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 roaming). 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 place. 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 address. (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 mechanism. (5) Reduction of header overhead involved with mobility-related tunnels. This is a performance requirement in wireless environments. (6) Specification of PFKEY extensions to support the IPsec SA movements and tunnel overhead reduction.