MOBIKE

mobility and multihoming Internet key exchange

The MOBIKE protocol is a mobility and multihoming extension to the IKEv2.

Base IKEv2 procedures allow a UE and EPDG to establish a set of SAs between single UE and EPDG IP addresses. However, since the UE typically uses an IP address allocated by the access network (perhaps by the WiFi AP), there are mobility scenarios wherein this “outer” IP address may change. Using the base IKEv2 protocol, the UE would have to delete and re-establish a new set of SAs with the EPDG using this new source address.

MOBIKE allows one or both of the IKEv2 endpoints to change the IP address used for its side of the SA without re-establishing the SA. MOBIKE can be used for both mobility and multihoming scenarios. Multihoming means that the IKEv2 endpoint may have multiple IP addresses and be connected to multiple interfaces. The IKEv2 endpoint can use MOBIKE to switch to a different IP interface after the IKEv2 SA and IPsec SAs have been established. For example, it may choose to try a new IP interface if it notices that it cannot reach its peer using the current IP interface.

In the mobility case, the UE informs the EPDG that is has moved and would like to use a new source IP address. MOBIKE does not change the EPDG IP address.