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Concluded WG Sunsetting IPv4 (sunset4)

Note: The data for concluded WGs is occasionally incorrect.

WG Name Sunsetting IPv4
Acronym sunset4
Area Internet Area (int)
State Concluded
Charter charter-ietf-sunset4-02 Approved
Document dependencies
Additional resources Issue tracker, Wiki
Personnel Chairs Marc Blanchet, Wesley George
Area Director Terry Manderson
Tech Advisors Fred Baker, Martin Stiemerling, Stewart Bryant
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Final Charter for Working Group

Global IPv4 addresses, once considered plentiful, are an
increasingly scarce resource for many who wish to connect to the
Internet today. IPv6 provides an abundance of freely available
addresses, and while deployment alongside IPv4 has begun in
earnest, much work remains.

In order to fully transition the Internet to IPv6, individual
applications, hosts, and networks that have enabled IPv6 must also
be able to operate fully in the absence of IPv4. The Working Group
will point out specific areas of concern, provide recommendations,
and standardize protocols that facilitate the graceful "sunsetting"
of the IPv4 Internet in areas where IPv6 has been deployed. This
includes the act of shutting down IPv4 itself, as well as the
ability of IPv6-only portions of the Internet to continue to
connect with portions of the Internet that remain IPv4-only.

While this work obviously spans multiple IETF areas including
Internet, Operations, Transport, Applications, and Routing, this
working group provides a single venue for the consideration of IPv4
sunsetting. Work in this group shall never impede the deployment of
IPv6, will not duplicate functions and capabilities already
available in existing technologies, and should demonstrate
widespread operational need. Cross-area coordination and support
is essential.

Disabling IPv4 in applications, hosts, and networks is new
territory for much of the Internet today, and it is expected that
problems will be uncovered including those related to basic IPv4
functionality, interoperability, as well as potential security
concerns. The working group will report on common issues, provide
recommendations, and, when necessary, protocol extensions in order
to facilitate disabling IPv4 in networks where IPv6 has been

Operational scenarios considered by the working group shall include
IPv6-only nodes and networks as the goal. Work on technologies that
involve increased sharing of global IPv4 addresses should be
limited to what is necessary for communicating with endpoints or
over networks that are IPv6-only.

The initial work items are:

  • NAT64 port allocation and address sharing methods involving
    scenarios where an IPv6-only node is present (and NAT44, as it
    overlaps NAT64 address sharing and port use). This may require a
    description of the use of an existing protocol, the development
    of extensions to an existing protocol, or the definition of an
    entirely new protocol.

  • Gap analysis of IPv4/IPv6 features to facilitate IPv4 sunsetting

  • Provisioning methods to signal a dual-stack host to disable or
    depreference the use of IPv4


Date Milestone Associated documents
Jul 2017 IPv6 Support Within IETF work
Apr 2016 Submit provisioning methods to signal a dual-stack host to disable the use of IPv4 to IESG for consideration as Proposed Standard
Dec 2015 Submit NAT64 port allocation and address sharing methods to IESG for consideration as an Informational RFC
Dec 2015 Submit gap analysis on IPv4 sunsetting to IESG for consideration as an Informational RFC