AbstractMobile IP is a protocol which provides a function by which a mobile node (MN) continuously retains a single IP address and continues to use the same IP address, even if the MN moves from the network to which it originally connected (Home Network) to another network. This paper is a study of the advantages of IPsec for MIP applied to IP‐VPN, with a small number of terminals per node and where the subject devices are integrated devices such as non‐personal computer terminals. In order to apply MIP to such an IP‐VPN, a new MFA mode is proposed, in addition to the FA mode and CoA mode which have previously been provided to Mobile IP. In the MFA mode, both the MN and MFA move together. Furthermore, it is proposed to include an autoconfiguration function as well. This can be expected to result in reduced terminal shipping costs. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 9–17, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20385