draft-ietf-v6ops-ipv6-cpe-router-03.txt   draft-ietf-v6ops-ipv6-cpe-router-04.txt 
Internet Engineering Task Force H. Singh Internet Engineering Task Force H. Singh
Internet-Draft W. Beebee Internet-Draft W. Beebee
Intended status: Informational Cisco Systems, Inc. Intended status: Informational Cisco Systems, Inc.
Expires: June 21, 2010 C. Donley Expires: July 28, 2010 C. Donley
CableLabs CableLabs
B. Stark B. Stark
AT&T AT&T
O. Troan, Ed. O. Troan, Ed.
Cisco Systems, Inc. Cisco Systems, Inc.
December 18, 2009 January 24, 2010
Basic Requirements for IPv6 Customer Edge Routers Basic Requirements for IPv6 Customer Edge Routers
draft-ietf-v6ops-ipv6-cpe-router-03 draft-ietf-v6ops-ipv6-cpe-router-04
Abstract Abstract
This document specifies requirements for an IPv6 Customer Edge (CE) This document specifies requirements for an IPv6 Customer Edge (CE)
router. Specifically, the current version of this document focuses router. Specifically, the current version of this document focuses
on the provisioning of an IPv6 CE router and the provisioning of IPv6 on the basic provisioning of an IPv6 CE router and the provisioning
hosts attached to it. of IPv6 hosts attached to it.
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
skipping to change at page 1, line 45 skipping to change at page 1, line 45
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on June 21, 2010. This Internet-Draft will expire on July 28, 2010.
Copyright Notice Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
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publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
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described in the BSD License. described in the BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Current IPv4 end-user network architecture . . . . . . . . 4 3.1. Current IPv4 End-user Network Architecture . . . . . . . . 4
3.2. IPv6 end-user network architecture . . . . . . . . . . . . 5 3.2. IPv6 End-user Network Architecture . . . . . . . . . . . . 5
4. Use Cases and Requirements . . . . . . . . . . . . . . . . . . 6 4. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. WAN side configuration . . . . . . . . . . . . . . . . . . 6 4.1. General Requirements . . . . . . . . . . . . . . . . . . . 6
4.2. LAN side configuration . . . . . . . . . . . . . . . . . . 8 4.2. WAN Side Configuration . . . . . . . . . . . . . . . . . . 6
4.3. General requirements . . . . . . . . . . . . . . . . . . . 9 4.3. LAN Side Configuration . . . . . . . . . . . . . . . . . . 9
4.4. Security Considerations . . . . . . . . . . . . . . . . . 10 4.4. Security Considerations . . . . . . . . . . . . . . . . . 11
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11
6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 11 6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
8. Normative References . . . . . . . . . . . . . . . . . . . . . 11 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Appendix A. Changes in revision 3 . . . . . . . . . . . . . . . . 13 8.1. Normative References . . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13 8.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
This document defines IPv6 features for a residential or small office This document defines basic IPv6 features for a residential or small
router referred to as an IPv6 CE router. Typically these routers office router referred to as an IPv6 CE router. Typically these
also support IPv4. routers 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 [I-D.ietf-behave-v6v4-framework].
Support for such mixed environments is not in scope of this document.
This document specifies how an IPv6 CE router automatically This document specifies how an IPv6 CE router automatically
provisions its WAN interface, acquires an address block for provisions its WAN interface, acquires address space for provisioning
provisioning of its LAN interfaces and fetches other configuration of its LAN interfaces and fetches other configuration information
information from the service provider network. Automatic from the service provider network. Automatic provisioning of more
provisioning of more complex topology than a single router with complex topology than a single router with multiple LAN interfaces is
multiple LAN interfaces is out of scope for this document. out of scope for this document.
See [RFC4779] for a discussion of options available for deploying See [RFC4779] for a discussion of options available for deploying
IPv6 in service provider access networks. IPv6 in Service Provider access networks.
1.1. Requirements Language 1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
2. Terminology 2. Terminology
End-user Network one or more links attached to the IPv6 CE End-user Network one or more links attached to the IPv6 CE
router that connect IPv6 hosts. router that connect IPv6 hosts.
IPv6 Customer Edge router a node intended for home or small office IPv6 Customer Edge router a node intended for home or small office
use which forwards IPv6 packets not explicitly use which forwards IPv6 packets not
addressed to itself. The IPv6 CE router explicitly addressed to itself. The IPv6
connects the end-user network to a service CE router connects the end-user network to
provider network. a service provider network.
IPv6 host any device implementing an IPv6 stack receiving IPv6 host any device implementing an IPv6 stack
IPv6 Internet connectivity through the IPv6 CE receiving IPv6 connectivity through the
router IPv6 CE router
LAN interface an IPv6 CE router's attachment to a link in the LAN interface an IPv6 CE router's attachment to a link in
end-user network. Examples are Ethernets the end-user network. Examples are
(simple or bridged), 802.11 wireless or other Ethernets (simple or bridged), 802.11
LAN technologies. An IPv6 CE router may have wireless or other LAN technologies. An
one or more network layer LAN Interfaces. IPv6 CE router may have one or more network
layer LAN Interfaces.
Service Provider a company that offers its customers access to Service Provider an entity that provides access to the
the Internet. In this document, a Service Internet. In this document, a Service
Provider specifically offers Internet access Provider specifically offers Internet
using IPv6, and may also offer IPv4 Internet access using IPv6, and may also offer IPv4
access. The Service Provider can provide such Internet access. The Service Provider can
access over a variety of different transport provide such access over a variety of
methods such as DSL, cable, wireless, and different transport methods such as DSL,
others. cable, wireless, and others.
WAN interface an IPv6 CE router's attachment to a link used WAN interface an IPv6 CE router's attachment to a link
to provide connectivity to the Service Provider used to provide connectivity to the Service
network; example link technologies include Provider network; example link technologies
Ethernets (simple or bridged), PPP links, X.25, include Ethernets (simple or bridged), PPP
Frame Relay, or ATM networks as well as links, Frame Relay, or ATM networks as well
Internet-layer (or higher-layer) "tunnels", as Internet-layer (or higher-layer)
such as tunnels over IPv4 or IPv6 itself. "tunnels", such as tunnels over IPv4 or
IPv6 itself.
3. Architecture 3. Architecture
3.1. Current IPv4 end-user network architecture 3.1. Current IPv4 End-user Network Architecture
An end-user network will likely have to support both IPv4 and IPv6. An end-user network will likely support both IPv4 and IPv6. It is
It is not expected that an end-user will change their existing not expected that an end-user will change their existing network
network topology with the introduction of IPv6. There are some topology with the introduction of IPv6. There are some differences
differences in how IPv6 works and is provisioned which has in how IPv6 works and is provisioned which has implications for the
implications for the network architecture. A typical IPv4 end-user network architecture. A typical IPv4 end-user network consist of a
network consist of a "plug and play" NAT box connected to the ISP. "plug and play" router with NAT functionality and a single link
The assumption is a single NAT device with a single link behind it. behind it, connected to the Service Provider network.
The NAT provides stable addressing allowing for manually configured
addresses on the nodes in the end-user network.
A typical IPv4 NAT deployment by default blocks all incoming A typical IPv4 NAT deployment by default blocks all incoming
connections. Opening of ports is typically allowed using UPnP or connections. Opening of ports is typically allowed using UPnP IGD
some other firewall control protocol. [UPnP-IGD] or some other firewall control protocol.
Another consequence of using private address space in the end-user Another consequence of using private address space in the end-user
network is that it provides stable addressing, i.e. it never changes network is that it provides stable addressing, i.e. it never changes
even when you change ISPs, and the addresses are always there even even when you change Service Providers, and the addresses are always
when the WAN interface is down or the customer edge router has not there even when the WAN interface is down or the customer edge router
yet been provisioned. has not yet been provisioned.
Rewriting addresses on the edge of the network also allows for some Rewriting addresses on the edge of the network also allows for some
rudimentary multi-homing; even though using NATs for multi-homing rudimentary multi-homing; even though using NATs for multi-homing
does not preserve connections during fail-overs [RFC4864]. does not preserve connections during a fail-over event [RFC4864].
Many existing routers support dynamic routing, and advanced end users Many existing routers support dynamic routing, and advanced end users
can build arbitrary, complex networks using manual configuration of can build arbitrary, complex networks using manual configuration of
address prefixes combined with a dynamic routing protocol. address prefixes combined with a dynamic routing protocol.
3.2. IPv6 end-user network architecture 3.2. IPv6 End-user Network Architecture
The end-user network architecture for IPv6 should provide equivalent The end-user network architecture for IPv6 should provide equivalent
or better capabilities and functionality than the equivalent IPv4 or better capabilities and functionality than the current IPv4
architecture. architecture.
The end-user network is a stub network. Figure 1 illustrates the The end-user network is a stub network. Figure 1 illustrates the
model topology for the end-user network. model topology for the end-user network.
An example of a typical end-user network. An example of a typical end-user network.
+-------+-------+ \ +-------+-------+ \
| Service | \ | Service | \
| Provider | | ISP | Provider | | Service
| Router | | network | Router | | Provider
+-------+-------+ | +-------+-------+ | network
| / | /
| Customer / | Customer /
| Internet connection / | Internet connection /
| |
+------+--------+ \ +------+--------+ \
| IPv6 | \ | IPv6 | \
| Customer Edge | \ | Customer Edge | \
| Router | / | Router | /
+---+-------+-+-+ / +---+-------+-+-+ /
Network A | | Network B | Customer Network A | | Network B | End-User
---+-------------+----+- --+--+-------------+--- |network(s) ---+-------------+----+- --+--+-------------+--- |network(s)
| | | | \ | | | | \
+----+-----+ +-----+----+ +----+-----+ +-----+----+ \ +----+-----+ +-----+----+ +----+-----+ +-----+----+ \
|IPv6 Host | |IPv6 Host | | IPv6 Host| |IPv6 Host | / |IPv6 Host | |IPv6 Host | | IPv6 Host| |IPv6 Host | /
| | | | | | | | / | | | | | | | | /
+----------+ +-----+----+ +----------+ +----------+/ +----------+ +-----+----+ +----------+ +----------+/
Figure 1 Figure 1
This architecture describes the: This architecture describes the:
o Basic capabilities of an IPv6 CE router o Basic capabilities of an IPv6 CE router
o Provisioning of the WAN interface connecting to the ISP o Provisioning of the WAN interface connecting to the Service
Provider
o Provisioning of the LAN interfaces o Provisioning of the LAN interfaces
Unique Local IPv6 Unicast Addresses (ULA) [RFC4193] are used by hosts
communicating within the End-user Network; this is functionally
similar to RFC1918 addresses used within an IPv4 End-user Network.
The IPv6 CE router defaults to acting as the demarcation point The IPv6 CE router defaults to acting as the demarcation point
between two networks by providing a ULA boundary, a multicast zone between two networks by providing a ULA boundary, a multicast zone
boundary and ingress and egress traffic filters. boundary and ingress and egress traffic filters.
For IPv6 multicast traffic the IPv6 CE router may act as an MLD proxy For IPv6 multicast traffic the IPv6 CE router may act as an MLD proxy
[RFC4605] and may support a dynamic multicast routing protocol. [RFC4605] and may support a dynamic multicast routing protocol.
IPv6 CE router may be manually configured in an arbitrary topology The IPv6 CE router may be manually configured in an arbitrary
with a dynamic routing protocol. Automatic provisioning and topology with a dynamic routing protocol. Automatic provisioning and
configuration is described for a single IPv6 CE router only. configuration is described for a single IPv6 CE router only.
4. Use Cases and Requirements 4. Requirements
4.1. WAN side configuration 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.
G-1: An IPv6 CE router is an IPv6 node according to the IPv6 Node
Requirements [RFC4294] specification.
G-2: 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 acquisition process.
4.2. WAN Side Configuration
The IPv6 CE router will need to support connectivity to one or more The IPv6 CE router will need to support connectivity to one or more
access network architectures. This document describes an IPv6 CE access network architectures. This document describes an IPv6 CE
router that is not specific to any particular architecture or Service router that is not specific to any particular architecture or Service
Provider, and supports all commonly used architectures. Provider, and supports all commonly used architectures.
IPv6 Neighbor Discovery and DHCP protocols operate over any type of IPv6 Neighbor Discovery and DHCPv6 protocols operate over any type of
IPv6 supported link-layer and there is no need for a link-layer IPv6 supported link-layer and there is no need for a link-layer
specific configuration protocol for IPv6 network layer configuration specific configuration protocol for IPv6 network layer configuration
options as in PPP IPCP for IPv4. This section makes the assumption options as in e.g. PPP IPCP for IPv4. This section makes the
that the same mechanism will work for any link-layer, be it Ethernet, assumption that the same mechanism will work for any link-layer, be
DOCSIS, PPP/PPPoE or others. it Ethernet, DOCSIS, PPP or others.
When the router is attached to the WAN interface link it must act as WAN side requirements:
an IPv6 host for the purposes of stateless or stateful interface
address assignment ([RFC4862]/[RFC3315]). The router acts as a
requesting router for the purposes of DHCP prefix delegation
([RFC3633]).
DHCP address assignment (IA_NA) and DHCP prefix delegation (IA_PD) W-1: When the router is attached to the WAN interface link it MUST
should be done as a single DHCP session. act as an IPv6 host for the purposes of stateless or stateful
interface address assignment ([RFC4862]/[RFC3315]).
W-2: The router MUST act as a requesting router for the purposes of
DHCPv6 prefix delegation ([RFC3633]).
W-3: DHCPv6 address assignment (IA_NA) and DHCPv6 prefix delegation
(IA_PD) SHOULD be done as a single DHCPv6 session.
Link-layer requirements: Link-layer requirements:
WLL-1: The IPv6 CE router MUST support IPv6 over Ethernet [RFC2464]. WLL-1: If the WAN interface supports Ethernet encapsulation, then
the IPv6 CE router MUST support IPv6 over Ethernet [RFC2464].
WLL-2: The IPv6 CE router MUST support IPv6 over PPP [RFC5072] and WLL-2: If the WAN interface supports PPP encapsulation the IPv6 CE
PPPoE [RFC2516]. In a dual-stack environment with IPCP and router MUST support IPv6 over PPP [RFC5072].
IPV6CP running over one PPP logical channel, the NCPs MUST be
treated as independent of each other and start and terminate WLL-3: If the WAN interface supports PPP encapsulation, in a dual-
independently. stack environment with IPCP and IPV6CP running over one PPP
logical channel, the NCPs MUST be treated as independent of
each other and start and terminate independently.
Address assignment requirements: Address assignment requirements:
WAA-1: The IPv6 CE router MUST support SLAAC [RFC4862]. WAA-1: The IPv6 CE router MUST support SLAAC [RFC4862].
WAA-2: The IPv6 CE router MUST follow the recommendation in WAA-2: The IPv6 CE router MUST follow the recommendation in
[I-D.ietf-6man-ipv6-subnet-model] and in particular the [I-D.ietf-6man-ipv6-subnet-model] and in particular the
handling of the L-bit in the Router Advertisement Prefix handling of the L-flag in the Router Advertisement Prefix
Information Option. Information Option.
WAA-3: The IPv6 CE router MUST support DHCP [RFC3315] client WAA-3: The IPv6 CE router MUST support DHCPv6 [RFC3315] client
behavior. It MUST be able to support the following DHCP behavior.
options: IA_NA, Reconfigure Accept [RFC3315], DNS_SERVERS
[RFC3646].
WAA-4: The IPv6 CE router SHOULD support the DHCP SNTP option WAA-4: The IPv6 CE router MUST be able to support the following
DHCPv6 options: IA_NA, Reconfigure Accept [RFC3315],
DNS_SERVERS [RFC3646].
WAA-5: The IPv6 CE router SHOULD support the DHCPv6 SNTP option
[RFC4075] and the Information Refresh Time Option [RFC4242]. [RFC4075] and the Information Refresh Time Option [RFC4242].
WAA-5: If the IPv6 CE router receives an RA message (described in WAA-6: If the IPv6 CE router receives an RA message (described in
[RFC4861]) with the M-bit set to 1, the IPv6 CE router MUST [RFC4861]) with the M-flag set to 1, the IPv6 CE router MUST
do DHCP address assignment (request an IA_NA option). If the do DHCPv6 address assignment (request an IA_NA option).
IPv6 CE router is unable to assign an address through SLAAC
it MAY do DHCP address assignment (request an IA_NA) even if
the M-bit is set to 0.
WAA-6: If the IPv6 CE router does not acquire a global IPv6 address WAA-7: If the IPv6 CE router is unable to assign address(es) through
from either SLAAC or DHCP, then it MUST create a global IPv6 SLAAC it MAY do DHCPv6 address assignment (request an IA_NA)
address from its delegated prefix and configure that on one even if the M-flag is set to 0.
of its internal virtual network interfaces. As a router the
IPv6 CE router follows the weak host model [RFC1122] and when WAA-8: If the IPv6 CE router does not acquire global IPv6
originating packets out the WAN-interface will use a suitably address(es) from either SLAAC or DHCPv6, then it MUST create
scoped source address from one of its other interfaces. global IPv6 address(es) from its delegated prefix(es) and
configure those on one of its internal virtual network
interfaces.
WAA-9: As a router the IPv6 CE router MUST follow the weak host
model [RFC1122]. When originating packets out an interface
it will use a source address from another of its interfaces
if the outgoing interface does not have an address of
suitable scope.
Prefix Delegation requirements: Prefix Delegation requirements:
WPD-1: The IPv6 CE router MUST support DHCP prefix delegation WPD-1: The IPv6 CE router MUST support DHCPv6 prefix delegation
requesting router behavior as specified in [RFC3633] (IA_PD requesting router behavior as specified in [RFC3633] (IA_PD
option). The IPv6 CE router MUST ask for a prefix large option).
enough to cover all of its LAN interfaces.
WPD-2: The IPv6 CE router MUST always initiate DHCP prefix WPD-2: The IPv6 CE router MAY indicate as a hint to the delegating
delegation, regardless of the M and O-bits in a received router the size of the prefix it requires. If so, it MUST
Router Advertisement. If the IPv6 CE Router initiates DHCP ask for a prefix large enough to assign one /64 for each of
before receiving a Router Advertisement it MUST also request its interfaces rounded up to the nearest nibble and MUST be
an IA_NA option in DHCP. configurable to ask for more.
WPD-3: Absent of other routing information the IPv6 CE router MUST 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.
WPD-4: The IPv6 CE router MUST always initiate DHCPv6 prefix
delegation, regardless of the M and O-flags in a received
Router Advertisement message.
WPD-5: If the IPv6 CE Router initiates DHCPv6 before receiving a
Router Advertisement it MUST also request an IA_NA option in
DHCPv6.
WPD-6: Absent of other routing information the IPv6 CE router MUST
use Router Discovery as specified in [RFC4861] to discover a use Router Discovery as specified in [RFC4861] to discover a
default router and install a default route in its routing default router(s) and install default route(s) in its routing
table with the discovered router's address as the next-hop. table with the discovered router's address as the next-hop.
WPD-4: If the delegated prefix is an aggregate route of multiple, WPD-7: If the delegated prefix(es) are aggregate route(s) of
more-specific routes the IPv6 CE router MUST discard packets multiple, more-specific routes, the IPv6 CE router MUST
that match the aggregate route, but not any of the more- discard packets that match the aggregate route(s), but not
specific routes. In other words, the "next-hop" for the any of the more-specific routes. In other words, the next-
aggregate route should be the null destination. This is hop for the aggregate route(s) should be the null
necessary to prevent forwarding loops when some addresses destination. This is necessary to prevent forwarding loops
covered by the aggregate are not reachable [RFC4632]. The when some addresses covered by the aggregate are not
IPv6 CE Router SHOULD send an ICMPv6 Destination Unreachable reachable [RFC4632].
according to section 3.1 [RFC4443] back to the source of the
packet if the packet is to be dropped due to this rule.
WPD-5: If the IPv6 CE router requests both an IA_NA and an IA_PD in (a) The IPv6 CE router SHOULD send an ICMPv6 Destination
DHCP, it MUST accept an IA_PD in DHCP Advertise/Reply Unreachable according to section 3.1 [RFC4443] back to
the source of the packet, if the packet is to be dropped
due to this rule.
WPD-8: If the IPv6 CE router requests both an IA_NA and an IA_PD in
DHCPv6, it MUST accept an IA_PD in DHCPv6 Advertise/Reply
messages, even if the message does not contain any addresses messages, even if the message does not contain any addresses
(IA_NA options with status code NoAddrsAvail). (IA_NA options with status code equal to NoAddrsAvail).
WPD-6: An IPv6 CE router MUST not by default initiate any dynamic WPD-9: By default an IPv6 CE router MUST NOT initiate any dynamic
routing protocol on its WAN interface. routing protocol on its WAN interface.
4.2. LAN side configuration 4.3. LAN Side Configuration
The IPv6 CE router distributes configuration information obtained The IPv6 CE router distributes configuration information obtained
during WAN interface provisioning to IPv6 hosts and assists IPv6 during WAN interface provisioning to IPv6 hosts and assists IPv6
hosts in obtaining IPv6 addresses. It also supports connectivity of hosts in obtaining IPv6 addresses. It also supports connectivity of
these devices in the absence of any working WAN interface. these devices in the absence of any working WAN interface.
An IPv6 CE router will be expected to support an IPv6 end-user An IPv6 CE router is expected to support an IPv6 end-user network and
network and IPv6 hosts that exhibit the following characteristics: IPv6 hosts that exhibit the following characteristics:
1. Link-local addresses are insufficient for allowing IPv6 1. Link-local addresses are insufficient for allowing IPv6
applications to communicate with each other in the end-user applications to communicate with each other in the end-user
network. The IPv6 CE router will need to enable this network. The IPv6 CE router will need to enable this
communication by providing globally-scoped unicast addresses or communication by providing globally-scoped unicast addresses or
ULAs [RFC4193] whether or not WAN connectivity exists. ULAs [RFC4193] whether or not WAN connectivity exists.
2. IPv6 hosts will be capable of using SLAAC and may be capable of 2. IPv6 hosts should be capable of using SLAAC and may be capable of
using DHCP for acquiring their addresses. using DHCPv6 for acquiring their addresses.
3. IPv6 hosts will use DHCP for other configuration information, 3. IPv6 hosts may use DHCPv6 for other configuration information,
such as the DNS_SERVERS option for acquiring DNS information. such as the DNS_SERVERS option for acquiring DNS information.
Unless otherwise specified these requirements only apply to the IPv6 Unless otherwise specified, the following requirements apply to the
CE router's LAN interfaces. IPv6 CE router's LAN interfaces only.
Requirements: Requirements:
L-1: The IPv6 CE router MUST support ULA addressing [RFC4193]. L-1: The IPv6 CE router MUST support ULA addressing [RFC4193].
L-2: The IPv6 CE router MUST have a ULA prefix that it maintains L-2: The IPv6 CE router MUST have a ULA prefix that it maintains
consistently across reboots. The value of the ULA prefix consistently across reboots.
SHOULD be user configurable.
L-3: The IPv6 CE router by default MUST act as a site border router L-3: The value of the ULA prefix SHOULD be user configurable.
L-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 according to section 4.3 of [RFC4193] and filter packets with
Local IPv6 source or destination addresses accordingly. Local IPv6 source or destination addresses accordingly.
L-4: The IPv6 CE router MUST support router behavior of Neighbor L-5: The IPv6 CE router MUST support router behavior according to
Discovery for IPv6 [RFC4861]. Neighbor Discovery for IPv6 [RFC4861].
L-5: The IPv6 CE router MUST assign a separate /64 from its
delegated prefix (and ULA prefix if configured to provide ULA
addressing) for each of its LAN interfaces. The IPV6 CE
router MUST make the interface an advertising interface
according to [RFC4861]. In router advertisements messages,
the Prefix Information Option's A/L-bits MUST be set to 1 by
default; the A/L bits setting SHOULD be user configurable.
L-6: The IPv6 CE router MUST support a DHCP server [RFC3315] on its
LAN interfaces. It MAY support Stateless Dynamic Host
Configuration Protocol (DHCP) Service for IPv6 [RFC3736].
L-7: The IPv6 CE SHOULD support DHCP address assignment (IA_NA)
[RFC3315].
L-8: Unless the IPv6 CE router is configured to support the DHCP L-6: The IPv6 CE router MUST assign a separate /64 from its
IA_NA option, it SHOULD set M=0 and O=1 in its Router delegated prefix(es) (and ULA prefix if configured to provide
Advertisement messages [RFC4861]. ULA addressing) for each of its LAN interfaces.
L-9: The IPv6 CE router MUST support providing DNS information in L-7: The IPv6 CE router MUST make each LAN interface an advertising
the DHCP DNS_SERVERS option [RFC3646]. interface according to [RFC4861].
L-10: The IPv6 CE router SHOULD pass the additional set of DHCP L-8: In Router Advertisements messages, the Prefix Information
options received from the DHCP client on its WAN interface Option's A and L-flags MUST be set to 1 by default.
from the Service Provider to IPv6 hosts.
4.3. General requirements L-9: The A and L-flags setting SHOULD be user configurable.
The IPv6 CE router is responsible for implementing IPv6 routing; that L-10: The IPv6 CE router MUST support a DHCPv6 server capable of
is, the IPv6 CE router must look up the IPv6 Destination address in IPv6 address assignment according to [RFC3315] OR a stateless
its routing table to decide to which interface it should send the DHCPv6 server according to [RFC3736] on its LAN interfaces.
packet.
In this role, the IPv6 CE router is responsible for ensuring that L-11: Unless the IPv6 CE router is configured to support the DHCPv6
traffic using its ULA addressing does not go out the WAN interface, IA_NA option, it SHOULD set M=0 and O=1 in its Router
and does not originate from the WAN interface. Advertisement messages [RFC4861].
An IPv6 CE router is an IPv6 node according to the IPv6 Node L-12: The IPv6 CE router MUST support providing DNS information in
Requirements [RFC4294] specification. the DHCPv6 DNS_SERVERS option [RFC3646].
The IPv6 CE router MUST NOT forward any IPv6 traffic between its LAN L-13: The IPv6 CE router SHOULD make available a subset of DHCPv6
Interface(s) and its WAN Interface until the router has successfully options (as listed in section 5.3 of [RFC3736]) received from
completed the IPv6 address acquisition process. the DHCPv6 client on its WAN interface to its LAN side DHCPv6
server.
4.4. Security Considerations 4.4. Security Considerations
It is considered a best practice to filter obviously malicious It is considered a best practice to filter obviously malicious
traffic (e.g. spoofed packets, "martian" addresses, etc.). Thus, the traffic (e.g. spoofed packets, "martian" addresses, etc.). Thus, the
IPv6 CE router should support basic stateless egress and ingress IPv6 CE router should support basic stateless egress and ingress
filters. The CE router should also offer mechanisms to filter filters. The CE router should also offer mechanisms to filter
traffic entering the customer network; however, the method by which traffic entering the customer network; however, the method by which
vendors implement configurable packet filtering is beyond the scope vendors implement configurable packet filtering is beyond the scope
of this document. of this document.
skipping to change at page 10, line 36 skipping to change at page 11, line 28
[I-D.ietf-v6ops-cpe-simple-security]. [I-D.ietf-v6ops-cpe-simple-security].
S-2: The IPv6 CE router MUST support ingress filtering in accordance S-2: The IPv6 CE router MUST support ingress filtering in accordance
with [RFC2827](BCP 38) with [RFC2827](BCP 38)
5. Acknowledgements 5. Acknowledgements
Thanks to the following people (in alphabetical order) for their Thanks to the following people (in alphabetical order) for their
guidance and feedback: guidance and feedback:
Mikael Abrahamsson, Merete Asak, Scott Beuker, Rex Bullinger, Brian Mikael Abrahamsson, Merete Asak, Scott Beuker, Mohamed Boucadair, Rex
Carpenter, Remi Denis-Courmont, Alain Durand, Katsunori Fukuoka, Tony Bullinger, Brian Carpenter, Remi Denis-Courmont, Gert Doering, Alain
Hain, Thomas Herbst, Kevin Johns, Stephen Kramer, Victor Kuarsingh, Durand, Katsunori Fukuoka, Tony Hain, Thomas Herbst, Kevin Johns,
Francois-Xavier Le Bail, David Miles, Shin Miyakawa, Jean-Francois Stephen Kramer, Victor Kuarsingh, Francois-Xavier Le Bail, David
Mule, Michael Newbery, Carlos Pignataro, John Pomeroy, Antonio Miles, Shin Miyakawa, Jean-Francois Mule, Michael Newbery, Carlos
Querubin, Teemu Savolainen, Matt Schmitt, Hiroki Sato, Mark Townsley, Pignataro, John Pomeroy, Antonio Querubin, Teemu Savolainen, Matt
Bernie Volz, James Woodyatt, Dan Wing and Cor Zwart Schmitt, Hiroki Sato, Mark Townsley, Bernie Volz, James Woodyatt, Dan
Wing and Cor Zwart
This draft is based in part on CableLabs' eRouter specification. The This draft is based in part on CableLabs' eRouter specification. The
authors wish to acknowledge the additional contributors from the authors wish to acknowledge the additional contributors from the
eRouter team: eRouter team:
Ben Bekele, Amol Bhagwat, Ralph Brown, Eduardo Cardona, Margo Dolas, Ben Bekele, Amol Bhagwat, Ralph Brown, Eduardo Cardona, Margo Dolas,
Toerless Eckert, Doc Evans, Roger Fish, Michelle Kuska, Diego Toerless Eckert, Doc Evans, Roger Fish, Michelle Kuska, Diego
Mazzola, John McQueen, Harsh Parandekar, Michael Patrick, Saifur Mazzola, John McQueen, Harsh Parandekar, Michael Patrick, Saifur
Rahman, Lakshmi Raman, Ryan Ross, Ron da Silva, Madhu Sudan, Dan Rahman, Lakshmi Raman, Ryan Ross, Ron da Silva, Madhu Sudan, Dan
Torbet and Greg White Torbet and Greg White
skipping to change at page 11, line 18 skipping to change at page 12, line 11
The following people have participated as co-authors or provided The following people have participated as co-authors or provided
substantial contributions to this document: Ralph Droms, Kirk substantial contributions to this document: Ralph Droms, Kirk
Erichsen, Fred Baker, Jason Weil, Lee Howard, Jean-Francois Tremblay, Erichsen, Fred Baker, Jason Weil, Lee Howard, Jean-Francois Tremblay,
Yiu Lee, John Jason Brzozowski and Heather Kirksey. Yiu Lee, John Jason Brzozowski and Heather Kirksey.
7. IANA Considerations 7. IANA Considerations
This memo includes no request to IANA. This memo includes no request to IANA.
8. Normative References 8. References
8.1. Normative References
[I-D.ietf-6man-ipv6-subnet-model] [I-D.ietf-6man-ipv6-subnet-model]
Singh, H., Beebee, W., and E. Nordmark, "IPv6 Subnet Singh, H., Beebee, W., and E. Nordmark, "IPv6 Subnet
Model: the Relationship between Links and Subnet Model: the Relationship between Links and Subnet
Prefixes", draft-ietf-6man-ipv6-subnet-model-06 (work in Prefixes", draft-ietf-6man-ipv6-subnet-model-07 (work in
progress), November 2009. progress), December 2009.
[I-D.ietf-v6ops-cpe-simple-security] [I-D.ietf-v6ops-cpe-simple-security]
Woodyatt, J., "Recommended Simple Security Capabilities in Woodyatt, J., "Recommended Simple Security Capabilities in
Customer Premises Equipment for Providing Residential IPv6 Customer Premises Equipment for Providing Residential IPv6
Internet Service", draft-ietf-v6ops-cpe-simple-security-08 Internet Service", draft-ietf-v6ops-cpe-simple-security-08
(work in progress), October 2009. (work in progress), October 2009.
[RFC1122] Braden, R., "Requirements for Internet Hosts - [RFC1122] Braden, R., "Requirements for Internet Hosts -
Communication Layers", STD 3, RFC 1122, October 1989. Communication Layers", STD 3, RFC 1122, October 1989.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet [RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet
Networks", RFC 2464, December 1998. Networks", RFC 2464, December 1998.
[RFC2516] Mamakos, L., Lidl, K., Evarts, J., Carrel, D., Simone, D.,
and R. Wheeler, "A Method for Transmitting PPP Over
Ethernet (PPPoE)", RFC 2516, February 1999.
[RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering: [RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering:
Defeating Denial of Service Attacks which employ IP Source Defeating Denial of Service Attacks which employ IP Source
Address Spoofing", BCP 38, RFC 2827, May 2000. Address Spoofing", BCP 38, RFC 2827, May 2000.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003. IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
Host Configuration Protocol (DHCP) version 6", RFC 3633, Host Configuration Protocol (DHCP) version 6", RFC 3633,
skipping to change at page 13, line 15 skipping to change at page 14, line 5
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862, September 2007. Address Autoconfiguration", RFC 4862, September 2007.
[RFC4864] Van de Velde, G., Hain, T., Droms, R., Carpenter, B., and [RFC4864] Van de Velde, G., Hain, T., Droms, R., Carpenter, B., and
E. Klein, "Local Network Protection for IPv6", RFC 4864, E. Klein, "Local Network Protection for IPv6", RFC 4864,
May 2007. May 2007.
[RFC5072] S.Varada, Haskins, D., and E. Allen, "IP Version 6 over [RFC5072] S.Varada, Haskins, D., and E. Allen, "IP Version 6 over
PPP", RFC 5072, September 2007. PPP", RFC 5072, September 2007.
Appendix A. Changes in revision 3 8.2. Informative References
o Added "the CPE Router SHOULD send an ICMPv6 Destination
Unreachable ([RFC4443] section 3.1) back to the source of the
packet if the packet is to be dropped due to aggregate null
route."
o Clarified that if IPV6CP and IPCP run over the same PPP session
they should be treated independently.
o Removed RFC2460 in the section of RFCs that SHOULD be supported.
o Clarified that the router acts as a host for the purposes of
address assignment. Not for any other ND function e.g Redirects.
o Improved default router selection / default route RIB insertion [I-D.ietf-behave-v6v4-framework]
text. Baker, F., Li, X., Bao, C., and K. Yin, "Framework for
IPv4/IPv6 Translation",
draft-ietf-behave-v6v4-framework-04 (work in progress),
December 2009.
o Added text describing that the weak host model has to be supported [UPnP-IGD]
in the unnumbered WAN case. UPnP Forum, "Universal Plug and Play (UPnP) Internet
Gateway Device (IGD)", November 2001,
<http://www.upnp.org/standardizeddcps/igd.asp>.
Authors' Addresses Authors' Addresses
Hemant Singh Hemant Singh
Cisco Systems, Inc. Cisco Systems, Inc.
1414 Massachusetts Ave. 1414 Massachusetts Ave.
Boxborough, MA 01719 Boxborough, MA 01719
USA USA
Phone: +1 978 936 1622 Phone: +1 978 936 1622
skipping to change at page 14, line 36 skipping to change at page 15, line 18
USA USA
Email: barbara.stark@att.com Email: barbara.stark@att.com
Ole Troan (editor) Ole Troan (editor)
Cisco Systems, Inc. Cisco Systems, Inc.
Veversmauet 8 Veversmauet 8
N-5017 BERGEN, N-5017 BERGEN,
Norway Norway
Phone:
Email: ot@cisco.com Email: ot@cisco.com
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