Network Working Group J. Arkko
Internet-Draft Ericsson
Intended status: Informational A. Brandt
Expires: August 2, 2012 Sigma Designs
T. Chown
University of Southampton
J. Weil
Time Warner Cable
O. Troan
Cisco Systems, Inc.
January 30, 2012
Home Networking Architecture for IPv6
draft-ietf-homenet-arch-01
Abstract
This text describes evolving networking technology within small
"residential home" networks. The goal of this memo is to define the
architecture for IPv6-based home networking and the associated
principles, considerations and requirements. The text highlights the
impact of IPv6 on home networking, illustrates topology scenarios,
and shows how standard IPv6 mechanisms and addressing can be employed
in home networking. The architecture describes the need for specific
protocol extensions for certain additional functionality. It is
assumed that the IPv6 home network is not actively managed, and runs
as an IPv6-only or dual-stack network. There are no recommendations
in this text for the IPv4 part of the network.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 2, 2012.
Copyright Notice
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Copyright (c) 2012 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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Terminology and Abbreviations . . . . . . . . . . . . . . 5
2. Effects of IPv6 on Home Networking . . . . . . . . . . . . . . 5
2.1. Multiple subnets and routers . . . . . . . . . . . . . . . 5
2.2. Multi-Addressing of devices . . . . . . . . . . . . . . . 6
2.3. Unique Local Addresses (ULAs) . . . . . . . . . . . . . . 6
2.4. Security, Borders, and the elimination of NAT . . . . . . 7
2.5. Naming, and manual configuration of IP addresses . . . . . 9
3. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1. Network Models . . . . . . . . . . . . . . . . . . . . . . 9
3.1.1. A: Single ISP, Single CER, Single subnet . . . . . . . 10
3.1.2. B: Single ISP, Single CER, Multiple subnets . . . . . 11
3.1.3. C: Single ISP, Single CER, Multiple internal
subnets . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.4. D: Two ISPs, Two CERs, Shared subnets with
multiple internal routers . . . . . . . . . . . . . . 14
3.1.5. E: Two ISPs, One CER, Isolated subnets with
multiple internal routers . . . . . . . . . . . . . . 15
3.1.6. F: Two ISPs, One CER, Shared subnets with multiple
internal routers . . . . . . . . . . . . . . . . . . . 16
3.2. Determining the Requirements . . . . . . . . . . . . . . . 16
3.3. Considerations . . . . . . . . . . . . . . . . . . . . . . 17
3.3.1. Multihoming . . . . . . . . . . . . . . . . . . . . . 17
3.3.2. Quality of Service in multi-service home networks . . 19
3.3.3. Privacy considerations . . . . . . . . . . . . . . . . 19
3.4. Principles . . . . . . . . . . . . . . . . . . . . . . . . 19
3.4.1. Reuse existing protocols . . . . . . . . . . . . . . . 19
3.4.2. Dual-stack Operation . . . . . . . . . . . . . . . . . 20
3.4.3. Largest Possible Subnets . . . . . . . . . . . . . . . 21
3.4.4. Transparent End-to-End Communications . . . . . . . . 21
3.4.5. IP Connectivity between All Nodes . . . . . . . . . . 22
3.4.6. Routing functionality . . . . . . . . . . . . . . . . 23
3.4.7. Self-Organising . . . . . . . . . . . . . . . . . . . 25
3.4.8. Fewest Topology Assumptions . . . . . . . . . . . . . 27
3.4.9. Naming and Service Discovery . . . . . . . . . . . . . 27
3.4.10. Proxy or Extend? . . . . . . . . . . . . . . . . . . . 28
3.4.11. Adapt to ISP constraints . . . . . . . . . . . . . . . 28
3.5. Summary of Homenet Architecture Recommendations . . . . . 29
3.6. Implementing the Architecture on IPv6 . . . . . . . . . . 29
4. References . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.1. Normative References . . . . . . . . . . . . . . . . . . . 29
4.2. Informative References . . . . . . . . . . . . . . . . . . 30
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 33
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 33
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1. Introduction
This document focuses on evolving networking technology within small
"residential home" networks and the associated challenges. For
example, a trend in home networking is the proliferation of
networking technology in an increasingly broad range of devices and
media. This evolution in scale and diversity sets requirements on
IETF protocols. Some of these requirements relate to the need for
multiple subnets, for example for private and guest networks, the
introduction of IPv6, and the introduction of specialized networks
for home automation and sensors.
While some advanced home networks exist, most operate based on IPv4,
employ solutions that we would like to avoid such as (cascaded)
network address translation (NAT), or require expert assistance to
set up. The assumption of this document is that the homenet is "not
actively managed". The architectural constructs in this document are
focused on the problems to be solved when introducing IPv6 with an
eye towards a better result than what we have today with IPv4, as
well as a better result than if the IETF had not given this specific
guidance.
This architecture document aims to provide the basis and guiding
principles for how standard IPv6 mechanisms and addressing [RFC2460]
[RFC4291] can be employed in home networking, while coexisting with
existing IPv4 mechanisms. In emerging dual-stack home networks it is
vital that introducing IPv6 does not adversely affect IPv4 operation.
Future deployments, or specific subnets within an otherwise dual-
stack home network, may be IPv6-only.
[RFC6204] defines basic requirements for customer edge routers
(CERs). The scope of this text is the homenet, and thus the internal
facing interface described in RFC 6204 as well as other components
within the home network. While the network may be dual-stack or
IPv6-only, the definition of specific transition tools on the CER are
out of scope of this text, as is any advice regarding architecture of
the IPv4 part of the network. We assume that IPv4 network
architecture in home networks is what it is, and can not be affected
by new recommendations.
Discussion in the homenet WG has led to a suggestion that there
should be a baseline homenet "version 1" architecture, based on
protocols and implementations that are as far as possible proven and
robust. A future architecture may incorporate more advanced
elements. Feedback is sought on what if anything do we want to say
about potential homenet versions here.
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1.1. Terminology and Abbreviations
In this section we define terminology and abbreviations used
throughout the text.
o CER: Customer Edge Router. The border router at the edge of the
homenet.
o LLN: Low-power and lossy network.
o NAT: Network Address Translation. Typically referring to Network
Address and Port Translation (NAPT).
o NPTv6: Network Prefix Translation for IPv6 [RFC6296].
o PCP: Port Control Protocol [I-D.ietf-pcp-base].
o ULA: Unique Local Addresses [RFC4193].
o uPnP: Universal Plug and Play.
o VM: Virtual machine.
2. Effects of IPv6 on Home Networking
Service providers are deploying IPv6, content is becoming available
on IPv6, and support for IPv6 is increasingly available in devices
and software used in the home. While IPv6 resembles IPv4 in many
ways, it changes address allocation principles, makes multi-
addressing the norm, and allows direct IP addressability and routing
to devices in the home from the Internet. This section presents an
overview of some of the key areas impacted by the introduction of
IPv6 into the home network that are both promising and problematic.
2.1. Multiple subnets and routers
Simple layer 3 topologies involving as few subnets as possible are
preferred in home networks for a variety of reasons including simpler
management and service discovery. However, the incorporation of
dedicated (routed) subnets remains necessary for a variety of
reasons.
For instance, a common feature in modern home routers is the ability
to support both guest and private network subnets. Also, link layer
networking technology is poised to become more heterogeneous, as
networks begin to employ both traditional Ethernet technology and
link layers designed for low-power and lossy networks (LLNs) such as
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those used for certain types of sensor devices. Similar needs for
subnetting may occur in other cases, such as separating building
control or corporate extensions from the Internet access network.
Also, different subnets may be associated with parts of the homenet
that have different routing and security policies.
Documents that provide some more specific background and depth on
this topic include: [I-D.herbst-v6ops-cpeenhancements],
[I-D.baker-fun-multi-router], and [I-D.baker-fun-routing-class].
In addition to routing, rather than NATing, between subnets, there
are issues of when and how to extend mechanisms such as service
discovery which currently rely on link-local addressing to limit
scope.
The presence of a multiple subnet, multi-router network implies that
there is some kind of automatic routing mechanism in place. In
advanced configurations similar to those used in multihomed corporate
networks, there may also be a need to discover border router(s) by an
appropriate mechanism.
2.2. Multi-Addressing of devices
In an IPv6 network, devices may acquire multiple addresses, typically
at least a link-local address and a globally unique address. Thus it
should be considered the norm for devices on IPv6 home networks to be
multi-addressed, and to also have an IPv4 address where the network
is dual-stack. Default address selection mechanisms
[I-D.ietf-6man-rfc3484-revise] allow a node to select appropriate
src/dst address pairs for communications, though such selection may
face problems in the event of multihoming, where nodes will be
configured with one address from each upstream ISP prefix, and the
presence of upstream ingress filtering thus requires multi-addressed
nodes to select the right source address to be used for the
corresponding uplink.
2.3. Unique Local Addresses (ULAs)
[RFC4193] defines Unique Local Addresses (ULAs) for IPv6 that may be
used to address devices within the scope of a single site. Support
for ULAs for IPv6 CERs is described in [RFC6204]. A home network
running IPv6 may deploy ULAs for communication between devices within
the network. ULAs have the potential to be used for stable
addressing in a home network where the externally allocated global
prefix changes over time (either due to renumbering within the
subscriber's ISP or a change of ISP) or where external connectivity
is temporarily unavailable. However, it is undesirable to
aggressively deprecate global prefixes for temporary loss of
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connectivity, so for this to matter there would have to be a
connection breakage longer than the lease period, and even then,
deprecating prefixes when there is no connectivity may not be
advisable. However, while setting a network up there may be a period
with no connectivity.
Another possible reason for using ULAs would be to provide an
indication to applications that the traffic is local. This could
then be used with security settings to designate where a particular
application is allowed to connect to.
ULA addresses will allow constrained LLN devices to create permanent
relations between IPv6 addresses, e.g. from a wall controller to a
lamp. Symbolic host names would require additional non-volatile
memory. Updating global prefixes in sleeping LLN devices might also
be problematic.
Address selection mechanisms should ensure a ULA source address is
used to communicate with ULA destination addresses. The use of ULAs
does not imply use of host-based IPv6 NAT, or NPTv6 prefix-based NAT
[RFC6296], rather that external communications should use a node's
global IPv6 source address.
2.4. Security, Borders, and the elimination of NAT
Current IPv4 home networks typically receive a single global IPv4
address from their ISP and use NAT with private [RFC1918] addresses
for devices within the network. An IPv6 home network removes the
need to use NAT given the ISP offers a sufficiently large IPv6 prefix
to the homenet, allowing every device on every link to be assigned a
globally unique IPv6 address.
The end-to-end communication that is potentially enabled with IPv6 is
both an incredible opportunity for innovation and simpler network
operation, but it is also a concern as it exposes nodes in the
internal networks to receipt of otherwise unwanted traffic from the
Internet.
In IPv4 NAT networks, the NAT provides an implicit firewall function.
[RFC4864] suggests that IPv6 networks with global addresses utilise
"Simple Security" in border firewalls to restrict incoming
connections through a default deny policy. Applications or hosts
wanting to accept inbound connections then need to signal that desire
through a protocol such as uPNP or PCP [I-D.ietf-pcp-base]. In
networks with multiple CERs, PCP will need to handle the cases of
flows that may use one or both exit routers.
Such an approach would reduce the efficacy of end-to-end connectivity
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that IPv6 has the potential to restore, since the need for IPv4 NAT
traversal is replaced by a need to use a signalling protocol to
request a firewall hole be opened. [RFC6092] provides
recommendations for an IPv6 firewall that applies "limitations on
end-to-end transparency where security considerations are deemed
important to promote local and Internet security." The firewall
operation is "simple" in that there is an assumption that traffic
which is to be blocked by default is defined in the RFC and not
expected to be updated by the user or otherwise. The RFC does
however state that CERs should have an option to be put into a
"transparent mode" of operation.
It is important to distinguish between addressability and
reachability; i.e. while IPv6 offers global addressability through
use of globally unique addresses in the home, whether they are
globally reachable or not would depend on firewall or filtering
configuration, and not the presence or use of NAT.
Advanced Security for IPv6 CPEs [I-D.vyncke-advanced-ipv6-security]
takes the approach that in order to provide the greatest end-to-end
transparency as well as security, security policies must be updated
by a trusted party which can provide intrusion signatures and other
"active" information on security threats. This is much like a virus-
scanning tool which must receive updates in order to detect and/or
neutralize the latest attacks as they arrive. As the name implies
"advanced" security requires significantly more resources and
infrastructure (including a source for attack signatures) in
comparison to "simple" security.
In addition to establishing the security mechanisms themselves, it is
important to know where to enable them. If there is some indication
as to which router is connected to the "outside" of the home network,
this is feasible. Otherwise, it can be difficult to know which
security policies to apply where. Further, security policies may be
different for various address ranges if ULA addressing is setup to
only operate within the homenet itself and not be routed to the
Internet at large. Finally, such policies must be able to be applied
by typical home users, e.g. to give a visitor in a "guest" network
access to media services in the home.
It may be useful to classify the border of the home network as a
unique logical interface separating the home network from service
provider network/s. This border interface may be a single physical
interface to a single service provider, multiple layer 2 sub-
interfaces to a single service provider, or multiple connections to a
single or multiple providers. This border is useful for describing
edge operations and interface requirements across multiple functional
areas including security, routing, service discovery, and router
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discovery.
2.5. Naming, and manual configuration of IP addresses
In IPv4, a single subnet NATed home network environment is currently
the norm. As a result, it is for example common practice for users
to be able to connect to a router for configuration via a literal
address such as 192.168.1.1 or some other commonly used RFC 1918
address. In IPv6, while ULAs exist and could potentially be used to
address internally-reachable services, little deployment experience
exists to date. Given a true ULA prefix is effectively a random 48-
bit prefix, it is not reasonable to expect users to manually enter
such address literals for configuration or other purposes. As such,
even for the simplest of functions, naming and the associated
discovery of services is imperative for easy administration of the
homenet.
In a multi-subnet homenet, naming and service discovery should be
expected to operate across the scope of the entire home network, and
thus be able to cross subnet boundaries. It should be noted that in
IPv4, such services do not generally function across home router NAT
boundaries, so this is one area where there is scope for an
improvement in IPv6.
3. Architecture
An architecture outlines how to construct home networks involving
multiple routers and subnets. In this section, we present a set of
typical home network topology models/scenarios, followed by a list of
topics that may influence the architecture discussions, and a set of
architectural principles that govern how the various nodes should
work together. Finally, some guidelines are given for realizing the
architecture with the IPv6 addressing, prefix delegation, global and
ULA addresses, source address selection rules and other existing
components of the IPv6 architecture. The architecture also drives
what protocol extensions are necessary, as will be discussed in
Section 3.6.
3.1. Network Models
In this section we list six network models.
A) Single ISP, Single CER, Single subnet
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B) Single ISP, Single CER, Multiple subnets
C) Single ISP, Single CER, Multiple internal routers
D) Two ISPs, Two CERs, Shared subnets with multiple internal routers
E) Two ISPs, One CER, Isolated subnets with multiple internal
routers
F) Two ISPs, One CER, Shared subnets with multiple internal routers
The models are presented to frame the discussion as to which models
are in scope for the homenet architecture, and which multi-homing
requirements should be met in the architecture.
3.1.1. A: Single ISP, Single CER, Single subnet
Figure 1 shows the simplest possible home network topology, involving
just one router, a local area network, and a set of hosts. Setting
up such networks is in principle well understood today [RFC6204].
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+-------+-------+ \
| Service | \
| Provider | | Service
| Router | | Provider
+-------+-------+ | network
| /
| Customer /
demarc #1 --> | Internet connection /
|
+------+--------+ \
| IPv6 | \
| Customer Edge | \
| Router | /
+------+--------+ /
| |
demarc #2 --> | | End-User
| Local network | network(s)
---+-----+-------+--- \
| | \
+----+-----+ +-----+----+ \
|IPv6 Host | |IPv6 Host | /
| | | | /
+----------+ +-----+----+ /
Figure 1
Two possible demarcation points are illustrated in Figure 1, which
indicate which party is responsible for configuration or
autoconfiguration. Demarcation #1 makes the Customer Edge Router the
responsibility of the customer. This is only practical if the
Customer Edge Router can function with factory defaults installed.
The Customer Edge Router may be pre-configured by the ISP, or by the
home user by some suitably simple method. Demarcation #2 makes the
Customer Edge Router the responsibility of the provider. Both models
of operation must be supported in the homenet architecture, including
the scenarios below with multiple ISPs and demarcation points.
3.1.2. B: Single ISP, Single CER, Multiple subnets
Figure 2 shows another network that now introduces multiple local
area networks. These may be needed for reasons relating to different
link layer technologies in use or for policy reasons. A common
arrangement is to have different link types supported on the same
router, bridged together. This example however presents two subnets.
This could be classic Ethernet in the one subnet and a LLN link layer
technology in the other subnet.
This topology is also relatively well understood today [RFC6204],
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though it certainly presents additional demands with regards to
suitable firewall policies and limits the operation of certain
applications and discovery mechanisms (which may typically today only
succeed within a single subnet).
+-------+-------+ \
| 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 2
3.1.3. C: Single ISP, Single CER, Multiple internal subnets
Figure 3 shows a little bit more complex network with two routers and
eight devices connected to one ISP. This network is similar to the
one discussed in [I-D.ietf-v6ops-ipv6-cpe-router-bis]. The main
complication in this topology compared to the ones described earlier
is that there is no longer a single router that a priori understands
the entire topology. The topology itself may also be complex. It
may not be possible to assume a pure tree form, for instance. This
is a valid consideration as home users may plug routers together to
form arbitrary topologies including loops. In the following sections
we discuss support for arbitrary topologies.
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+-------+-------+ \
| Service | \
| Provider | | Service
| Router | | Provider
+-------+-------+ | network
| /
| Customer /
| Internet connection
|
+------+--------+ \
| IPv6 | \
| Customer Edge | \
| Router | |
+----+-+---+----+ |
Network A | | | Network B/E |
----+-------------+----+ | +---+-------------+------+ |
| | | | | | | |
+----+-----+ +-----+----+ | +----+-----+ +-----+----+ | |
|IPv6 Host | |IPv6 Host | | | IPv6 Host| |IPv6 Host | | |
| | | | | | | | | | |
+----------+ +----------+ | +----------+ +----------+ | |
| | | | |
| ---+------+------+-----+ |
| | Network B/E |
+------+--------+ | | End-User
| IPv6 | | | networks
| Interior +------+ |
| Router | |
+---+-------+-+-+ |
Network C | | Network D |
----+-------------+---+- --+---+-------------+--- |
| | | | |
+----+-----+ +-----+----+ +----+-----+ +-----+----+ |
|IPv6 Host | |IPv6 Host | | IPv6 Host| |IPv6 Host | |
| | | | | | | | /
+----------+ +----------+ +----------+ +----------+ /
Figure 3
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3.1.4. D: Two ISPs, Two CERs, Shared subnets with multiple internal
routers
+-------+-------+ +-------+-------+ \
| Service | | Service | \
| Provider A | | Provider B | | Service
| Router | | Router | | Provider
+------+--------+ +-------+-------+ | network
| | /
| Customer | /
| Internet connections | /
| |
+------+--------+ +-------+-------+ \
| IPv6 | | IPv6 | \
| Customer Edge | | Customer Edge | \
| Router 1 | | Router 2 | /
+------+--------+ +-------+-------+ /
| | /
| | | End-User
---+---------+---+---------------+--+----------+--- | network(s)
| | | | \
+----+-----+ +-----+----+ +----+-----+ +-----+----+ \
|IPv6 Host | |IPv6 Host | | IPv6 Host| |IPv6 Host | /
| | | | | | | | /
+----------+ +----------+ +----------+ +----------+
Figure 4
Figure 4 illustrates a multihomed home network model, where the
customer has connectivity via CER1 to ISP A and via CER2 to ISP B.
This example shows one shared subnet where IPv6 nodes would
potentially be multihomed and receive multiple IPv6 global addresses,
one per ISP. This model may also be combined with that shown in
Figure 3 to create a more complex scenario with subnets that my be
behind multiple internal routers.
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3.1.5. E: Two ISPs, One CER, Isolated subnets with multiple internal
routers
+-------+-------+ +-------+-------+ \
| Service | | Service | \
| Provider A | | Provider B | | Service
| Router | | Router | | Provider
+-------+-------+ +-------+-------+ | network
| | /
| Customer | /
| Internet | /
| connections | |
+---------+---------+ \
| IPv6 | \
| Customer Edge | \
| Router 1 | /
+---------+---------+ /
| | /
| | | End-User
---+---------+---+-- --+--+----------+--- | network(s)
| | | | \
+----+-----+ +-----+----+ +----+-----+ +-----+----+ \
|IPv6 Host | |IPv6 Host | | IPv6 Host| |IPv6 Host | /
| | | | | | | | /
+----------+ +----------+ +----------+ +----------+
Figure 5
Figure 5 illustrates a model where a home network may have multiple
connections to multiple providers or multiple logical connections to
the same provider, but the associated subnet(s) are isolated. Some
deployment scenarios may require this model.
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3.1.6. F: Two ISPs, One CER, Shared subnets with multiple internal
routers
+-------+-------+ +-------+-------+ \
| Service | | Service | \
| Provider A | | Provider B | | Service
| Router | | Router | | Provider
+-------+-------+ +-------+-------+ | network
| | /
| Customer | /
| Internet | /
| connections | |
+---------+---------+ \
| IPv6 | \
| Customer Edge | \
| Router 1 | /
+---------+---------+ /
| | /
| | | End-User
---+------------+-+------------+-+-------------+--- | network(s)
| | | | \
+----+-----+ +----+-----+ +----+-----+ +-----+----+ \
|IPv6 Host | |IPv6 Host | | IPv6 Host| |IPv6 Host | /
| | | | | | | | /
+----------+ +----------+ +----------+ +----------+
Figure 6
Figure 6 illustrates a model where a home network may have multiple
connections to multiple providers or multiple logical connections to
the same provider, with shared internal subnets, that may be multiple
layers deep.
3.2. Determining the Requirements
[RFC6204] defines "basic" requirements for IPv6 Customer Edge
Routers, while [I-D.ietf-v6ops-ipv6-cpe-router-bis] describes
"advanced" features. In general, home network equipment needs to
cope with the different types of network topologies discussed above.
Manual configuration is rarely, if at all, possible, given the
knowledge level of typical home users. The equipment needs to be
prepared to handle at least
o Prefix configuration for routers
o Managing routing
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o Name resolution
o Service discovery
o Network security
The remainder of the architecture document is presented as
considerations and principles that lead to more specific requirements
for the five general areas listed above.
3.3. Considerations
This section lists some considerations for home networking that may
affect the architecture and associated requirements.
3.3.1. Multihoming
A homenet may be multihomed to multiple providers. This may either
take a form where there are multiple isolated networks within the
home (see Network Model E above) or a more integrated network where
the connectivity selection is dynamic (see Network Model D or F
above). Current practice is typically of the former kind, but the
latter is expected to become more commonplace.
There are some specific multihoming considerations for homenet
scenarios. First, it may be the case that multihoming applies due to
an ISP migration from a transition method to a native deployment,
e.g. a 6rd [RFC5969] sunset scenario. Second, one upstream may be a
"walled garden", and thus only appropriate to be used for
connectivity to the services of that provider.
In an integrated network, specific appliances or applications may use
their own external connectivity, or the entire network may change its
connectivity based on the status of the different upstream
connections. The complexity of the multihoming solution required
will depend on the Network Model deployed. For example, Network
Models E and F have a single CER and thus could perform source
routing at the single network exit point.
The general approach for IPv6 multihoming is for a hosts to receive
multiple addresses from multiple providers, and to select the
appropriate source address to communicate via a given provider. An
alternative is to deploy ULAs with a site and then use NPTv6
[RFC6296], a prefix translation-based mechanism, at the edge. This
obviously comes at some architectural cost, which is why approaches
such as [I-D.v6ops-multihoming-without-ipv6nat] have been suggested.
There has been much work on multihoming in the IETF, without (yet)
widespread deployment of proposed solutions. Host-based methods such
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as Shim6 [RFC5533] have also been defined, but of course require
support in the hosts.
If multihoming is supported additional requirements apply. The
general multihoming problem is broad, and solutions may include
complex architectures for monitoring connectivity, traffic
engineering, identifier-locator separation, connection survivability
across multihoming events, and so on. This implies that if there is
any support for multihoming defined in the homenet architecture it
should be limited to a very small subset of the overall problem.
The current set of assumptions and requirements proposed by the
homenet architecture team is:
MH1) The homenet WG should not try to make another attempt at
solving complex multihoming; we should prefer to support
scenarios for which solutions exist today.
MH2) Single CER Network Models E and F are in scope, and may be
solved by source routing at the CER.
MH3) It is desirable to avoid deployment of NPTv6 at the CER. Hosts
should be multi-addressed from each ISP they may communicate
with or through.
MH4) Solutions that involve host changes should be avoided.
MH5) Walled garden multihoming is in scope.
MH6) Transition method sunsetting is in scope. The topic of
multihoming with specific (6rd) transition coexistence is
discussed in [I-D.townsley-troan-ipv6-ce-transitioning].
MH7) "Just" picking the right source address to use to fall foul of
ingress filtering on upstream ISP connections (as per Network
Model D) is not a trivial task. A solution is highly
desirable, but out of scope of homenet.
MH8) Source routing throughout the homenet, a la
[I-D.baker-fun-multi-router], requires relatively significant
routing changes. The network should "guarantee" routing the
packet to the correct exit given the source address, but hosts
are responsible for anything extra, e.g. detecting failure, or
choosing a new src/dst address combination.
Feedback is sought on the above points.
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3.3.2. Quality of Service in multi-service home networks
Support for QoS in a multi-service homenet may be a requirement, e.g.
for a critical system (perhaps healthcare related), or for
differentiation between different types of traffic (file sharing,
cloud storage, live streaming, VoIP, etc). Different media types may
have different QoS properties or capabilities.
However, homenet scenarios should require no new QoS protocols. A
DiffServ [RFC2475] approach with a small number of predefined traffic
classes should generally be sufficient, though at present there is
little experience of QoS deployment in home networks.
There may also be complementary mechanisms that could be beneficial
in the homenet domain, such as ensuring proper buffering algorithms
are used as described in [Gettys11].
3.3.3. Privacy considerations
There are no specific privacy concerns for this text. It should be
noted that many ISPs are expected to offer relatively stable IPv6
prefixes to customers, and thus the network prefix associated with
the host addresses they use would not generally change over a
reasonable period of time, e.g. between restructuring of an ISPs
residential network provision.
3.4. Principles
There is little that the Internet standards community can do about
the physical topologies or the need for some networks to be separated
at the network layer for policy or link layer compatibility reasons.
However, there is a lot of flexibility in using IP addressing and
inter-networking mechanisms. In this section we discuss how this
flexibility should be used to provide the best user experience and
ensure that the network can evolve with new applications in the
future.
The following principles should be followed when designing homenet
solutions. Where requirements are associated with those principles,
they are listed here. There is no implied priority by the order in
which the principles themselves are listed.
3.4.1. Reuse existing protocols
It is desirable to reuse existing protocols where possible, but at
the same time to avoid consciously precluding the introduction of new
or emerging protocols.
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A generally conservative approach, giving weight to running code, is
preferable. Where new protocols are required, evidence of commitment
to implementation by appropriate vendors or development communities
is highly desirable. Protocols used should be backwardly compatible.
Where possible, changes to hosts should be minimised. Some changes
may be unavoidable however, e.g. signalling protocols to punch holes
in firewalls where "Simple Security" is deployed in a CER.
Changes to routers should also be minimised, e.g.
[I-D.baker-fun-routing-class] suggests introducing a routing protocol
that may route on both source and destination addresses, which would
be a significant change compared to current practices.
Liaisons with other appropriate standards groups and related
organisations is desirable, e.g. the IEEE and Wi-Fi Alliance.
3.4.2. Dual-stack Operation
The homenet architecture targets both IPv6-only and dual-stack
networks. While the CER requirements in RFC 6204 are aimed at IPv6-
only networks, it is likely that dual-stack homenets will be the norm
for some period of time. IPv6-only networking may first be deployed
in home networks in "greenfield" scenarios, or perhaps as one element
of an otherwise dual-stack network. The homenet architecture must
operate in the absence of IPv4, and IPv6 must work in the same
scenarios as IPv4 today.
Running IPv6-only may require documentation of additional
considerations such as:
Ensuring there is a way to access content in the IPv4 Internet.
This can be arranged through incorporating NAT64 [RFC6144]
functionality in the home gateway router, for instance.
DNS discovery mechanisms are enabled for IPv6. Both stateless
DHCPv6 [RFC3736] [RFC3646] and Router Advertisement options
[RFC6106] may have to be supported and turned on by default to
ensure maximum compatibility with all types of hosts in the
network. This requires, however, that a working DNS server is
known and addressable via IPv6.
All nodes in the home network support operations in IPv6-only
mode. Some current devices work well with dual-stack but fail to
recognize connectivity when IPv4 DHCP fails, for instance.
In dual-stack networks, solutions for IPv6 must not adversely affect
IPv4 operation. It is likely that topologies of IPv4 and IPv6
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networks would be as congruent as possible.
Note that specific transition tools, particularly those running on
the border CER to support transition tools being used inside the
homenet, are out of scope. Use of tools, such as 6rd, on the border
CER to support ISP access network transition are to be expected, but
not within scope of homenet, which focuses on the internal
networking.
3.4.3. Largest Possible Subnets
Today's IPv4 home networks generally have a single subnet, and early
dual-stack deployments have a single congruent IPv6 subnet, possibly
with some bridging functionality.
Future home networks are highly likely to need multiple subnets, for
the reasons described earlier. As part of the self-organisation of
the network, the network should subdivide itself to the largest
possible subnets that can be constructed within the constraints of
link layer mechanisms, bridging, physical connectivity, and policy.
For instance, separate subnetworks are necessary where two different
link layers cannot be bridged, or when a policy requires the
separation of a private and visitor parts of the network.
While it may be desirable to maximise the chance of link-local
protocols operating across a homenet by maximising the size of a
subnet across the homenet, multiple subnet home networks are
inevitable, so their support must be included. A general
recommendation is to follow the same topology for IPv6 as is used for
IPv4, but not to use NAT. Thus there should be routed IPv6 where an
IPv4 NAT is used, and where there is no NAT there should be bridging
if the link layer allows this.
In some cases IPv4 NAT home networks may feature cascaded NATs, e.g.
where NAT routers are included within VMs or Internet connection
services are used. IPv6 routed versions of such tools will be
required.
3.4.4. Transparent End-to-End Communications
An IPv6-based home network architecture should naturally offer a
transparent end-to-end communications model. Each device should be
addressable by a unique address. Security perimeters can of course
restrict the end-to-end communications, but it is simpler given the
availability of globally unique addresses to block certain nodes from
communicating by use of an appropriate filtering device than to
configure the address translation device to enable appropriate
address/port forwarding in the presence of a NAT.
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As discussed previously, it is important to note the difference
between hosts being addressable and reachable. Thus filtering is to
be expected, while host-based IPv6 NAT is not. End-to-end
communications are important for their robustness against failure of
intermediate systems, where in contrast NAT is dependent on state
machines which are not self-healing.
When configuring filters, protocols for securely associating devices
are desirable. In the presence of "Simple Security" the use of
signalling protocols such as uPnP or PCP may be expected to punch
holes in the firewall (and be able to handle cases where there are
multiple CERs/firewall(s). Alternatively, RFC 6092 supports the
option for a border CER to run in "transparent mode", in which case a
protocol like PCP is not required, but the security model is more
open.
3.4.5. IP Connectivity between All Nodes
A logical consequence of the end-to-end communications model is that
the network should by default attempt to provide IP-layer
connectivity between all internal parts as well as between the
internal parts and the Internet. This connectivity should be
established at the link layer, if possible, and using routing at the
IP layer otherwise.
Local addressing (ULAs) may be used within the scope of a home
network. It would be expected that ULAs may be used alongside one or
more globally unique ISP-provided addresses/prefixes in a homenet.
ULAs may be used for all devices, not just those intended to have
internal connectivity only. ULAs may then be used for stable
internal communications should the ISP-provided prefix (suddenly)
change, or external connectivity be temporarily lost. The use of
ULAs should be restricted to the homenet scope through filtering at
the border(s) of the homenet; thus "end-to-end" for ULAs is limited
to the homenet.
In some cases full internal connectivity may not be desirable, e.g.
in certain utility networking scenarios, or where filtering is
required for policy reasons against guest network subnet(s). Note
that certain scenarios may require co-existence of ISP connectivity
providing a general Internet service with provider connectivity to a
private "walled garden" network.
Some home networking scenarios/models may involve isolated subnet(s)
with their own CERs. In such cases connectivity would only be
expected within each isolated network (though traffic may potentially
pass between them via external providers).
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LLNs provide an example of where there may be secure perimeters
inside the homenet. Constrained LLN nodes may implement WPA-style
network key security but may depend on access policies enforced by
the LLN border router.
3.4.6. Routing functionality
Routing functionality is required when there are multiple routers in
use. This functionality could be as simple as the current "default
route is up" model of IPv4 NAT, or it could involve running an
appropriate routing protocol.
The homenet routing environment may include traditional IP networking
where existing link-state or distance-vector protocols may be used,
but also new LLN or other "constrained" networks where other
protocols may be more appropriate. IPv6 VM solutions may also add
additional routing requirements. Current home deployments use
largely different mechanisms in sensor and basic Internet
connectivity networks.
In this section we list the requirements and assumptions for routing
functionality within the homenet environment.
RT1) The protocol should preferably be an existing deployed
protocol that has been proven to be reliable and robust.
RT2) It is preferable that the protocol is "lightweight".
RT3) The protocol should provide reachability between all nodes in
the homement.
RT4) In general, LLN or other networks should be able to attach and
participate the same way or map/be gatewayed to the main
homenet.
RT5) Multiple interface PHYs must be accounted for in the homenet
routed topology. Technologies such as Ethernet, WiFi, MoCA,
etc must be capable of coexisting in the same environment and
should be tested as part of any routed deployment. The
inclusion of the PHY layer characteristics including
bandwidth, loss, and latency in path computation should be
considered for optimizing communication in the homenet.
RT6) Minimizing convergence time should be a goal in any routed
environment, but as a guideline a maximum convergence time of
a couple of minutes should be the target.
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RT7) It is desirable that the routing protocol has knowledge of the
homenet topology, which implies a link-state protocol may be
preferable. If so, it is also desirable that the
announcements and use of LSAs and RAs are appropriately
coordinated.
RT8) Any routed solution will require a means for determining the
boundaries of the homenet. Borders may include but are not
limited to the interface to the upstream ISP, a gateway device
to a separate home network such as a SmartGrid or similar LLN
network, and in some cases there may be no border such as
before an upstream connection has been established. Devices
in the homenet must be able to find the path to the Internet
as well as other devices on the home intranet. The border
discovery functionality may be integrated into the routing
protocol itself, but may also be imported via a separate
discovery mechanism.
RT9) The routing environment should be self-configuring, as
discussed in the next subsection. An example of how OSPFv3
can be self-configuring in a homenet is described in
[I-D.acee-ospf-ospfv3-autoconfig]. The exception is
configuration of a "secret" for authentication methods. It is
important that self-configuration with "unintended" devices is
avoided.
RT10) The protocol should not require upstream ISP connectivity to
be established to continue routing within the homenet.
RT11) Multiple upstreams should be supported, as described in the
Network Models earlier.
RT12) To support multihoming within a homenet, a routing protocol
that can make routing decisions based on source and
destination addresses is desirable, to avoid upstream ISP
ingress filtering problems. In general the routing protocol
should support multiple ISP uplinks and delegated prefixes in
concurrent use.
RT13) The routing system should support walled garden environments.
RT14) Load-balancing to multiple providers is not a requirement, but
failover from a primary to a backup link when available must
be a requirement.
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RT15) It is assumed that the typical router designed for residential
use does not contain the memory or cpu required to process a
full Internet routing table this should not be a requirement
for any homenet device.
A new I-D has been published on homenet routing requirements, see
[I-D.howard-homenet-routing-comparison] and evaluations of common
routing protocols made against those requirements, see
[I-D.howard-homenet-routing-requirements]. The requirements from the
former document have been worked into this architecture text.
Feedback is sought on how these documents move forward.
3.4.7. Self-Organising
A home network architecture should be naturally self-organising and
self-configuring under different circumstances relating to the
connectivity status to the Internet, number of devices, and physical
topology. While the homenet should be self-organising, it should be
possible to manually adjust (override) the current configuration.
The most important function in this respect is prefix delegation and
management. The requirements and assumptions for the prefix
delegation function are summarised as follows:
PD1) From the homenet perspective, a single prefix should be
received on the border CER [RFC3633]. The ISP should only see
that aggregate, and not single /64 prefixes allocated within
the homenet.
PD2) Each link in the homenet should receive a prefix from within
the ISP-provided prefix.
PD3) Delegation should be autonomous, and not assume a flat or
hierarchical model.
PD4) The assignment mechanism should provide reasonable efficiency,
so that typical home network prefix allocation sizes can
accommodate all the necessary /64 allocations in most cases.
A currently typical /60 allocation gives 16 /64 subnets.
PD5) Duplicate assignment of multiple /64s to the same network
should be avoided.
PD6) The network should behave as gracefully as possible in the
event of prefix exhaustion.
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PD7) Where multiple CERs exist with multiple ISP prefix pools, it
is expected that routers within the homenet would assign
themselves prefixes from each ISP they communicate with/
through.
PD8) Where ULAs are used, most likely but not necessarily in
parallel with global prefixes, one router will need to be
elected as the generator of ULA prefixes for the homenet.
PD9) Delegation within the homenet should give each link a prefix
that is persistent across reboots, power outages and similar
short-term outages.
PD10) Addition of a new routing device should not affect existing
persistent prefixes, but persistence may not be expected in
the face of significant "replumbing" of the homenet.
PD11) Persistence should not depend on router boot order.
PD12) Persistent prefixes may imply the need for stable storage on
routing devices, and also a method for a home user to "reset"
the stored prefix should a significant reconfiguration be
required (though ideally the home user should not be involved
at all).
PD13) The delegation method should support "flash" renumbering.
Several proposals have been made for prefix delegation within a
homenet. One group of proposals is based on DHCPv6 PD, as described
in [I-D.baker-homenet-prefix-assignment],
[I-D.chakrabarti-homenet-prefix-alloc], [RFC3315] and [RFC3633]. The
other uses OSPFv3, as described in
[I-D.arkko-homenet-prefix-assignment]. More detailed analysis of
these approaches needs to be made against the requirements/
assumptions listed above.
Other parameters of the network will need to be self-organising. The
network elements will need to be integrated in a way that takes
account of the various lifetimes on timers that are used on those
different elements, e.g. DHCPv6 PD, router, valid prefix and
preferred prefix timers.
The homenet will have one or more borders, with external connectivity
providers and potentially parts of the internal network (e.g. for
policy-based reasons). It should be possible to automatically
perform border discovery at least for the ISP borders. Such borders
determine for example the scope of ULAs, site scope multicast
boundaries and where firewall policies may be applied.
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The network cannot be expected to be completely self-organising, e.g.
some security parameters are likely to need manual configuration,
e.g. WPA2 configuration for wireless access control. Some existing
mechanisms exist to assist home users to associate devices as simply
as possible, e.g. "connect" button support.
3.4.8. Fewest Topology Assumptions
There should ideally be no built-in assumptions about the topology in
home networks, as users are capable of connecting their devices in
ingenious ways. Thus arbitrary topologies will need to be supported.
It is important not to introduce new IPv6 scenarios that would break
with IPv4+NAT, given that dual-stack homenets will be commonplace for
some time. There may be IPv6-only topologies that work where IPv4 is
not used or required.
3.4.9. Naming and Service Discovery
The most natural way to think about naming and service discovery
within a homenet is to enable it to work across the entire residence,
disregarding technical borders such as subnets but respecting policy
borders such as those between visitor and internal networks.
Homenet naming systems will be required that work internally or
externally, though the domains used may be different from those
different perspectives.
A desirable target may be a fully functional self-configuring secure
local DNS service so that all devices are referred to by name, and
these FQDNs are resolved locally. This would make clean use of ULAs
and multiple ISP-provided prefixes much easier. The local DNS
service should be (by default) authoritative for the local name space
in both IPv4 and IPv6. A dual-stack residential gateway should
include a dual-stack DNS server.
Consideration will also need to be given for existing protocols that
may be used within a network, e.g. mDNS, and how these interact with
unicast-based DNS services.
With the introduction of new top level domains, there is potential
for ambiguity between for example a local host called apple and (if
it is registered) an apple gTLD, so some local name space is probably
required, which should also be configurable to something else by a
home user, e.g. ".home", if desired.
It is also important to note here that there is also potential
ambiguity if a mobile device should move between two local name
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spaces called ".home", for example.
For service discovery, support may be required for IPv6 multicast
across the scope of the home network, and thus at least all routing
devices in the network.
3.4.10. Proxy or Extend?
Related to the above, we believe that general existing discovery
protocols that are designed to only work within a subnet should be
modified/extended to work across subnets, rather than defining proxy
capabilities for each of those functions.
Feedback is desirable on which other functions/protocols assume
subnet-only operation, in the context of existing home networks.
Some experience from enterprises may be relevant here.
3.4.11. Adapt to ISP constraints
The home network may receive an arbitrary length IPv6 prefix from its
provider, e.g. /60 or /56. The offered prefix may be stable over
time or change frequently. The home network needs to be adaptable to
such ISP policies, e.g. on constraints placed by the size of prefix
offered by the ISP. The ISP may use [I-D.ietf-dhc-pd-exclude] for
example.
The internal operation of the home network should also not depend on
the availability of the ISP network at any given time, other than for
connectivity to services or systems off the home network. This
implies the use of ULAs as supported in RFC6204. If used, ULA
addresses should be stable so that they can always be used
internally, independent of the link to the ISP.
It is expected that ISPs will deliver a relatively stable home prefix
to customers. The norm for residential customers of large ISPs may
similar to their single IPv4 address provision; by default it is
likely to remain persistent for some time, but changes in the ISP's
own provisioning systems may lead to the customer's IP (and in the
IPv6 case their prefix pool) changing.
When an ISP needs to restructure and in doing so renumber its
customer homenets, "flash" renumbering is likely to be imposed. This
implies a need for the homenet to be able to handle a sudden
renumbering event which, unlike the process described in [RFC4192],
would be without a "flag day". The customer may of course also
choose to move to a new ISP, and thus begin using a new prefix. Thus
it's desirable that homenet protocols or operational processes don't
add unnecessary complexity for renumbering.
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The 6renum WG is studying IPv6 renumbering for enterprise networks.
It is not currently targetting homenets, but may produce outputs that
are relevant.
3.5. Summary of Homenet Architecture Recommendations
Feedback sought on whether a summary section would be useful.
3.6. Implementing the Architecture on IPv6
The necessary mechanisms are largely already part of the IPv6
protocol set and common implementations, though there are some
exceptions. For automatic routing, it is expected that existing
routing protocols can be used as is. However, a new mechanism may be
needed in order to turn a selected protocol on by default. Support
for multiple exit routers and multi-homing would also require
extensions, even if focused on the problem of multi-addressed hosts
selecting the right source address to avoid falling foul of ingress
filtering on upstream ISP connections.
For name resolution and service discovery, extensions to existing
multicast-based name resolution protocols are needed to enable them
to work across subnets, within the scope of the home network.
The hardest problems in developing solutions for home networking IPv6
architectures include discovering the right borders where the domain
"home" ends and the service provider domain begins, deciding whether
some of necessary discovery mechanism extensions should affect only
the network infrastructure or also hosts, and the ability to turn on
routing, prefix delegation and other functions in a backwards
compatible manner.
4. References
4.1. Normative References
[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and
E. Lear, "Address Allocation for Private Internets",
BCP 5, RFC 1918, February 1996.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998.
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated
Services", RFC 2475, December 1998.
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[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.
[RFC4192] Baker, F., Lear, E., and R. Droms, "Procedures for
Renumbering an IPv6 Network without a Flag Day", RFC 4192,
September 2005.
[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast
Addresses", RFC 4193, October 2005.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, February 2006.
[RFC4864] Van de Velde, G., Hain, T., Droms, R., Carpenter, B., and
E. Klein, "Local Network Protection for IPv6", RFC 4864,
May 2007.
[RFC5533] Nordmark, E. and M. Bagnulo, "Shim6: Level 3 Multihoming
Shim Protocol for IPv6", RFC 5533, June 2009.
[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.
[RFC6204] Singh, H., Beebee, W., Donley, C., Stark, B., and O.
Troan, "Basic Requirements for IPv6 Customer Edge
Routers", RFC 6204, April 2011.
[RFC6296] Wasserman, M. and F. Baker, "IPv6-to-IPv6 Network Prefix
Translation", RFC 6296, June 2011.
4.2. Informative References
[RFC3646] Droms, R., "DNS Configuration options for Dynamic Host
Configuration Protocol for IPv6 (DHCPv6)", RFC 3646,
December 2003.
[RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol
Arkko, et al. Expires August 2, 2012 [Page 30]
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(DHCP) Service for IPv6", RFC 3736, April 2004.
[RFC6106] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli,
"IPv6 Router Advertisement Options for DNS Configuration",
RFC 6106, November 2010.
[RFC6144] Baker, F., Li, X., Bao, C., and K. Yin, "Framework for
IPv4/IPv6 Translation", RFC 6144, April 2011.
[I-D.baker-fun-multi-router]
Baker, F., "Exploring the multi-router SOHO network",
draft-baker-fun-multi-router-00 (work in progress),
July 2011.
[I-D.townsley-troan-ipv6-ce-transitioning]
Townsley, M. and O. Troan, "Basic Requirements for
Customer Edge Routers - multihoming and transition",
draft-townsley-troan-ipv6-ce-transitioning-02 (work in
progress), December 2011.
[I-D.baker-fun-routing-class]
Baker, F., "Routing a Traffic Class",
draft-baker-fun-routing-class-00 (work in progress),
July 2011.
[I-D.howard-homenet-routing-comparison]
Howard, L., "Evaluation of Proposed Homenet Routing
Solutions", draft-howard-homenet-routing-comparison-00
(work in progress), December 2011.
[I-D.howard-homenet-routing-requirements]
Howard, L., "Homenet Routing Requirements",
draft-howard-homenet-routing-requirements-00 (work in
progress), December 2011.
[I-D.herbst-v6ops-cpeenhancements]
Herbst, T. and D. Sturek, "CPE Considerations in IPv6
Deployments", draft-herbst-v6ops-cpeenhancements-00 (work
in progress), October 2010.
[I-D.vyncke-advanced-ipv6-security]
Vyncke, E., Yourtchenko, A., and M. Townsley, "Advanced
Security for IPv6 CPE",
draft-vyncke-advanced-ipv6-security-03 (work in progress),
October 2011.
[I-D.ietf-v6ops-ipv6-cpe-router-bis]
Singh, H., Beebee, W., Donley, C., Stark, B., and O.
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Troan, "Advanced Requirements for IPv6 Customer Edge
Routers", draft-ietf-v6ops-ipv6-cpe-router-bis-01 (work in
progress), July 2011.
[I-D.ietf-6man-rfc3484-revise]
Matsumoto, A., Kato, J., Fujisaki, T., and T. Chown,
"Update to RFC 3484 Default Address Selection for IPv6",
draft-ietf-6man-rfc3484-revise-05 (work in progress),
October 2011.
[I-D.ietf-dhc-pd-exclude]
Korhonen, J., Savolainen, T., Krishnan, S., and O. Troan,
"Prefix Exclude Option for DHCPv6-based Prefix
Delegation", draft-ietf-dhc-pd-exclude-04 (work in
progress), December 2011.
[I-D.v6ops-multihoming-without-ipv6nat]
Troan, O., Miles, D., Matsushima, S., Okimoto, T., and D.
Wing, "IPv6 Multihoming without Network Address
Translation", draft-v6ops-multihoming-without-ipv6nat-00
(work in progress), March 2011.
[I-D.baker-homenet-prefix-assignment]
Baker, F. and R. Droms, "IPv6 Prefix Assignment in Small
Networks", draft-baker-homenet-prefix-assignment-00 (work
in progress), October 2011.
[I-D.arkko-homenet-prefix-assignment]
Arkko, J. and A. Lindem, "Prefix Assignment in a Home
Network", draft-arkko-homenet-prefix-assignment-01 (work
in progress), October 2011.
[I-D.acee-ospf-ospfv3-autoconfig]
Lindem, A. and J. Arkko, "OSPFv3 Auto-Configuration",
draft-acee-ospf-ospfv3-autoconfig-00 (work in progress),
October 2011.
[I-D.ietf-pcp-base]
Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P.
Selkirk, "Port Control Protocol (PCP)",
draft-ietf-pcp-base-22 (work in progress), January 2012.
[I-D.chakrabarti-homenet-prefix-alloc]
Nordmark, E., Chakrabarti, S., Krishnan, S., and W.
Haddad, "Simple Approach to Prefix Distribution in Basic
Home Networks", draft-chakrabarti-homenet-prefix-alloc-01
(work in progress), October 2011.
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[Gettys11]
Gettys, J., "Bufferbloat: Dark Buffers in the Internet",
March 2011,
<http://www.ietf.org/proceedings/80/slides/tsvarea-1.pdf>.
Appendix A. Acknowledgments
The authors would like to thank Brian Carpenter, Mark Andrews, Fred
Baker, Ray Bellis, Cameron Byrne, Stuart Cheshire, Lorenzo Colitti,
Ralph Droms, Lars Eggert, Jim Gettys, Wassim Haddad, Joel M. Halpern,
David Harrington, Lee Howard, Ray Hunter, Joel Jaeggli, Heather
Kirksey, Ted Lemon, Erik Nordmark, Michael Richardson, Barbara Stark,
Sander Steffann, Dave Thaler, JP Vasseur, Curtis Villamizar, Russ
White, and James Woodyatt for their contributions within homenet WG
meetings and the mailing list, and Mark Townsley for being an initial
editor/author of this text before taking his position as homenet WG
co-chair.
Authors' Addresses
Jari Arkko
Ericsson
Jorvas 02420
Finland
Email: jari.arkko@piuha.net
Anders Brandt
Sigma Designs
Emdrupvej 26A, 1
Copenhagen DK-2100
Denmark
Email: abr@sdesigns.dk
Tim Chown
University of Southampton
Highfield
Southampton, Hampshire SO17 1BJ
United Kingdom
Email: tjc@ecs.soton.ac.uk
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Jason Weil
Time Warner Cable
13820 Sunrise Valley Drive
Herndon, VA 20171
USA
Email: jason.weil@twcable.com
Ole Troan
Cisco Systems, Inc.
Drammensveien 145A
Oslo N-0212
Norway
Email: ot@cisco.com
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