To optimally connect iSCSI different kind storages in an IP network to a disk controller having iSCSII/F.

The disk controller 110 includes: a front end FCI/F with a host; a back end FCI/F with a magnetic disk; a processor; a main storage part; a front end I/F 112 and a back end I/F 114 for exchanging information with network connection devices which are connected to the network so as to manage the storages. The main storage part stores registration information which expresses the attributes of the network connection devices, access information which includes the security and performance of each network connection device via the network, and ranking information which ranks the respective network connection devices, based on the registration information and access information. The appropriate network connection devices 160, 170 are selected, based on each kind of information including the ranking information.