draft-ietf-v6ops-6204bis-01.txt   draft-ietf-v6ops-6204bis-02.txt 
Network Working Group H. Singh Network Working Group H. Singh
Internet-Draft W. Beebee Internet-Draft W. Beebee
Updates: 6204 (if approved) Cisco Systems, Inc. Updates: 6204 (if approved) Cisco Systems, Inc.
Intended status: Standards Track C. Donley Intended status: Informational C. Donley
Expires: April 20, 2012 CableLabs Expires: May 3, 2012 CableLabs
B. Stark B. Stark
AT&T AT&T
O. Troan, Ed. O. Troan, Ed.
Cisco Systems, Inc. Cisco Systems, Inc.
October 18, 2011 October 31, 2011
Basic Requirements for IPv6 Customer Edge Routers Basic Requirements for IPv6 Customer Edge Routers
draft-ietf-v6ops-6204bis-01 draft-ietf-v6ops-6204bis-02
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 basic provisioning of an IPv6 CE router and the provisioning on the basic provisioning of an IPv6 CE router and the provisioning
of IPv6 hosts attached to it. The document also covers IP transition of IPv6 hosts attached to it. The document also covers IP transition
technologies and transition technologies coexistence. Two transition technologies and transition technologies coexistence. Two transition
technologies in 6rd [RFC5969] and DS-Lite [RFC6333] are covered in technologies in RFC 5969's 6rd and RFC 6333's DS-Lite. are covered in
the document. the document.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted 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). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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."
This Internet-Draft will expire on April 20, 2012. This Internet-Draft will expire on May 3, 2012.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2011 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
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 28 skipping to change at page 2, line 28
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
3.2.1. Local Communication . . . . . . . . . . . . . . . . . 6 3.2.1. Local Communication . . . . . . . . . . . . . . . . . 6
4. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 7 4. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. General Requirements . . . . . . . . . . . . . . . . . . . 7 4.1. General Requirements . . . . . . . . . . . . . . . . . . . 7
4.2. WAN-Side Configuration . . . . . . . . . . . . . . . . . . 8 4.2. WAN-Side Configuration . . . . . . . . . . . . . . . . . . 8
4.3. LAN-Side Configuration . . . . . . . . . . . . . . . . . . 11 4.3. LAN-Side Configuration . . . . . . . . . . . . . . . . . . 11
4.4. Transition Technologies Support . . . . . . . . . . . . . 13 4.4. Transition Technologies Support . . . . . . . . . . . . . 13
4.4.1. 6rd . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.4.1. 6rd . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.4.2. Dual-Stack(DS)-Lite . . . . . . . . . . . . . . . . . 14 4.4.2. Dual-Stack Lite(DS-Lite) . . . . . . . . . . . . . . . 14
4.4.3. Transition Technologies Coexistence . . . . . . . . . 15 4.4.3. Transition Technologies Coexistence . . . . . . . . . 15
4.5. Security Considerations . . . . . . . . . . . . . . . . . 16 4.5. Security Considerations . . . . . . . . . . . . . . . . . 16
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 17 6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 17
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1. Normative References . . . . . . . . . . . . . . . . . . . 17 7.1. Normative References . . . . . . . . . . . . . . . . . . . 17
7.2. Informative References . . . . . . . . . . . . . . . . . . 19 7.2. Informative References . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20 Appendix A. Changes from RFC 6204 . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction 1. Introduction
This document defines basic IPv6 features for a residential or small- This document defines basic IPv6 features for a residential or small-
office router, referred to as an IPv6 CE router. Typically, these office router, referred to as an IPv6 CE router. Typically, these
routers also support IPv4. routers also support IPv4.
Mixed environments of dual-stack hosts and IPv6-only hosts (behind 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 the CE router) can be more complex if the IPv6-only devices are using
a translator to access IPv4 servers [RFC6144]. Support for such a translator to access IPv4 servers [RFC6144]. Support for such
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its LAN interface(s) and its WAN interface until the router has its LAN interface(s) and its WAN interface until the router has
successfully completed the IPv6 address acquisition process. successfully completed the IPv6 address acquisition process.
G-4: By default, an IPv6 CE router that has no default router(s) on 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 its WAN interface MUST NOT advertise itself as an IPv6 default
router on its LAN interfaces. That is, the "Router Lifetime" router on its LAN interfaces. That is, the "Router Lifetime"
field is set to zero in all Router Advertisement messages it field is set to zero in all Router Advertisement messages it
originates [RFC4861]. originates [RFC4861].
G-5: By default, if the IPv6 CE router is an advertising router and G-5: By default, if the IPv6 CE router is an advertising router and
loses its IPv6 default router(s) on the WAN interface, it MUST loses its IPv6 default router(s) and/or detects loss of
explicitly invalidate itself as an IPv6 default router on each connectivity on the WAN interface, it MUST explicitly
of its advertising interfaces by immediately transmitting one invalidate itself as an IPv6 default router on each of its
or more Router Advertisement messages with the "Router advertising interfaces by immediately transmitting one or more
Lifetime" field set to zero [RFC4861]. Router Advertisement messages with the "Router Lifetime" field
set to zero [RFC4861].
4.2. WAN-Side Configuration 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 that supports all commonly used architectures. provider and that supports all commonly used architectures.
IPv6 Neighbor Discovery and DHCPv6 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-
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WAA-5: The IPv6 CE router SHOULD support the DHCPv6 Simple Network WAA-5: The IPv6 CE router SHOULD support the DHCPv6 Simple Network
Time Protocol (SNTP) option [RFC4075] and the Information Time Protocol (SNTP) option [RFC4075] and the Information
Refresh Time option [RFC4242]. Refresh Time option [RFC4242].
WAA-6: If the IPv6 CE router receives a Router Advertisement message WAA-6: If the IPv6 CE router receives a Router Advertisement message
(described in [RFC4861]) with the M flag set to 1, the IPv6 (described in [RFC4861]) with the M flag set to 1, the IPv6
CE router MUST do DHCPv6 address assignment (request an IA_NA CE router MUST do DHCPv6 address assignment (request an IA_NA
option). option).
WAA-7: If the IPv6 CE router is unable to assign address(es) through WAA-7: If the IPv6 CE router does not acquire global IPv6
SLAAC, it MAY do DHCPv6 address assignment (request an IA_NA
option) even if the M flag is set to 0.
WAA-8: If the IPv6 CE router does not acquire global IPv6
address(es) from either SLAAC or DHCPv6, then it MUST create address(es) from either SLAAC or DHCPv6, then it MUST create
global IPv6 address(es) from its delegated prefix(es) and global IPv6 address(es) from its delegated prefix(es) and
configure those on one of its internal virtual network configure those on one of its internal virtual network
interfaces. interfaces unless configured to require a global IPv6 address
on the WAN interface.
WAA-8: The IPv6 CE router MUST set SOL_MAX_RT (specified by
[RFC3315]) to 7200 seconds.
WAA-9: As a router, the IPv6 CE router MUST follow the weak host WAA-9: As a router, the IPv6 CE router MUST follow the weak host
(Weak ES) model [RFC1122]. When originating packets from an (Weak ES) model [RFC1122]. When originating packets from an
interface, it will use a source address from another one of interface, it will use a source address from another one of
its interfaces if the outgoing interface does not have an its interfaces if the outgoing interface does not have an
address of suitable scope. address of suitable scope.
Prefix delegation requirements: Prefix delegation requirements:
WPD-1: The IPv6 CE router MUST support DHCPv6 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). option).
WPD-2: The IPv6 CE router MAY indicate as a hint to the delegating 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 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 ask for a prefix large enough to assign one /64 for each of
its interfaces, rounded up to the nearest nibble, and MUST be its interfaces, rounded up to the nearest nibble, and SHOULD
configurable to ask for more. be configurable to ask for more.
WPD-3: The IPv6 CE router MUST be prepared to accept a delegated 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 prefix size different from what is given in the hint. If the
delegated prefix is too small to address all of its delegated prefix is too small to address all of its
interfaces, the IPv6 CE router SHOULD log a system management interfaces, the IPv6 CE router SHOULD log a system management
error. error.
WPD-4: The IPv6 CE router MUST always initiate DHCPv6 prefix WPD-4: By default, the IPv6 CE router MUST initiate DHCPv6 prefix
delegation, regardless of the M and O flags in a received delegation when either the M or O flags are set to 1 in a
Router Advertisement message. received Router Advertisement message.
WPD-5: If the IPv6 CE router initiates DHCPv6 before receiving a WPD-5: If the IPv6 CE router is configured to initiate DHCPv6 before
Router Advertisement, it MUST also request an IA_NA option in receiving a Router Advertisement, it MUST also request an
DHCPv6. IA_NA option in DHCPv6.
WPD-6: If the delegated prefix(es) are aggregate route(s) of WPD-6: If the delegated prefix(es) are aggregate route(s) of
multiple, more-specific routes, the IPv6 CE router MUST multiple, more-specific routes, the IPv6 CE router MUST
discard packets that match the aggregate route(s), but not discard packets that match the aggregate route(s), but not
any of the more-specific routes. In other words, the next any of the more-specific routes. In other words, the next
hop for the aggregate route(s) should be the null hop for the aggregate route(s) should be the null
destination. This is necessary to prevent forwarding loops destination. This is necessary to prevent forwarding loops
when some addresses covered by the aggregate are not when some addresses covered by the aggregate are not
reachable [RFC4632]. reachable [RFC4632].
(a) The IPv6 CE router SHOULD send an ICMPv6 Destination (a) The IPv6 CE router SHOULD send an ICMPv6 Destination
Unreachable message in accordance with Section 3.1 of Unreachable message in accordance with Section 3.1 of
[RFC4443] back to the source of the packet, if the [RFC4443] back to the source of the packet, if the
packet is to be dropped due to this rule. packet is to be dropped due to this rule.
WPD-7: If the IPv6 CE router requests both an IA_NA and an IA_PD WPD-7: 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 option in DHCPv6, it MUST accept an IA_PD option in DHCPv6
Advertise/Reply messages, even if the message does not Advertise/Reply messages, even if the message does not
contain any addresses. contain any addresses, unless configured to only obtain its
WAN IPv6 address via DHCPv6.
WPD-8: By default, an IPv6 CE router MUST NOT initiate any dynamic WPD-8: By default, an IPv6 CE router MUST NOT initiate any dynamic
routing protocol on its WAN interface. routing protocol on its WAN interface.
4.3. 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.
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IPv6 address assignment according to [RFC3315] OR a stateless IPv6 address assignment according to [RFC3315] OR a stateless
DHCPv6 server according to [RFC3736] on its LAN interfaces. DHCPv6 server according to [RFC3736] on its LAN interfaces.
L-9: Unless the IPv6 CE router is configured to support the DHCPv6 L-9: Unless the IPv6 CE router is configured to support the DHCPv6
IA_NA option, it SHOULD set the M flag to 0 and the O flag to IA_NA option, it SHOULD set the M flag to 0 and the O flag to
1 in its Router Advertisement messages [RFC4861]. 1 in its Router Advertisement messages [RFC4861].
L-10: The IPv6 CE router MUST support providing DNS information in L-10: The IPv6 CE router MUST support providing DNS information in
the DHCPv6 DNS_SERVERS and DOMAIN_LIST options [RFC3646]. the DHCPv6 DNS_SERVERS and DOMAIN_LIST options [RFC3646].
L-11: The IPv6 CE router SHOULD support providing DNS information in L-11: The IPv6 CE router MUST support providing DNS information in
the Router Advertisement Recursive DNS Server (RDNSS) and DNS the Router Advertisement Recursive DNS Server (RDNSS) and DNS
Search List (DNSSL) options as specified in [RFC6106]. Search List (DNSSL) options as specified in [RFC6106].
L-12: The IPv6 CE router SHOULD make available a subset of DHCPv6 L-12: The IPv6 CE router SHOULD make available a subset of DHCPv6
options (as listed in Section 5.3 of [RFC3736]) received from options (as listed in Section 5.3 of [RFC3736]) received from
the DHCPv6 client on its WAN interface to its LAN-side DHCPv6 the DHCPv6 client on its WAN interface to its LAN-side DHCPv6
server. server.
L-13: If the delegated prefix changes, i.e., the current prefix is L-13: If the delegated prefix changes, i.e., the current prefix is
replaced with a new prefix without any overlapping time replaced with a new prefix without any overlapping time
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prefix during 6rd configuration, and sub-delegates the 6rd delegated prefix during 6rd configuration, and sub-delegates the 6rd delegated
prefix to devices in the LAN. prefix to devices in the LAN.
The IPv6 CE Router SHOULD implement 6rd functionality as specified in The IPv6 CE Router SHOULD implement 6rd functionality as specified in
[RFC5969]. [RFC5969].
6rd requirements: 6rd requirements:
6RD-1: If the IPv6 CE Router implements 6rd functionality, the CE 6RD-1: If the IPv6 CE Router implements 6rd functionality, the CE
Router WAN interface MUST support at least one 6rd Virtual Router WAN interface MUST support at least one 6rd Virtual
Interface and 6rd CE functionality as specified in [RFC5969]. Interface.
6RD-2: If the IPv6 CE Router implements 6rd CE functionality, it 6RD-2: If the IPv6 CE router implements 6rd functionality, it MUST
MUST support user-entered configuration and using the 6rd support 6rd configuration via the 6rd DHCPv4 Option (212) and
DHCPv4 Option (212) for 6rd configuration. The IPv6 CE if the IPv6 CE router is capable of automated configuration
Router MAY use other mechanisms to configure 6rd parameters. of IPv4 through IPCP (i.e., over a PPP connection), it MUST
support user-entered configuration of 6rd. The IPv6 CE
router MAY use other mechanisms to configure 6rd parameters.
Such mechanisms are outside the scope of this document. Such mechanisms are outside the scope of this document.
6RD-3: If the CE router implements 6rd functionality, it MUST allow 6RD-3: If the CE router implements 6rd functionality, it MUST allow
the user to specify whether all IPv6 traffic goes to the 6rd the user to specify whether all IPv6 traffic goes to the 6rd
Border Relay, or whether IPv6 traffic to other destinations Border Relay, or whether IPv6 traffic to other destinations
within the same 6rd domain are routed directly to those within the same 6rd domain are routed directly to those
destinations. The CE router MAY use other mechanisms to destinations. The CE router MAY use other mechanisms to
configure this. Such mechanisms are outside the scope of configure this. Such mechanisms are outside the scope of
this document. this document.
6RD-4: If 6rd is operational on the IPv6 CE Router, multicast data 6RD-4: If 6rd is operational on the IPv6 CE Router, multicast data
MUST NOT be sent on any 6rd tunnel. MUST NOT be sent on any 6rd tunnel.
6RD-5: The CE Router MUST NOT forward 6RD traffic over a DS-Lite 6RD-5: The CE Router MUST NOT forward 6RD traffic over a DS-Lite
([RFC6333]) tunnel. ([RFC6333]) tunnel.
4.4.2. Dual-Stack(DS)-Lite 4.4.2. Dual-Stack Lite(DS-Lite)
Even as users migrate from IPv4 to IPv6 addressing, a significant Even as users migrate from IPv4 to IPv6 addressing, a significant
percentage of Internet resources and content will remain accessible percentage of Internet resources and content will remain accessible
only through IPv4. Also, many end-user devices will only support only through IPv4. Also, many end-user devices will only support
IPv4. As a consequence, Service Providers require mechanisms to IPv4. As a consequence, Service Providers require mechanisms to
allow customers to continue to access content and resources using allow customers to continue to access content and resources using
IPv4 even after the last IPv4 allocations have been fully depleted. IPv4 even after the last IPv4 allocations have been fully depleted.
One technology that can be used for IPv4 address extension is DS- One technology that can be used for IPv4 address extension is DS-
Lite. Lite.
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Router MAY use other mechanisms to configure DS-Lite Router MAY use other mechanisms to configure DS-Lite
parameters. Such mechanisms are outside the scope of this parameters. Such mechanisms are outside the scope of this
document. document.
DLW-3: IPv6 CE Router MUST NOT perform IPv4 Network Address DLW-3: IPv6 CE Router MUST NOT perform IPv4 Network Address
Translation (NAT) on IPv4 traffic encapsulated using DS-Lite. Translation (NAT) on IPv4 traffic encapsulated using DS-Lite.
DLW-4: If the IPv6 CE Router is configured with a public IPv4 DLW-4: If the IPv6 CE Router is configured with a public IPv4
address on its WAN interface, where public IPv4 address is address on its WAN interface, where public IPv4 address is
defined as any address which is not in the private IP address defined as any address which is not in the private IP address
space specified in [RFC1918] and also not in the reserved IP space specified in [RFC5735] and also not in the reserved IP
address space specified in [RFC6333], then the IPv6 CE Router address space specified in [RFC6333], then the IPv6 CE Router
MUST disable the DS-Lite B4 element. MUST disable the DS-Lite B4 element.
DLW-5: If DS-Lite is operational on the IPv6 CE Router, multicast DLW-5: If DS-Lite is operational on the IPv6 CE Router, multicast
data MUST NOT be sent on any DS-Lite tunnel. data MUST NOT be sent on any DS-Lite tunnel.
DLW-6: The CE Router MUST NOT forward DS-Lite traffic over a 6RD DLW-6: The CE Router MUST NOT forward DS-Lite traffic over a 6RD
tunnel. tunnel.
4.4.3. Transition Technologies Coexistence 4.4.3. Transition Technologies Coexistence
Supporting transition technologies that may coexist with native
service requires control over provisioning and sunsetting. Some
guidelines follow:
1. Initiate native IPv4/IPv6 provisioning (e.g. via DHCP) 1. Initiate native IPv4/IPv6 provisioning (e.g. via DHCP)
simultaneously. simultaneously.
2. After IPv4 provisioning completes, if 6rd parameters are obtained 2. After IPv4 provisioning completes, if 6rd parameters are obtained
from the DHCPv4 transaction or configured on the device, initiate from the DHCPv4 transaction or configured on the device, initiate
6rd. 6rd.
3. After IPv6 provisioning completes, if DS-Lite parameters are 3. After IPv6 provisioning completes, if DS-Lite parameters are
obtained from the DHCPv6 transaction or configured on the device, obtained from the DHCPv6 transaction or configured on the device,
initiate DS-Lite. initiate DS-Lite.
4. Routes over the DS-Lite tunnel always have a higher 4. Routes over the DS-Lite tunnel always have a higher
administrative distance than native IPv4 routes. administrative distance than native IPv4 routes.
5. Routing between 6rd and native IPv6 uses Policy Based Routing 5. Selection of 6rd tunnel or native IPv6 output interface on the CE
(PBR). PBR is specified in [RFC1102] and [RFC1104]. A small router is determined by the source IPv6 address of the packet
subset of PBR MUST be implemented by the device. The small from a host.
subset matches source IPv6 prefix to route packets over 6rd or
native IPv6. With 6rd and native IPv6 upstream links, the hosts 6. The CE router messages to the host the use of native IPv6 in
in the home LAN also need to be provided a Source Address preference to 6rd.
Selection (SAS) Policy Table specified in [RFC3484]. Both the
SAS Policy Table and PBR can be automatically configured to
prefer native IPv6 connectivity instead of 6rd if both are
available. One way of distributing a SAS Policy Table is
described in [SAS-POLICY-TABLE].
During a sunsetting activity such as deprecating 6rd and moving to During a sunsetting activity such as deprecating 6rd and moving to
native IPv6, due to the two hours rule specified in [RFC4862], the native IPv6, the IPv6 CE router MUST immediately advertise the 6rd
6rd and the native IPv6 prefix will coexist in the home network. The prefix with a Preferred Lifetime of zero and a Valid Lifetime of the
two hours rule specified in section 5.5.3 of [RFC4862] causes any lower of the current Valid Lifetime and two hours (which must be
deprecated prefix to linger on the node even when an RA has sent a decremented in real time) in a Router Advertisement message as
Valid Lifetime of zero to expire the prefix to the node. During such described in Section 5.5.3, (e) of [RFC4862]. Due to the two hours
coexistence of multiple prefixes, the CE router sends an ICMPv6 error rule specified in [RFC4862], the 6rd and the native IPv6 prefix will
for packets sourced or destined related to the deprecated prefix. coexist in the home network. The two hours rule specified in section
Note this document already includes text in bullet L-14 in section 5.5.3 of [RFC4862] causes any deprecated prefix to linger on the node
4.3 for such a provision. even when an RA has sent a Preferred Lifetime of zero to expire the
prefix to the node. During such coexistence of multiple prefixes,
the CE router sends an ICMPv6 error for packets sourced or destined
related to the deprecated prefix. Note this document already
includes text in bullet L-14 in section 4.3 for such a provision.
4.5. Security Considerations 4.5. 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, traffic (e.g., spoofed packets, "Martian" addresses, etc.). Thus,
the IPv6 CE router ought to support basic stateless egress and the IPv6 CE router ought to support basic stateless egress and
ingress filters. The CE router is also expected to offer mechanisms ingress filters. The CE router is also expected to offer mechanisms
to filter traffic entering the customer network; however, the method to filter traffic entering the customer network; however, the method
by which vendors implement configurable packet filtering is beyond by which vendors implement configurable packet filtering is beyond
the scope of this document. the scope of this document.
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S-1: The IPv6 CE router SHOULD support [RFC6092]. In particular, S-1: The IPv6 CE router SHOULD support [RFC6092]. In particular,
the IPv6 CE router SHOULD support functionality sufficient for the IPv6 CE router SHOULD support functionality sufficient for
implementing the set of recommendations in [RFC6092], implementing the set of recommendations in [RFC6092],
Section 4. This document takes no position on whether such Section 4. This document takes no position on whether such
functionality is enabled by default or mechanisms by which functionality is enabled by default or mechanisms by which
users would configure it. users would configure it.
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 BCP 38 [RFC2827]. with BCP 38 [RFC2827].
S-3: When 6rd is enabled on the device, a firewall SHOULD provide S-3: If the IPv6 CE router firewall is configured to filter incoming
the capability to filter decapsulated packets from the 6rd tunneled data, the firewall SHOULD provide the capability to
tunnel. filter decapsulated packets from a tunnel.
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, Tore Anderson, Merete Asak, Scott Beuker, Mohamed Mikael Abrahamsson, Tore Anderson, Merete Asak, Scott Beuker, Mohamed
Boucadair, Rex Bullinger, Brian Carpenter, Tassos Chatzithomaoglou, Boucadair, Rex Bullinger, Brian Carpenter, Tassos Chatzithomaoglou,
Lorenzo Colitti, Remi Denis-Courmont, Gert Doering, Alain Durand, Lorenzo Colitti, Remi Denis-Courmont, Gert Doering, Alain Durand,
Katsunori Fukuoka, Tony Hain, Thomas Herbst, Kevin Johns, Erik Kline, Katsunori Fukuoka, Tony Hain, Thomas Herbst, Kevin Johns, Erik Kline,
skipping to change at page 19, line 17 skipping to change at page 19, line 23
[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.
[RFC5735] Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses",
BCP 153, RFC 5735, January 2010.
[RFC5942] Singh, H., Beebee, W., and E. Nordmark, "IPv6 Subnet [RFC5942] Singh, H., Beebee, W., and E. Nordmark, "IPv6 Subnet
Model: The Relationship between Links and Subnet Model: The Relationship between Links and Subnet
Prefixes", RFC 5942, July 2010. Prefixes", RFC 5942, July 2010.
[RFC5969] Townsley, W. and O. Troan, "IPv6 Rapid Deployment on IPv4 [RFC5969] Townsley, W. and O. Troan, "IPv6 Rapid Deployment on IPv4
Infrastructures (6rd) -- Protocol Specification", Infrastructures (6rd) -- Protocol Specification",
RFC 5969, August 2010. RFC 5969, August 2010.
[RFC6092] Woodyatt, J., "Recommended Simple Security Capabilities in [RFC6092] Woodyatt, J., "Recommended Simple Security Capabilities in
Customer Premises Equipment (CPE) for Providing Customer Premises Equipment (CPE) for Providing
skipping to change at page 20, line 13 skipping to change at page 20, line 21
March 2011. March 2011.
[MULTIHOMING-WITHOUT-NAT] [MULTIHOMING-WITHOUT-NAT]
Troan, O., Ed., Miles, D., Matsushima, S., Okimoto, T., Troan, O., Ed., Miles, D., Matsushima, S., Okimoto, T.,
and D. Wing, "IPv6 Multihoming without Network Address and D. Wing, "IPv6 Multihoming without Network Address
Translation", Work in Progress, December 2010. Translation", Work in Progress, December 2010.
[RFC6144] Baker, F., Li, X., Bao, C., and K. Yin, "Framework for [RFC6144] Baker, F., Li, X., Bao, C., and K. Yin, "Framework for
IPv4/IPv6 Translation", RFC 6144, March 2011. IPv4/IPv6 Translation", RFC 6144, March 2011.
[SAS-POLICY-TABLE]
Matsumoto, A., Fujisaki, T., Kato, J., and T. Chown,
"Distributing Address Selection Policy using DHCPv6", Work
in Progress, June 2011.
[UPnP-IGD] [UPnP-IGD]
UPnP Forum, "Universal Plug and Play (UPnP) Internet UPnP Forum, "Universal Plug and Play (UPnP) Internet
Gateway Device (IGD)", November 2001, Gateway Device (IGD)", November 2001,
<http://www.upnp.org/>. <http://www.upnp.org/>.
Appendix A. Changes from RFC 6204
1. Added IP transition technologies available in RFC form.
2. Added IP transition technologies coexistence.
3. Changed bullet G-5 to augment the condition of losing IPv6
default router(s) with loss of connectivity.
4. Removed bullet WAA-7 due to not reaching consensus by various
service provider standards bodies. The removal of text does not
remove any critical functionality from the CE specification.
5. Changed bullet WAA-8 to qualify WAN behavior only if not
configured to perform DHCPv6. This way a deployment specific
profile can mandate DHCPv6 numbered WAN wihout conflicting with
this document.
6. Changed the WPD-2 bullet from MUST be configurable to SHOULD be
configurable.
7. Changed bullet WPD-4 for a default behavior without compromising
any prior specification of the CE device. The change was needed
by a specific layer 1 deployment which wanted to specify a MUST
for DHCPv6 in their layer 1 profile and not conflict with this
document.
8. Changed bullet WPD-7 to qualify text for DHCPv6.
9. Added a new WAN DHCPv6 requirement for SOL_MAX_RT of DHCPv6 so
that if an service provider does not have DHCPv6 service enabled
CE routers do not send too frequent DHCPv6 requests to the
service provider DHCPv6 server.
10. Changed bullet L-11 from SHOULD provide DNS options in the RA to
MUST provide DNS option in the RA.
11. New bullet added to the Security Considerations section due to
addition of transition technology. The CE router filters
decapsulated 6rd data.
12. Minor change involved changing ICMP to ICMPv6.
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
EMail: shemant@cisco.com EMail: shemant@cisco.com
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