From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc7084.txt | 1179 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1179 insertions(+) create mode 100644 doc/rfc/rfc7084.txt (limited to 'doc/rfc/rfc7084.txt') diff --git a/doc/rfc/rfc7084.txt b/doc/rfc/rfc7084.txt new file mode 100644 index 0000000..ba07671 --- /dev/null +++ b/doc/rfc/rfc7084.txt @@ -0,0 +1,1179 @@ + + + + + + +Internet Engineering Task Force (IETF) H. Singh +Request for Comments: 7084 W. Beebee +Obsoletes: 6204 Cisco Systems, Inc. +Category: Informational C. Donley +ISSN: 2070-1721 CableLabs + B. Stark + AT&T + November 2013 + + + Basic Requirements for IPv6 Customer Edge Routers + +Abstract + + This document specifies requirements for an IPv6 Customer Edge (CE) + router. Specifically, the current version of this document focuses + on the basic provisioning of an IPv6 CE router and the provisioning + of IPv6 hosts attached to it. The document also covers IP transition + technologies. Two transition technologies in RFC 5969's IPv6 Rapid + Deployment on IPv4 Infrastructures (6rd) and RFC 6333's Dual-Stack + Lite (DS-Lite) are covered in the document. The document obsoletes + RFC 6204. + +Status of This Memo + + This document is not an Internet Standards Track specification; it is + published for informational purposes. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Not all documents + approved by the IESG are a candidate for any level of Internet + Standard; see Section 2 of RFC 5741. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc7084. + + + + + + + + + + + + + +Singh, et al. Informational [Page 1] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + +Copyright Notice + + Copyright (c) 2013 IETF Trust and the persons identified as the + document authors. All rights reserved. + + This document is subject to BCP 78 and the IETF Trust's Legal + Provisions Relating to IETF Documents + (http://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + +Table of Contents + + 1. Introduction ....................................................3 + 1.1. Requirements Language ......................................3 + 2. Terminology .....................................................4 + 3. Architecture ....................................................5 + 3.1. Current IPv4 End-User Network Architecture .................5 + 3.2. IPv6 End-User Network Architecture .........................5 + 3.2.1. Local Communication .................................7 + 4. Requirements ....................................................7 + 4.1. General Requirements .......................................7 + 4.2. WAN-Side Configuration .....................................8 + 4.3. LAN-Side Configuration ....................................12 + 4.4. Transition Technologies Support ...........................14 + 4.4.1. 6rd ................................................14 + 4.4.2. Dual-Stack Lite (DS-Lite) ..........................15 + 4.5. Security Considerations ...................................16 + 5. Acknowledgements ...............................................17 + 6. Contributors ...................................................17 + 7. References .....................................................18 + 7.1. Normative References ......................................18 + 7.2. Informative References ....................................20 + + + + + + + + + + + + + + +Singh, et al. Informational [Page 2] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + +1. Introduction + + This document defines basic IPv6 features for a residential or small- + office router, referred to as an "IPv6 CE router", in order to + establish an industry baseline for features to be implemented on such + a router. + + These routers typically also support IPv4. + + Mixed environments of dual-stack hosts and IPv6-only hosts (behind + the CE router) can be more complex if the IPv6-only devices are using + a translator to access IPv4 servers [RFC6144]. Support for such + mixed environments is not in scope of this document. + + This document specifies how an IPv6 CE router automatically + provisions its WAN interface, acquires address space for provisioning + of its LAN interfaces, and fetches other configuration information + from the service provider network. Automatic provisioning of more + complex topology than a single router with multiple LAN interfaces is + out of scope for this document. + + See [RFC4779] for a discussion of options available for deploying + IPv6 in service provider access networks. + + The document also covers the IP transition technologies that were + available at the time this document was written. Two transition + technologies in 6rd [RFC5969] and DS-Lite [RFC6333] are covered in + the document. + +1.1. Requirements Language + + Take careful note: Unlike other IETF documents, the key words "MUST", + "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", + "RECOMMENDED", "MAY", and "OPTIONAL" in this document are not used as + described in RFC 2119 [RFC2119]. This document uses these keywords + not strictly for the purpose of interoperability, but rather for the + purpose of establishing industry-common baseline functionality. As + such, the document points to several other specifications (preferable + in RFC or stable form) to provide additional guidance to implementers + regarding any protocol implementation required to produce a + successful CE router that interoperates successfully with a + particular subset of currently deploying and planned common IPv6 + access networks. + + + + + + + + +Singh, et al. Informational [Page 3] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + +2. Terminology + + End-User Network one or more links attached to the IPv6 CE + router that connect IPv6 hosts. + + IPv6 Customer Edge Router a node intended for home or small-office + use that forwards IPv6 packets not + explicitly addressed to itself. The IPv6 + CE router connects the end-user network to + a service provider network. + + IPv6 Host any device implementing an IPv6 stack + receiving IPv6 connectivity through the + IPv6 CE router. + + LAN Interface an IPv6 CE router's attachment to a link in + the end-user network. Examples are + Ethernet (simple or bridged), 802.11 + wireless, or other LAN technologies. An + IPv6 CE router may have one or more + network-layer LAN interfaces. + + Service Provider an entity that provides access to the + Internet. In this document, a service + provider specifically offers Internet + access using IPv6, and it may also offer + IPv4 Internet access. The service provider + can provide such access over a variety of + different transport methods such as DSL, + cable, wireless, and others. + + WAN Interface an IPv6 CE router's attachment to a link + used to provide connectivity to the service + provider network; example link technologies + include Ethernet (simple or bridged), PPP + links, Frame Relay, or ATM networks, as + well as Internet-layer (or higher-layer) + "tunnels", such as tunnels over IPv4 or + IPv6 itself. + + + + + + + + + + + + +Singh, et al. Informational [Page 4] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + +3. Architecture + +3.1. Current IPv4 End-User Network Architecture + + An end-user network will likely support both IPv4 and IPv6. It is + not expected that an end user will change their existing network + topology with the introduction of IPv6. There are some differences + in how IPv6 works and is provisioned; these differences have + implications for the network architecture. A typical IPv4 end-user + network consists of a "plug and play" router with NAT functionality + and a single link behind it, connected to the service provider + network. + + A typical IPv4 NAT deployment by default blocks all incoming + connections. Opening of ports is typically allowed using a Universal + Plug and Play Internet Gateway Device (UPnP IGD) [UPnP-IGD] or some + other firewall control protocol. + + Another consequence of using private address space in the end-user + network is that it provides stable addressing; that is, it never + changes even when you change service providers, and the addresses are + always there even when the WAN interface is down or the customer edge + router has not yet been provisioned. + + Many existing routers support dynamic routing (which learns routes + from other routers), and advanced end-users can build arbitrary, + complex networks using manual configuration of address prefixes + combined with a dynamic routing protocol. + +3.2. IPv6 End-User Network Architecture + + The end-user network architecture for IPv6 should provide equivalent + or better capabilities and functionality than the current IPv4 + architecture. + + + + + + + + + + + + + + + + + +Singh, et al. Informational [Page 5] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + The end-user network is a stub network. Figure 1 illustrates the + model topology for the end-user network. + + +-------+-------+ \ + | Service | \ + | Provider | | Service + | Router | | Provider + +-------+-------+ | Network + | / + | Customer / + | Internet Connection / + | + +------+--------+ \ + | IPv6 | \ + | Customer Edge | \ + | Router | / + +---+-------+-+-+ / + Network A | | Network B | End-User + ---+-------------+----+- --+--+-------------+--- | Network(s) + | | | | \ + +----+-----+ +-----+----+ +----+-----+ +-----+----+ \ + |IPv6 Host | |IPv6 Host | | IPv6 Host| |IPv6 Host | / + | | | | | | | | / + +----------+ +-----+----+ +----------+ +----------+ / + + Figure 1: An Example of a Typical End-User Network + + This architecture describes the: + + o Basic capabilities of an IPv6 CE router + + o Provisioning of the WAN interface connecting to the service + provider + + o Provisioning of the LAN interfaces + + For IPv6 multicast traffic, the IPv6 CE router may act as a Multicast + Listener Discovery (MLD) proxy [RFC4605] and may support a dynamic + multicast routing protocol. + + The IPv6 CE router may be manually configured in an arbitrary + topology with a dynamic routing protocol. Automatic provisioning and + configuration are described for a single IPv6 CE router only. + + + + + + + + +Singh, et al. Informational [Page 6] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + +3.2.1. Local Communication + + Link-local IPv6 addresses are used by hosts communicating on a single + link. Unique Local IPv6 Unicast Addresses (ULAs) [RFC4193] are used + by hosts communicating within the end-user network across multiple + links, but without requiring the application to use a globally + routable address. The IPv6 CE router defaults to acting as the + demarcation point between two networks by providing a ULA boundary, a + multicast zone boundary, and ingress and egress traffic filters. + + At the time of this writing, several host implementations do not + handle the case where they have an IPv6 address configured and no + IPv6 connectivity, either because the address itself has a limited + topological reachability (e.g., ULA) or because the IPv6 CE router is + not connected to the IPv6 network on its WAN interface. To support + host implementations that do not handle multihoming in a multi-prefix + environment [MULTIHOMING-WITHOUT-NAT], the IPv6 CE router should not, + as detailed in the requirements below, advertise itself as a default + router on the LAN interface(s) when it does not have IPv6 + connectivity on the WAN interface or when it is not provisioned with + IPv6 addresses. For local IPv6 communication, the mechanisms + specified in [RFC4191] are used. + + ULA addressing is useful where the IPv6 CE router has multiple LAN + interfaces with hosts that need to communicate with each other. If + the IPv6 CE router has only a single LAN interface (IPv6 link), then + link-local addressing can be used instead. + + Coexistence with IPv4 requires any IPv6 CE router(s) on the LAN to + conform to these recommendations, especially requirements ULA-5 and + L-4 below. + +4. Requirements + +4.1. General Requirements + + The IPv6 CE router is responsible for implementing IPv6 routing; that + is, the IPv6 CE router must look up the IPv6 destination address in + its routing table to decide to which interface it should send the + packet. + + In this role, the IPv6 CE router is responsible for ensuring that + traffic using its ULA addressing does not go out the WAN interface + and does not originate from the WAN interface. + + + + + + + +Singh, et al. Informational [Page 7] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + G-1: An IPv6 CE router is an IPv6 node according to the IPv6 Node + Requirements specification [RFC6434]. + + G-2: The IPv6 CE router MUST implement ICMPv6 according to + [RFC4443]. In particular, point-to-point links MUST be handled + as described in Section 3.1 of [RFC4443]. + + G-3: The IPv6 CE router MUST NOT forward any IPv6 traffic between + its LAN interface(s) and its WAN interface until the router has + successfully completed the IPv6 address and the delegated + prefix acquisition process. + + G-4: By default, an IPv6 CE router that has no default router(s) on + its WAN interface MUST NOT advertise itself as an IPv6 default + router on its LAN interfaces. That is, the "Router Lifetime" + field is set to zero in all Router Advertisement messages it + originates [RFC4861]. + + G-5: By default, if the IPv6 CE router is an advertising router and + loses its IPv6 default router(s) and/or detects loss of + connectivity on the WAN interface, it MUST explicitly + invalidate itself as an IPv6 default router on each of its + advertising interfaces by immediately transmitting one or more + Router Advertisement messages with the "Router Lifetime" field + set to zero [RFC4861]. + +4.2. WAN-Side Configuration + + The IPv6 CE router will need to support connectivity to one or more + access network architectures. This document describes an IPv6 CE + router that is not specific to any particular architecture or service + provider and that supports all commonly used architectures. + + IPv6 Neighbor Discovery and DHCPv6 protocols operate over any type of + IPv6-supported link layer, and there is no need for a link-layer- + specific configuration protocol for IPv6 network-layer configuration + options as in, e.g., PPP IP Control Protocol (IPCP) for IPv4. This + section makes the assumption that the same mechanism will work for + any link layer, be it Ethernet, the Data Over Cable Service Interface + Specification (DOCSIS), PPP, or others. + + + + + + + + + + + +Singh, et al. Informational [Page 8] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + WAN-side requirements: + + W-1: When the router is attached to the WAN interface link, it MUST + act as an IPv6 host for the purposes of stateless [RFC4862] or + stateful [RFC3315] interface address assignment. + + W-2: The IPv6 CE router MUST generate a link-local address and + finish Duplicate Address Detection according to [RFC4862] prior + to sending any Router Solicitations on the interface. The + source address used in the subsequent Router Solicitation MUST + be the link-local address on the WAN interface. + + W-3: Absent other routing information, the IPv6 CE router MUST use + Router Discovery as specified in [RFC4861] to discover a + default router(s) and install a default route(s) in its routing + table with the discovered router's address as the next hop. + + W-4: The router MUST act as a requesting router for the purposes of + DHCPv6 prefix delegation ([RFC3633]). + + W-5: The IPv6 CE router MUST use a persistent DHCP Unique Identifier + (DUID) for DHCPv6 messages. The DUID MUST NOT change between + network-interface resets or IPv6 CE router reboots. + + W-6: The WAN interface of the CE router SHOULD support a Port + Control Protocol (PCP) client as specified in [RFC6887] for use + by applications on the CE router. The PCP client SHOULD follow + the procedure specified in Section 8.1 of [RFC6887] to discover + its PCP server. This document takes no position on whether + such functionality is enabled by default or mechanisms by which + users would configure the functionality. Handling PCP requests + from PCP clients in the LAN side of the CE router is out of + scope. + + Link-layer requirements: + + WLL-1: If the WAN interface supports Ethernet encapsulation, then + the IPv6 CE router MUST support IPv6 over Ethernet [RFC2464]. + + WLL-2: If the WAN interface supports PPP encapsulation, the IPv6 CE + router MUST support IPv6 over PPP [RFC5072]. + + WLL-3: If the WAN interface supports PPP encapsulation, in a dual- + stack environment with IPCP and IPV6CP running over one PPP + logical channel, the Network Control Protocols (NCPs) MUST be + treated as independent of each other and start and terminate + independently. + + + + +Singh, et al. Informational [Page 9] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + Address assignment requirements: + + WAA-1: The IPv6 CE router MUST support Stateless Address + Autoconfiguration (SLAAC) [RFC4862]. + + WAA-2: The IPv6 CE router MUST follow the recommendations in + Section 4 of [RFC5942], and in particular the handling of + the L flag in the Router Advertisement Prefix Information + option. + + WAA-3: The IPv6 CE router MUST support DHCPv6 [RFC3315] client + behavior. + + WAA-4: The IPv6 CE router MUST be able to support the following + DHCPv6 options: Identity Association for Non-temporary + Address (IA_NA), Reconfigure Accept [RFC3315], and + DNS_SERVERS [RFC3646]. The IPv6 CE router SHOULD be able to + support the DNS Search List (DNSSL) option as specified in + [RFC3646]. + + WAA-5: The IPv6 CE router SHOULD implement the Network Time + Protocol (NTP) as specified in [RFC5905] to provide a time + reference common to the service provider for other + protocols, such as DHCPv6, to use. If the CE router + implements NTP, it requests the NTP Server DHCPv6 option + [RFC5908] and uses the received list of servers as primary + time reference, unless explicitly configured otherwise. LAN + side support of NTP is out of scope for this document. + + WAA-6: If the IPv6 CE router receives a Router Advertisement + message (described in [RFC4861]) with the M flag set to 1, + the IPv6 CE router MUST do DHCPv6 address assignment + (request an IA_NA option). + + WAA-7: If the IPv6 CE router does not acquire a global IPv6 + address(es) from either SLAAC or DHCPv6, then it MUST create + a global IPv6 address(es) from its delegated prefix(es) and + configure those on one of its internal virtual network + interfaces, unless configured to require a global IPv6 + address on the WAN interface. + + WAA-8: The CE router MUST support the SOL_MAX_RT option [RFC7083] + and request the SOL_MAX_RT option in an Option Request + Option (ORO). + + + + + + + +Singh, et al. Informational [Page 10] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + WAA-9: As a router, the IPv6 CE router MUST follow the weak host + (Weak End System) model [RFC1122]. When originating packets + from an interface, it will use a source address from another + one of its interfaces if the outgoing interface does not + have an address of suitable scope. + + WAA-10: The IPv6 CE router SHOULD implement the Information Refresh + Time option and associated client behavior as specified in + [RFC4242]. + + Prefix delegation requirements: + + WPD-1: The IPv6 CE router MUST support DHCPv6 prefix delegation + requesting router behavior as specified in [RFC3633] + (Identity Association for Prefix Delegation (IA_PD) option). + + WPD-2: The IPv6 CE router MAY indicate as a hint to the delegating + router the size of the prefix it requires. If so, it MUST + ask for a prefix large enough to assign one /64 for each of + its interfaces, rounded up to the nearest nibble, and SHOULD + be configurable to ask for more. + + WPD-3: The IPv6 CE router MUST be prepared to accept a delegated + prefix size different from what is given in the hint. If the + delegated prefix is too small to address all of its + interfaces, the IPv6 CE router SHOULD log a system management + error. [RFC6177] covers the recommendations for service + providers for prefix allocation sizes. + + WPD-4: By default, the IPv6 CE router MUST initiate DHCPv6 prefix + delegation when either the M or O flags are set to 1 in a + received Router Advertisement (RA) message. Behavior of the + CE router to use DHCPv6 prefix delegation when the CE router + has not received any RA or received an RA with the M and the + O bits set to zero is out of scope for this document. + + WPD-5: Any packet received by the CE router with a destination + address in the prefix(es) delegated to the CE router but not + in the set of prefixes assigned by the CE router to the LAN + must be dropped. In other words, the next hop for the + prefix(es) delegated to the CE router should be the null + destination. This is necessary to prevent forwarding loops + when some addresses covered by the aggregate are not + reachable [RFC4632]. + + + + + + + +Singh, et al. Informational [Page 11] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + (a) The IPv6 CE router SHOULD send an ICMPv6 Destination + Unreachable message in accordance with Section 3.1 of + [RFC4443] back to the source of the packet, if the packet is + to be dropped due to this rule. + + WPD-6: If the IPv6 CE router requests both an IA_NA and an IA_PD + option in DHCPv6, it MUST accept an IA_PD option in DHCPv6 + Advertise/Reply messages, even if the message does not + contain any addresses, unless configured to only obtain its + WAN IPv6 address via DHCPv6; see [DHCPv6-STATEFUL-ISSUES]. + + WPD-7: By default, an IPv6 CE router MUST NOT initiate any dynamic + routing protocol on its WAN interface. + + WPD-8: The IPv6 CE router SHOULD support the [RFC6603] Prefix + Exclude option. + +4.3. LAN-Side Configuration + + The IPv6 CE router distributes configuration information obtained + during WAN interface provisioning to IPv6 hosts and assists IPv6 + hosts in obtaining IPv6 addresses. It also supports connectivity of + these devices in the absence of any working WAN interface. + + An IPv6 CE router is expected to support an IPv6 end-user network and + IPv6 hosts that exhibit the following characteristics: + + 1. Link-local addresses may be insufficient for allowing IPv6 + applications to communicate with each other in the end-user + network. The IPv6 CE router will need to enable this + communication by providing globally scoped unicast addresses or + ULAs [RFC4193], whether or not WAN connectivity exists. + + 2. IPv6 hosts should be capable of using SLAAC and may be capable of + using DHCPv6 for acquiring their addresses. + + 3. IPv6 hosts may use DHCPv6 for other configuration information, + such as the DNS_SERVERS option for acquiring DNS information. + + Unless otherwise specified, the following requirements apply to the + IPv6 CE router's LAN interfaces only. + + ULA requirements: + + ULA-1: The IPv6 CE router SHOULD be capable of generating a ULA + prefix [RFC4193]. + + + + + +Singh, et al. Informational [Page 12] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + ULA-2: An IPv6 CE router with a ULA prefix MUST maintain this prefix + consistently across reboots. + + ULA-3: The value of the ULA prefix SHOULD be configurable. + + ULA-4: By default, the IPv6 CE router MUST act as a site border + router according to Section 4.3 of [RFC4193] and filter + packets with local IPv6 source or destination addresses + accordingly. + + ULA-5: An IPv6 CE router MUST NOT advertise itself as a default + router with a Router Lifetime greater than zero whenever all + of its configured and delegated prefixes are ULA prefixes. + + LAN requirements: + + L-1: The IPv6 CE router MUST support router behavior according to + Neighbor Discovery for IPv6 [RFC4861]. + + L-2: The IPv6 CE router MUST assign a separate /64 from its + delegated prefix(es) (and ULA prefix if configured to provide + ULA addressing) for each of its LAN interfaces. + + L-3: An IPv6 CE router MUST advertise itself as a router for the + delegated prefix(es) (and ULA prefix if configured to provide + ULA addressing) using the "Route Information Option" specified + in Section 2.3 of [RFC4191]. This advertisement is + independent of having or not having IPv6 connectivity on the + WAN interface. + + L-4: An IPv6 CE router MUST NOT advertise itself as a default + router with a Router Lifetime [RFC4861] greater than zero if + it has no prefixes configured or delegated to it. + + L-5: The IPv6 CE router MUST make each LAN interface an advertising + interface according to [RFC4861]. + + L-6: In Router Advertisement messages ([RFC4861]), the Prefix + Information option's A and L flags MUST be set to 1 by + default. + + L-7: The A and L flags' ([RFC4861]) settings SHOULD be user + configurable. + + L-8: The IPv6 CE router MUST support a DHCPv6 server capable of + IPv6 address assignment according to [RFC3315] OR a stateless + DHCPv6 server according to [RFC3736] on its LAN interfaces. + + + + +Singh, et al. Informational [Page 13] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + L-9: Unless the IPv6 CE router is configured to support the DHCPv6 + IA_NA option, it SHOULD set the M flag to zero and the O flag + to 1 in its Router Advertisement messages [RFC4861]. + + L-10: The IPv6 CE router MUST support providing DNS information in + the DHCPv6 DNS_SERVERS and DOMAIN_LIST options [RFC3646]. + + L-11: The IPv6 CE router MUST support providing DNS information in + the Router Advertisement Recursive DNS Server (RDNSS) and DNS + Search List options. Both options are specified in [RFC6106]. + + L-12: The IPv6 CE router SHOULD make available a subset of DHCPv6 + options (as listed in Section 5.3 of [RFC3736]) received from + the DHCPv6 client on its WAN interface to its LAN-side DHCPv6 + server. + + L-13: If the delegated prefix changes, i.e., the current prefix is + replaced with a new prefix without any overlapping time + period, then the IPv6 CE router MUST immediately advertise the + old prefix with a Preferred Lifetime of zero and a Valid + Lifetime of either a) zero or b) the lower of the current + Valid Lifetime and two hours (which must be decremented in + real time) in a Router Advertisement message as described in + Section 5.5.3, (e) of [RFC4862]. + + L-14: The IPv6 CE router MUST send an ICMPv6 Destination Unreachable + message, code 5 (Source address failed ingress/egress policy) + for packets forwarded to it that use an address from a prefix + that has been invalidated. + +4.4. Transition Technologies Support + +4.4.1. 6rd + + 6rd [RFC5969] specifies an automatic tunneling mechanism tailored to + advance deployment of IPv6 to end users via a service provider's IPv4 + network infrastructure. Key aspects include automatic IPv6 prefix + delegation to sites, stateless operation, simple provisioning, and + service that is equivalent to native IPv6 at the sites that are + served by the mechanism. It is expected that such traffic is + forwarded over the CE router's native IPv4 WAN interface and not + encapsulated in another tunnel. + + The CE router SHOULD support 6rd functionality. If 6rd is supported, + it MUST be implemented according to [RFC5969]. The following CE + Requirements also apply: + + + + + +Singh, et al. Informational [Page 14] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + 6rd requirements: + + 6RD-1: The IPv6 CE router MUST support 6rd configuration via the 6rd + DHCPv4 Option 212. If the CE router has obtained an IPv4 + network address through some other means such as PPP, it + SHOULD use the DHCPINFORM request message [RFC2131] to + request the 6rd DHCPv4 Option. The IPv6 CE router MAY use + other mechanisms to configure 6rd parameters. Such + mechanisms are outside the scope of this document. + + 6RD-2: If the IPv6 CE router is capable of automated configuration + of IPv4 through IPCP (i.e., over a PPP connection), it MUST + support user-entered configuration of 6rd. + + 6RD-3: If the CE router supports configuration mechanisms other than + the 6rd DHCPv4 Option 212 (user-entered, TR-069 [TR-069], + etc.), the CE router MUST support 6rd in "hub and spoke" + mode. 6rd in "hub and spoke" requires all IPv6 traffic to go + to the 6rd Border Relay. In effect, this requirement removes + the "direct connect to 6rd" route defined in Section 7.1.1 of + [RFC5969]. + + 6RD-4: A CE router MUST allow 6rd and native IPv6 WAN interfaces to + be active alone as well as simultaneously in order to support + coexistence of the two technologies during an incremental + migration period such as a migration from 6rd to native IPv6. + + 6RD-5: Each packet sent on a 6rd or native WAN interface MUST be + directed such that its source IP address is derived from the + delegated prefix associated with the particular interface + from which the packet is being sent (Section 4.3 of + [RFC3704]). + + 6RD-6: The CE router MUST allow different as well as identical + delegated prefixes to be configured via each (6rd or native) + WAN interface. + + 6RD-7: In the event that forwarding rules produce a tie between 6rd + and native IPv6, by default, the IPv6 CE router MUST prefer + native IPv6. + +4.4.2. Dual-Stack Lite (DS-Lite) + + Dual-Stack Lite [RFC6333] enables both continued support for IPv4 + services and incentives for the deployment of IPv6. It also + de-couples IPv6 deployment in the service provider network from the + rest of the Internet, making incremental deployment easier. Dual- + Stack Lite enables a broadband service provider to share IPv4 + + + +Singh, et al. Informational [Page 15] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + addresses among customers by combining two well-known technologies: + IP in IP (IPv4-in-IPv6) and Network Address Translation (NAT). It is + expected that DS-Lite traffic is forwarded over the CE router's + native IPv6 WAN interface, and not encapsulated in another tunnel. + + The IPv6 CE router SHOULD implement DS-Lite functionality. If + DS-Lite is supported, it MUST be implemented according to [RFC6333]. + This document takes no position on simultaneous operation of Dual- + Stack Lite and native IPv4. The following CE router requirements + also apply: + + WAN requirements: + + DLW-1: The CE router MUST support configuration of DS-Lite via the + DS-Lite DHCPv6 option [RFC6334]. The IPv6 CE router MAY use + other mechanisms to configure DS-Lite parameters. Such + mechanisms are outside the scope of this document. + + DLW-2: The IPv6 CE router MUST NOT perform IPv4 Network Address + Translation (NAT) on IPv4 traffic encapsulated using DS-Lite. + + DLW-3: If the IPv6 CE router is configured with an IPv4 address on + its WAN interface, then the IPv6 CE router SHOULD disable the + DS-Lite Basic Bridging BroadBand (B4) element. + +4.5. Security Considerations + + It is considered a best practice to filter obviously malicious + traffic (e.g., spoofed packets, "Martian" addresses, etc.). Thus, + the IPv6 CE router ought to support basic stateless egress and + ingress filters. The CE router is also expected to offer mechanisms + to filter traffic entering the customer network; however, the method + by which vendors implement configurable packet filtering is beyond + the scope of this document. + + Security requirements: + + S-1: The IPv6 CE router SHOULD support [RFC6092]. In particular, + the IPv6 CE router SHOULD support functionality sufficient for + implementing the set of recommendations in [RFC6092], + Section 4. This document takes no position on whether such + functionality is enabled by default or mechanisms by which + users would configure it. + + + + + + + + +Singh, et al. Informational [Page 16] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + S-2: The IPv6 CE router SHOULD support ingress filtering in + accordance with BCP 38 [RFC2827]. Note that this requirement + was downgraded from a MUST from RFC 6204 due to the difficulty + of implementation in the CE router and the feature's redundancy + with upstream router ingress filtering. + + S-3: If the IPv6 CE router firewall is configured to filter incoming + tunneled data, the firewall SHOULD provide the capability to + filter decapsulated packets from a tunnel. + +5. Acknowledgements + + Thanks to the following people (in alphabetical order) for their + guidance and feedback: + + Mikael Abrahamsson, Tore Anderson, Merete Asak, Rajiv Asati, Scott + Beuker, Mohamed Boucadair, Rex Bullinger, Brian Carpenter, Tassos + Chatzithomaoglou, Lorenzo Colitti, Remi Denis-Courmont, Gert Doering, + Alain Durand, Katsunori Fukuoka, Brian Haberman, Tony Hain, Thomas + Herbst, Ray Hunter, Joel Jaeggli, Kevin Johns, Erik Kline, Stephen + Kramer, Victor Kuarsingh, Francois-Xavier Le Bail, Arifumi Matsumoto, + David Miles, Shin Miyakawa, Jean-Francois Mule, Michael Newbery, + Carlos Pignataro, John Pomeroy, Antonio Querubin, Daniel Roesen, + Hiroki Sato, Teemu Savolainen, Matt Schmitt, David Thaler, Mark + Townsley, Sean Turner, Bernie Volz, Dan Wing, Timothy Winters, James + Woodyatt, Carl Wuyts, and Cor Zwart. + + This document is based in part on CableLabs' eRouter specification. + The authors wish to acknowledge the additional contributors from the + eRouter team: + + Ben Bekele, Amol Bhagwat, Ralph Brown, Eduardo Cardona, Margo Dolas, + Toerless Eckert, Doc Evans, Roger Fish, Michelle Kuska, Diego + Mazzola, John McQueen, Harsh Parandekar, Michael Patrick, Saifur + Rahman, Lakshmi Raman, Ryan Ross, Ron da Silva, Madhu Sudan, Dan + Torbet, and Greg White. + +6. Contributors + + The following people have participated as co-authors or provided + substantial contributions to this document: Ralph Droms, Kirk + Erichsen, Fred Baker, Jason Weil, Lee Howard, Jean-Francois Tremblay, + Yiu Lee, John Jason Brzozowski, and Heather Kirksey. Thanks to Ole + Troan for editorship in the original RFC 6204 document. + + + + + + + +Singh, et al. Informational [Page 17] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + +7. References + +7.1. Normative References + + [RFC1122] Braden, R., "Requirements for Internet Hosts - + Communication Layers", STD 3, RFC 1122, October 1989. + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC + 2131, March 1997. + + [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet + Networks", RFC 2464, December 1998. + + [RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering: + Defeating Denial of Service Attacks which employ IP Source + Address Spoofing", BCP 38, RFC 2827, May 2000. + + [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., + and M. Carney, "Dynamic Host Configuration Protocol for + IPv6 (DHCPv6)", RFC 3315, July 2003. + + [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic + Host Configuration Protocol (DHCP) version 6", RFC 3633, + December 2003. + + [RFC3646] Droms, R., "DNS Configuration options for Dynamic Host + Configuration Protocol for IPv6 (DHCPv6)", RFC 3646, + December 2003. + + [RFC3704] Baker, F. and P. Savola, "Ingress Filtering for Multihomed + Networks", BCP 84, RFC 3704, March 2004. + + [RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol + (DHCP) Service for IPv6", RFC 3736, April 2004. + + [RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and + More-Specific Routes", RFC 4191, November 2005. + + [RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast + Addresses", RFC 4193, October 2005. + + [RFC4242] Venaas, S., Chown, T., and B. Volz, "Information Refresh + Time Option for Dynamic Host Configuration Protocol for + IPv6 (DHCPv6)", RFC 4242, November 2005. + + + + +Singh, et al. Informational [Page 18] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + [RFC4443] Conta, A., Deering, S., and M. Gupta, "Internet Control + Message Protocol (ICMPv6) for the Internet Protocol + Version 6 (IPv6) Specification", RFC 4443, March 2006. + + [RFC4605] Fenner, B., He, H., Haberman, B., and H. Sandick, + "Internet Group Management Protocol (IGMP) / Multicast + Listener Discovery (MLD)-Based Multicast Forwarding + ("IGMP/MLD Proxying")", RFC 4605, August 2006. + + [RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing + (CIDR): The Internet Address Assignment and Aggregation + Plan", BCP 122, RFC 4632, August 2006. + + [RFC4779] Asadullah, S., Ahmed, A., Popoviciu, C., Savola, P., and + J. Palet, "ISP IPv6 Deployment Scenarios in Broadband + Access Networks", RFC 4779, January 2007. + + [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, + "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, + September 2007. + + [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless + Address Autoconfiguration", RFC 4862, September 2007. + + [RFC5072] Varada, S., Haskins, D., and E. Allen, "IP Version 6 over + PPP", RFC 5072, September 2007. + + [RFC5905] Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network + Time Protocol Version 4: Protocol and Algorithms + Specification", RFC 5905, June 2010. + + [RFC5908] Gayraud, R. and B. Lourdelet, "Network Time Protocol (NTP) + Server Option for DHCPv6", RFC 5908, June 2010. + + [RFC5942] Singh, H., Beebee, W., and E. Nordmark, "IPv6 Subnet + Model: The Relationship between Links and Subnet + Prefixes", RFC 5942, July 2010. + + [RFC5969] Townsley, W. and O. Troan, "IPv6 Rapid Deployment on IPv4 + Infrastructures (6rd) -- Protocol Specification", RFC + 5969, August 2010. + + [RFC6092] Woodyatt, J., "Recommended Simple Security Capabilities in + Customer Premises Equipment (CPE) for Providing + Residential IPv6 Internet Service", RFC 6092, January + 2011. + + + + + +Singh, et al. Informational [Page 19] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + [RFC6106] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli, + "IPv6 Router Advertisement Options for DNS Configuration", + RFC 6106, November 2010. + + [RFC6177] Narten, T., Huston, G., and L. Roberts, "IPv6 Address + Assignment to End Sites", BCP 157, RFC 6177, March 2011. + + [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- + Stack Lite Broadband Deployments Following IPv4 + Exhaustion", RFC 6333, August 2011. + + [RFC6334] Hankins, D. and T. Mrugalski, "Dynamic Host Configuration + Protocol for IPv6 (DHCPv6) Option for Dual-Stack Lite", + RFC 6334, August 2011. + + [RFC6434] Jankiewicz, E., Loughney, J., and T. Narten, "IPv6 Node + Requirements", RFC 6434, December 2011. + + [RFC6603] Korhonen, J., Savolainen, T., Krishnan, S., and O. Troan, + "Prefix Exclude Option for DHCPv6-based Prefix + Delegation", RFC 6603, May 2012. + + [RFC6887] Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P. + Selkirk, "Port Control Protocol (PCP)", RFC 6887, April + 2013. + + [RFC7083] Droms, R., "Modification to Default Values of SOL_MAX_RT + and INF_MAX_RT", RFC 7083, November 2013. + +7.2. Informative References + + [DHCPv6-STATEFUL-ISSUES] + Troan, O. and B. Volz, "Issues with multiple stateful + DHCPv6 options", Work in Progress, May 2013. + + [MULTIHOMING-WITHOUT-NAT] + Troan, O., Ed., Miles, D., Matsushima, S., Okimoto, T., + and D. Wing, "IPv6 Multihoming without Network Address + Translation", Work in Progress, December 2010. + + [RFC6144] Baker, F., Li, X., Bao, C., and K. Yin, "Framework for + IPv4/IPv6 Translation", RFC 6144, April 2011. + + [TR-069] Broadband Forum, "CPE WAN Management Protocol", TR-069 + Amendment 4, July 2011, + . + + + + + +Singh, et al. Informational [Page 20] + +RFC 7084 IPv6 CE Router Requirements November 2013 + + + [UPnP-IGD] UPnP Forum, , "InternetGatewayDevice:2 Device Template + Version 1.01", December 2010, + . + +Authors' Addresses + + Hemant Singh + Cisco Systems, Inc. + 1414 Massachusetts Ave. + Boxborough, MA 01719 + USA + + Phone: +1 978 936 1622 + EMail: shemant@cisco.com + URI: http://www.cisco.com/ + + + Wes Beebee + Cisco Systems, Inc. + 1414 Massachusetts Ave. + Boxborough, MA 01719 + USA + + Phone: +1 978 936 2030 + EMail: wbeebee@cisco.com + URI: http://www.cisco.com/ + + + Chris Donley + CableLabs + 858 Coal Creek Circle + Louisville, CO 80027 + USA + + EMail: c.donley@cablelabs.com + + + Barbara Stark + AT&T + 1057 Lenox Park Blvd. NE + Atlanta, GA 30319 + USA + + EMail: barbara.stark@att.com + + + + + + + +Singh, et al. Informational [Page 21] + -- cgit v1.2.3