V6OPS B. Carpenter
Internet-Draft Univ. of Auckland
Intended status: Informational S. Jiang
Expires: August 6, 2011 Huawei Technologies Co., Ltd
V. Kuarsingh
Rogers Communications
February 2, 2011
Framework for IP Version Transition Scenarios
draft-ietf-v6ops-v4v6tran-framework-01
Abstract
This document sets out a framework for the presentation of scenarios
and recommendations for a variety of approaches to the transition
from IPv4 to IPv6, given the necessity for a long period of co-
existence of the two protocols.
Status of this Memo
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This Internet-Draft will expire on August 6, 2011.
Copyright Notice
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document authors. All rights reserved.
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Document Topics . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5
6. Change log . . . . . . . . . . . . . . . . . . . . . . . . . . 5
7. Informative References . . . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6
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1. Introduction
This document sets out a framework for the presentation of scenarios
and recommendations for a variety of approaches to the transition
from IPv4 to IPv6, given the necessity for a long period of co-
existence of the two protocols. A general "call to arms" for
transition is found in [RFC5211], and a recommendation for four
principal scenarios is given in
[I-D.arkko-ipv6-transition-guidelines]. A report on experience and
plans of various Internet Service Providers (ISPs) is given in
[RFC6036]. However, it is clear that operators require more detailed
technical recommendations than are available so far. Unfortunately,
the number of different combinations of existing IPv4 deployment
models, customer profiles and requirements, and possible coexistence
and transition models, is enormous, so it is quite impracticable to
produce either a set of recommendations for each case, or a
recommended "one size fits all" model. That is why this document
proposes a set of topics or dimensions, as a framework for a
reasonable number of recommendation documents.
The reader is assumed to be familiar with IPv6. The IETF's view of
core IPv6 requirements is to be found in [RFC4294] (currently being
updated as [I-D.ietf-6man-node-req-bis]). However, this does not
give a complete view of mechanisms an ISP may need to deploy, since
it considers the requirements for an individual node, not for a
network or service infrastructure as a whole.
[RFC4029] discussed scenarios for introducing IPv6 into ISP networks,
as the problem was viewed some years ago. Its end goal was simply a
dual-stack ISP backbone. Today's view is that this is insufficient,
as it does not allow for prolonged interworking between IPv6-only and
legacy (IPv4-only) hosts. Indeed, the end goal today might be an
IPv6-only ISP backbone, with some form of legacy IPv4 support
[I-D.arkko-ipv6-transition-guidelines].
Although the basic IPv6 standards are stable, considerable work
continues in several IETF working groups, on issues such as
multihoming, tunneling, and IP layer interworking between IPv6-only
and IPv4-only hosts. However, operators faced with IPv4 address
exhaustion in the coming few years need immediate guidance. These
operators cannot avoid the need for general skills acquisition, or
the need to write their own detailed deployment plan, but they also
need guidance for generic scenarios similar to their actual
situation. They cannot obtain such guidance from individual protocol
specifications developed by the IETF, so there is a need for
additional documents.
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2. Document Topics
On the assumption that a series of documents are produced describing
and recommending transition scenarios, there are two basic
conditions:
1. The documents will not be primary protocol specifications,
because those are the outcome of IETF working groups chartered to
work on specific protocol mechanisms.
2. The documents are addressed to service providers who have taken
the decision to support IPv6, have acquired basic knowledge and
skills, have determined how they will obtain upstream IPv6
connectivity, and are ready to write their operational plan for
transition.
The documents should describe scenarios for real transition to IPv6,
not life extensions to IPv4 or other matters best handled in other
working groups. They should each cover some or all of the following
aspects or dimensions:
o For the convenience of readers, each document should briefly
describe its network model in the Abstract (or Introduction) for
quick reference.
o The documents should explain how certain technology components fit
together in a given transition and co-existence scenario.
o They will present major generic network models, and their subsets,
which exist (or are firmly planned) today, including network
topologies and/or architectures.
o They should specify their scope: the range of technologies that
they do or do not apply to (e.g. specific access network
technologies, core network technologies and topologies, mobile vs
fixed hosts, business vs private customers, etc.).
o They should develop analysis criteria on how to recognize
appropriate transition technologies for existing provider networks
within their scope. This should include information related to
deployed protocols and functions which may assist or hinder
various transition technologies from being deployed.
o If multiple transition technologies are needed for provider
environments where access networks differ and have various
capabilities, the documents should show how these technologies can
be deployed simultaneously.
o They should describe how multiple technologies can co-exist, if
necessary, during all stages of migration (e.g., moving from IPv4
Only to Dual-Stack to DS-Lite to NAT64).
o They should cover considerations for legacy operation while moving
to IPv6 and its transition technologies. Many operators will have
large quantities of IPv4-only equipment which cannot feasibly be
upgraded until the end of its economic life, or which is under
customer control.
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o They should cover considerations which apply when retro-fitting
various technologies to existing networks. Included in this would
be impacts on ancillary protocols, routing platforms/systems,
security policies, provisioning systems, network services (i.e.
DHCP, DNS etc), law enforcement procedures and more.
o They should quantify scaling characteristics of deployment modes
for each technology model and intersections during co-existence
(e.g. if some of the Network is DS-Lite and some is classical Dual
Stack; peak load on NAT64; etc.).
o The documents should include security considerations for their
specific transition scenario(s).
A desirable outcome would be a set of Best Current Practice (BCP) or
advisory (Informational) documents for a range of generic deployment
models and how they fit into a network, including key services such
as subscriber authentication, DHCP, and DNS. However, it must not be
forgotten that every service provider is different and such documents
can never replace specific deployment plans drawn up by each
individual service provider.
3. Security Considerations
Service providers will insist on having security for IPv6 services,
and for all transition technologies, that is at least as good as for
IPv4 services in all respects. Particular attention must be paid to
security exposures that are specific to transition and coexistence
mechanisms. Thus, all recommendations for transition scenarios must
include any security aspects that are specific to that scenario.
4. IANA Considerations
This document makes no request of the IANA.
5. Acknowledgements
Useful comments and contributions were made by Randy Bush and other
members of the V6OPS WG.
This document was produced using the xml2rfc tool [RFC2629].
6. Change log
draft-ietf-v6ops-v4v6tran-framework-01: small addition following
WGLC, 2011-02-02
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draft-ietf-v6ops-v4v6tran-framework-00: adopted by WG at IETF 79,
2010-12-01
draft-carpenter-v4v6tran-framework-00: original version, 2010-08-18
7. Informative References
[I-D.arkko-ipv6-transition-guidelines]
Arkko, J. and F. Baker, "Guidelines for Using IPv6
Transition Mechanisms during IPv6 Deployment",
draft-arkko-ipv6-transition-guidelines-14 (work in
progress), December 2010.
[I-D.ietf-6man-node-req-bis]
Jankiewicz, E., Loughney, J., and T. Narten, "IPv6 Node
Requirements RFC 4294-bis",
draft-ietf-6man-node-req-bis-07 (work in progress),
December 2010.
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
June 1999.
[RFC4029] Lind, M., Ksinant, V., Park, S., Baudot, A., and P.
Savola, "Scenarios and Analysis for Introducing IPv6 into
ISP Networks", RFC 4029, March 2005.
[RFC4294] Loughney, J., "IPv6 Node Requirements", RFC 4294,
April 2006.
[RFC5211] Curran, J., "An Internet Transition Plan", RFC 5211,
July 2008.
[RFC6036] Carpenter, B. and S. Jiang, "Emerging Service Provider
Scenarios for IPv6 Deployment", RFC 6036, October 2010.
Authors' Addresses
Brian Carpenter
Department of Computer Science
University of Auckland
PB 92019
Auckland, 1142
New Zealand
Email: brian.e.carpenter@gmail.com
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Sheng Jiang
Huawei Technologies Co., Ltd
Huawei Building, No.3 Xinxi Rd.,
Shang-Di Information Industry Base, Hai-Dian District, Beijing
P.R. China
Email: shengjiang@huawei.com
Victor Kuarsingh
Rogers Communications
Canada
Email: Victor.Kuarsingh@rci.rogers.com
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