An information processing system comprises an information processing apparatus, a switch, and a storage device, wherein the first communication ports and the third communication ports are connected to the second communication ports. When a response from a storage device to a data input/output request is not received within a predetermined time period, the information processing apparatus transmits a second and a third data input/output requests from the first communication port on the first communication channel, and transmits an inspection request to the switch to inspect a second communication port on the first communication channel. When responses to the second and third data input/output requests are not received within a predetermined time period, and a response to the inspection request is received within a predetermined time period, the information processing apparatus determines that there is a fault in the first communication port on the first communication channel.