Site Multihoming by IPv6 Intermediation

Document Charter Site Multihoming by IPv6 Intermediation WG (shim6) Snapshot
Title Site Multihoming by IPv6 Intermediation
Last updated 2011-08-02
State Approved
WG State Concluded
IESG Responsible AD Jari Arkko
Charter Edit AD (None)
Send notices to (None)


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
  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.