IKEv2 Mobility and Multihoming

Document Charter IKEv2 Mobility and Multihoming WG (mobike)
Title IKEv2 Mobility and Multihoming
Last updated 2006-04-21
State Approved
WG State Concluded
IESG Responsible AD (None)
Charter Edit AD (None)
Send notices to (None)


The IKE Mobility working group will focus on the extensions to the
IKEv2 protocol required to enable its use in the context where there
are multiple IP addresses per host (multihoming, SCTP) or where the IP
addresses changes in the control of the IPsec host (mobility and

The main scenario is making it possible for a VPN user to move from
one address to another without re-establishing all security
associations, or to use multiple interfaces simultaenously, such as
where WLAN and GPRS are used simultaneously. It is also intended that
the extensions produced by the WG would address specific needs related
to other work in IETF, such as modification of SCTP end points without
renegotiation of the security associations or the movement of
IKEv2-based secure connections to enable Mobile IP signaling to take

An explicit non-goal is the construction of a fully fledged mobility
protocol. In particular, the WG shall NOT develop mechanisms for the
following functions:

 o Hiding of mobility from transport layer protocols or applications
   (beyond what already exists through the use of the tunnel mode). In
   this respect MOBIKE is different from Mobile IP, HIP, and other
   mobility protocols.

 o IP address changes done by third parties (NATs, firewalls etc). In
   particular, MOBIKE shall not replace or modify IKEv2 NAT traversal
   function. MOBIKE handles IP address changes initiated by one of the
   endpoints of the security associations. NAT traversal handles other
   address changes. MOBIKE should not be tightly coupled with the NAT
   traversal function, but it is necessary to specify in which cases
   (if any) they can be used together, and how they interact.

 o Opportunistic authentication or other tools for the reduction of
   configuration effort. The mechanisms specified in this WG are to be
   designed for the traditional VPN use case only.

 o Any optimization of packet routing paths due to mobility.

 o Load balancing. Multihoming is supported only in the sense of
   failing over to another interface; sending traffic over multiple
   addresses using the same SA is not supported.

 o Use of IKEv1.

Work Items

 The goals of the MOBIKE working group are to address the
 following issues:

 (1) IKEv2 mobile IP support for IKE SAs. Support for changing and
     authenticating the IKE SA endpoints IP addresses as requested by
     the host.

 (2) Updating IPsec SA gateway addresses. Support for changing the IP
     address associated to the tunnel mode IPsec SAs already in
     place, so that further traffic is sent to the new gateway

 (3) Multihoming support for IKEv2. Support for multiple IP addresses
     for IKEv2 SAs, and IPsec SAs created by the IKEv2. This should
     also include support for the multiple IP address for SCTP
     transport. This should also work together with the first two
     items, i.e those addresses should be able to be updated too.

 (4) Verification of changed or added IP addresses. Provide way to
     verify IP address either using static information, information
     from certificates, or through the use of a return routability

 (5) Reduction of header overhead involved with mobility-related
     tunnels. This is a performance requirement in wireless

 (6) Specification of PFKEY extensions to support the IPsec SA
     movements and tunnel overhead reduction.