). 1076 3. Added support of 464XLAT ([RFC6877]). 1078 4. Added support of lw4o6 ([RFC7596]). 1080 5. Added support of MAP-E ([RFC7597]) and MAP-T ([RFC7599]). 1082 6. As the main scope of this document is the IPv6-only CE (IPv6-only 1083 in the WAN link), the support of 6rd ([RFC5969]) has been changed 1084 to MAY. 6in4 ([RFC4213]) support has been included as well in 1085 case 6rd is supported, as it doesn't require additional code. 1087 7. New section "IPv4 Multicast Support". 1089 8. Added support for DNS proxy [RFC5625] as general LAN requirement. 1091 9. Split of transition in two sub-sections for the sake of clarity. 1093 10. ANNEX C: Changes from RFC7084-bis-00 1095 Section to be removed for WGLC. Significant updates are: 1097 1. LW4O6-5 changed to port-restricted to conform with [RFC7596]. 1099 2. MAPE-3 changed to port-restricted to conform with [RFC7597]. 1101 3. MAPT-3 changed to port-restricted to conform with [RFC7599]. 1103 4. [RFC7341] removed from 464XLAT, DS-LITE, MAP-E and MAP-T 1104 requirements. 1106 5. [RFC5625] removed from 464XLAT, and included as general LAN 1107 requirement. 1109 6. [RFC7618] included as MAY for lw4o6. 1111 7. 6in4 text clarifications. 1113 8. Included non-normative reference to [RFC7849] to clarify that the 1114 details of the connectivity to 3GPP/LTE networks is out of the 1115 scope. 1117 9. Split of transition in two sub-sections for the sake of clarity. 1119 11. ANNEX D: Changes from RFC7084-bis-01 1121 Section to be removed for WGLC. Significant updates are: 1123 1. G-5 added in order to comply with [RFC7608]. 1125 2. LW4O6-5 removed. 1127 3. MAPE-3 removed. 1129 4. MAPT-3 removed. 1131 5. Included non-normative reference to [RFC7849] to clarify that the 1132 details of the connectivity to 3GPP/LTE networks is out of the 1133 scope. 1135 6. Split of transition in two sub-sections for the sake of clarity. 1137 12. ANNEX E: Changes from RFC7084-bis-02 1139 Section to be removed for WGLC. Significant updates are: 1141 1. LW4O6-5 removed, was a mistake due to copy-paste from DS-LITE. 1143 2. Removed citation to individual I-Ds for DHCPv6 options. 1145 13. References 1147 13.1. Normative References 1149 [RFC1122] Braden, R., Ed., "Requirements for Internet Hosts - 1150 Communication Layers", STD 3, RFC 1122, 1151 DOI 10.17487/RFC1122, October 1989, 1152 . 1154 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1155 Requirement Levels", BCP 14, RFC 2119, 1156 DOI 10.17487/RFC2119, March 1997, 1157 . 1159 [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", 1160 RFC 2131, DOI 10.17487/RFC2131, March 1997, 1161 . 1163 [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet 1164 Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, 1165 . 1167 [RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering: 1168 Defeating Denial of Service Attacks which employ IP Source 1169 Address Spoofing", BCP 38, RFC 2827, DOI 10.17487/RFC2827, 1170 May 2000, . 1172 [RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, 1173 C., and M. Carney, "Dynamic Host Configuration Protocol 1174 for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July 1175 2003, . 1177 [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic 1178 Host Configuration Protocol (DHCP) version 6", RFC 3633, 1179 DOI 10.17487/RFC3633, December 2003, 1180 . 1182 [RFC3646] Droms, R., Ed., "DNS Configuration options for Dynamic 1183 Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3646, 1184 DOI 10.17487/RFC3646, December 2003, 1185 . 1187 [RFC3704] Baker, F. and P. Savola, "Ingress Filtering for Multihomed 1188 Networks", BCP 84, RFC 3704, DOI 10.17487/RFC3704, March 1189 2004, . 1191 [RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol 1192 (DHCP) Service for IPv6", RFC 3736, DOI 10.17487/RFC3736, 1193 April 2004, . 1195 [RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and 1196 More-Specific Routes", RFC 4191, DOI 10.17487/RFC4191, 1197 November 2005, . 1199 [RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast 1200 Addresses", RFC 4193, DOI 10.17487/RFC4193, October 2005, 1201 . 1203 [RFC4213] Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms 1204 for IPv6 Hosts and Routers", RFC 4213, 1205 DOI 10.17487/RFC4213, October 2005, 1206 . 1208 [RFC4242] Venaas, S., Chown, T., and B. Volz, "Information Refresh 1209 Time Option for Dynamic Host Configuration Protocol for 1210 IPv6 (DHCPv6)", RFC 4242, DOI 10.17487/RFC4242, November 1211 2005, . 1213 [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet 1214 Control Message Protocol (ICMPv6) for the Internet 1215 Protocol Version 6 (IPv6) Specification", RFC 4443, 1216 DOI 10.17487/RFC4443, March 2006, 1217 . 1219 [RFC4605] Fenner, B., He, H., Haberman, B., and H. Sandick, 1220 "Internet Group Management Protocol (IGMP) / Multicast 1221 Listener Discovery (MLD)-Based Multicast Forwarding 1222 ("IGMP/MLD Proxying")", RFC 4605, DOI 10.17487/RFC4605, 1223 August 2006, . 1225 [RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing 1226 (CIDR): The Internet Address Assignment and Aggregation 1227 Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August 1228 2006, . 1230 [RFC4779] Asadullah, S., Ahmed, A., Popoviciu, C., Savola, P., and 1231 J. Palet, "ISP IPv6 Deployment Scenarios in Broadband 1232 Access Networks", RFC 4779, DOI 10.17487/RFC4779, January 1233 2007, . 1235 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 1236 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 1237 DOI 10.17487/RFC4861, September 2007, 1238 . 1240 [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless 1241 Address Autoconfiguration", RFC 4862, 1242 DOI 10.17487/RFC4862, September 2007, 1243 . 1245 [RFC5072] Varada, S., Ed., Haskins, D., and E. Allen, "IP Version 6 1246 over PPP", RFC 5072, DOI 10.17487/RFC5072, September 2007, 1247 . 1249 [RFC5625] Bellis, R., "DNS Proxy Implementation Guidelines", 1250 BCP 152, RFC 5625, DOI 10.17487/RFC5625, August 2009, 1251 . 1253 [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, 1254 "Network Time Protocol Version 4: Protocol and Algorithms 1255 Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, 1256 . 1258 [RFC5908] Gayraud, R. and B. Lourdelet, "Network Time Protocol (NTP) 1259 Server Option for DHCPv6", RFC 5908, DOI 10.17487/RFC5908, 1260 June 2010, . 1262 [RFC5942] Singh, H., Beebee, W., and E. Nordmark, "IPv6 Subnet 1263 Model: The Relationship between Links and Subnet 1264 Prefixes", RFC 5942, DOI 10.17487/RFC5942, July 2010, 1265 . 1267 [RFC5969] Townsley, W. and O. Troan, "IPv6 Rapid Deployment on IPv4 1268 Infrastructures (6rd) -- Protocol Specification", 1269 RFC 5969, DOI 10.17487/RFC5969, August 2010, 1270 . 1272 [RFC6092] Woodyatt, J., Ed., "Recommended Simple Security 1273 Capabilities in Customer Premises Equipment (CPE) for 1274 Providing Residential IPv6 Internet Service", RFC 6092, 1275 DOI 10.17487/RFC6092, January 2011, 1276 . 1278 [RFC6106] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli, 1279 "IPv6 Router Advertisement Options for DNS Configuration", 1280 RFC 6106, DOI 10.17487/RFC6106, November 2010, 1281 . 1283 [RFC6177] Narten, T., Huston, G., and L. Roberts, "IPv6 Address 1284 Assignment to End Sites", BCP 157, RFC 6177, 1285 DOI 10.17487/RFC6177, March 2011, 1286 . 1288 [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- 1289 Stack Lite Broadband Deployments Following IPv4 1290 Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011, 1291 . 1293 [RFC6334] Hankins, D. and T. Mrugalski, "Dynamic Host Configuration 1294 Protocol for IPv6 (DHCPv6) Option for Dual-Stack Lite", 1295 RFC 6334, DOI 10.17487/RFC6334, August 2011, 1296 . 1298 [RFC6434] Jankiewicz, E., Loughney, J., and T. Narten, "IPv6 Node 1299 Requirements", RFC 6434, DOI 10.17487/RFC6434, December 1300 2011, . 1302 [RFC6603] Korhonen, J., Ed., Savolainen, T., Krishnan, S., and O. 1303 Troan, "Prefix Exclude Option for DHCPv6-based Prefix 1304 Delegation", RFC 6603, DOI 10.17487/RFC6603, May 2012, 1305 . 1307 [RFC6877] Mawatari, M., Kawashima, M., and C. Byrne, "464XLAT: 1308 Combination of Stateful and Stateless Translation", 1309 RFC 6877, DOI 10.17487/RFC6877, April 2013, 1310 . 1312 [RFC6887] Wing, D., Ed., Cheshire, S., Boucadair, M., Penno, R., and 1313 P. Selkirk, "Port Control Protocol (PCP)", RFC 6887, 1314 DOI 10.17487/RFC6887, April 2013, 1315 . 1317 [RFC7050] Savolainen, T., Korhonen, J., and D. Wing, "Discovery of 1318 the IPv6 Prefix Used for IPv6 Address Synthesis", 1319 RFC 7050, DOI 10.17487/RFC7050, November 2013, 1320 . 1322 [RFC7083] Droms, R., "Modification to Default Values of SOL_MAX_RT 1323 and INF_MAX_RT", RFC 7083, DOI 10.17487/RFC7083, November 1324 2013, . 1326 [RFC7225] Boucadair, M., "Discovering NAT64 IPv6 Prefixes Using the 1327 Port Control Protocol (PCP)", RFC 7225, 1328 DOI 10.17487/RFC7225, May 2014, 1329 . 1331 [RFC7341] Sun, Q., Cui, Y., Siodelski, M., Krishnan, S., and I. 1332 Farrer, "DHCPv4-over-DHCPv6 (DHCP 4o6) Transport", 1333 RFC 7341, DOI 10.17487/RFC7341, August 2014, 1334 . 1336 [RFC7596] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I. 1337 Farrer, "Lightweight 4over6: An Extension to the Dual- 1338 Stack Lite Architecture", RFC 7596, DOI 10.17487/RFC7596, 1339 July 2015, . 1341 [RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S., 1342 Murakami, T., and T. Taylor, Ed., "Mapping of Address and 1343 Port with Encapsulation (MAP-E)", RFC 7597, 1344 DOI 10.17487/RFC7597, July 2015, 1345 . 1347 [RFC7598] Mrugalski, T., Troan, O., Farrer, I., Perreault, S., Dec, 1348 W., Bao, C., Yeh, L., and X. Deng, "DHCPv6 Options for 1349 Configuration of Softwire Address and Port-Mapped 1350 Clients", RFC 7598, DOI 10.17487/RFC7598, July 2015, 1351 . 1353 [RFC7599] Li, X., Bao, C., Dec, W., Ed., Troan, O., Matsushima, S., 1354 and T. Murakami, "Mapping of Address and Port using 1355 Translation (MAP-T)", RFC 7599, DOI 10.17487/RFC7599, July 1356 2015, . 1358 [RFC7608] Boucadair, M., Petrescu, A., and F. Baker, "IPv6 Prefix 1359 Length Recommendation for Forwarding", BCP 198, RFC 7608, 1360 DOI 10.17487/RFC7608, July 2015, 1361 . 1363 [RFC7618] Cui, Y., Sun, Q., Farrer, I., Lee, Y., Sun, Q., and M. 1364 Boucadair, "Dynamic Allocation of Shared IPv4 Addresses", 1365 RFC 7618, DOI 10.17487/RFC7618, August 2015, 1366 . 1368 [RFC7788] Stenberg, M., Barth, S., and P. Pfister, "Home Networking 1369 Control Protocol", RFC 7788, DOI 10.17487/RFC7788, April 1370 2016, . 1372 [RFC8026] Boucadair, M. and I. Farrer, "Unified IPv4-in-IPv6 1373 Softwire Customer Premises Equipment (CPE): A DHCPv6-Based 1374 Prioritization Mechanism", RFC 8026, DOI 10.17487/RFC8026, 1375 November 2016, . 1377 [RFC8114] Boucadair, M., Qin, C., Jacquenet, C., Lee, Y., and Q. 1378 Wang, "Delivery of IPv4 Multicast Services to IPv4 Clients 1379 over an IPv6 Multicast Network", RFC 8114, 1380 DOI 10.17487/RFC8114, March 2017, 1381 . 1383 [RFC8115] Boucadair, M., Qin, J., Tsou, T., and X. Deng, "DHCPv6 1384 Option for IPv4-Embedded Multicast and Unicast IPv6 1385 Prefixes", RFC 8115, DOI 10.17487/RFC8115, March 2017, 1386 . 1388 13.2. Informative References 1390 [RFC7157] Troan, O., Ed., Miles, D., Matsushima, S., Okimoto, T., 1391 and D. Wing, "IPv6 Multihoming without Network Address 1392 Translation", RFC 7157, DOI 10.17487/RFC7157, March 2014, 1393 . 1395 [RFC7550] Troan, O., Volz, B., and M. Siodelski, "Issues and 1396 Recommendations with Multiple Stateful DHCPv6 Options", 1397 RFC 7550, DOI 10.17487/RFC7550, May 2015, 1398 . 1400 [RFC7849] Binet, D., Boucadair, M., Vizdal, A., Chen, G., Heatley, 1401 N., Chandler, R., Michaud, D., Lopez, D., and W. Haeffner, 1402 "An IPv6 Profile for 3GPP Mobile Devices", RFC 7849, 1403 DOI 10.17487/RFC7849, May 2016, 1404 . 1406 [TR-069] Broadband Forum, "CPE WAN Management Protocol", TR-069 1407 Amendment 4, July 2011, 1408 . 1410 [UPnP-IGD] 1411 UPnP Forum, "InternetGatewayDevice:2 Device Template 1412 Version 1.01", December 2010, 1413 . 1415 Author's Address 1416 Jordi Palet Martinez 1417 Consulintel, S.L. 1418 Molino de la Navata, 75 1419 La Navata - Galapagar, Madrid 28420 1420 Spain 1422 EMail: jordi.palet@consulintel.es 1423 URI: http://www.consulintel.es/