A system includes a first switch, a second switch, and a processing device. The first switch detects a failure occurring at a first port, generates failure information on the first port when the failure occurring at the first port is detected, and transmits a failure notification packet including the failure information to another switch through a port other than the first port. The second switch transmits a selection-condition-added packet through a port which is coupled to the processing device, the selection-condition-added packet being obtained by adding, to the failure notification packet, selection condition information indicating a selection condition that a second port is selected as a port to relay a packet, the second port having received the failure notification packet through the another switch. And, the processing device performs a path control of a packet based on selection condition information extracted from the selection-condition-added packet received.