Site Multihoming by IPv6 Intermediation (shim6)
-----------------------------------------------

Charter
Last Modified: 2010-01-05

Current Status: Active Working Group

Chair(s):
    Kurt Lindqvist  <[email protected]>
    Geoff Huston  <[email protected]>

Internet Area Director(s):
    Ralph Droms  <[email protected]>
    Jari Arkko  <[email protected]>

Internet Area Advisor:
    Jari Arkko  <[email protected]>

Technical Advisor(s):
    Thomas Narten  <[email protected]>

Mailing Lists:
    General Discussion:[email protected]
    To Subscribe:      https://www.ietf.org/mailman/listinfo/shim6
    Archive:           http://www.ietf.org/mail-archive/web/shim6/current/maillist.html

Description of Working Group:

Earlier efforts in this working group completed the Shim6 protocol
specification, documented in RFCs 5533 through 5535. This protocol is
a layer 3 shim for providing locator agility with failover
capabilities for IPv6 nodes. Hosts that employ Shim6 use multiple IPv6
address prefixes and setup state with peer hosts. This state can later
be used to failover to a different set of locators, should the
original locators stop working.

The Shim6 approach has a number of advantages, such as enabling small
sites to be multihomed without requiring a provider independent IPv6
address prefix for the site. But the approach has also been
criticized, e.g., for the operational impacts that the use of multiple
prefixes causes. At this time there is no clear view on how well Shim6
works in practice. Implementation and deployment in select networks is
needed to determine its true characteristics.

The Shim6 working group is chartered to track the implementation and
testing or deployment efforts. The group is also expected to shepherd
to completion a few remaining informational documents that complement
the existing protocol specifications.

The specific work items of the group are:

o Write an implementation and/or deployment experience report.

o Specify socket API extensions. This API enables interactions between
applications and the Shim6 layer for advanced locator management,
and access to information about failure detection and path
exploration. It also enables some applications to turn Shim6 off.

o Complete the work on the applicability draft. This draft explains
in detail in which types of networks Shim6 is applicable, and
what its advantages and disadvantages are. The draft will also
explain how firewalls are impacted by the use of Shim6. Finally,
the draft will also explain how Shim6 can be used in situations
where native IPv6 connectivity is not available, such as using
Shim6 over 6to4.

The group will also work in co-operation with the 6MAN working group
as they continue their efforts in improving IPv6 address selection
mechanisms.

The group shall not work on extensions to the Shim6 protocol itself at
this time. However, new work items can be added through rechartering
as others get completed.

Goals and Milestones:

  Done         First draft of architectural document

  Done         First draft of protocol document

  Done         First draft on cryptographic locators, if required

  Done         First draft on multi-homing triggers description

  Done         First draft on applicability statement document

  Done         WG last-call on protocol document

  Done         WG last-call on cryptographic locators, if required

  Done         WG last-call on multihoming triggers description

  Done         Submit document on cryptographic locators to the IESG, if
               required

  Done         Submit protocol document to the IESG

  Done         Submit draft on multihoming triggers description to the IESG

  Sep 2009       Next revision of the API document

  Nov 2009       First WG draft on an implementation report

  Jan 2010       Submit API document to IESG for publication as Informational
               RFC

  Jan 2010       Next revision of the applicability document

  Dec 2010       Submit implementation report to IESG for publication as
               Informational RFC

  Dec 2010       Submit applicability document to IESG for publication as
               Informational RFC

  Dec 2010       Close or re-charter


Internet-Drafts:

Posted Revised         I-D Title   <Filename>
------ ------- --------------------------------------------
Jul 2005 Nov 2009   <draft-ietf-shim6-applicability-04.txt>
               Applicability Statement for the Level 3 Multihoming Shim
               Protocol (Shim6)

Oct 2006 Jan 2010   <draft-ietf-shim6-multihome-shim-api-12.txt>
               Socket Application Program Interface (API) for Multihoming Shim

Request For Comments:

 RFC   Stat Published     Title
------- -- ----------- ------------------------------------
RFC5533 PS   Jun 2009    Shim6: Level 3 Multihoming Shim Protocol for IPv6

RFC5534 PS   Jun 2009    Failure Detection and Locator Pair Exploration Protocol
                      for IPv6 Multihoming

RFC5535 PS   Jun 2009    Hash-Based Addresses (HBA)