An access control device causes an information processing device to execute access control between a client device and two or more server devices. The device receives an open request for causing the information processing device to open the port of a port number that is a port number to be transmitted to the client device according to completion of one process of a plurality of processes to be executed on a first server device which is one of the two or more server devices. The device generates information for data transfer for opening the port of the port number based on information for identifying the first server device which transmitted the open request, which is included in the received open request. The device transmits the generated information for data transfer to the information processing device.