An attraction acquisition unit of a first router acquires attraction values of third and fourth routers. When many packets the destination of which is a second router (identifier “A”) are then inputted to the first router, a traffic control unit distributes the many packets among communication interfaces so that a higher volume of traffic is sent to a communication interface with which a larger attraction value is associated. The traffic control unit then sends the many packets via the communication interfaces. As a result, a good part of the many packets are limited to a transmission route via the third router.