A source apparatus writes, in a route request packet, the number of routes requested by the source apparatus. When a relay apparatus receives a route request packet for the first time, the relay apparatus determines a waiting time period, based on a route evaluation value that indicates a state of a route through which the route request packet has passed, and starts a timer. The relay apparatus selects route request packets having as high route evaluation values as possible, among route request packets that have been received until the timer expires, the number of route request packets to be selected being equal to the number of routes requested by the source apparatus, and then broadcasts the selected route request packets.