Patent ID: 8223756

Claim:
A network device that performs a packet filtering based on set filter information and performs a transmission and a reception of path information with other network device that is connected to the network device via a network, the network device comprising: a filter setting unit that sets the filter information based on a predetermined request received from either one of the network device and the other network device; a filter-information transmitting/receiving unit that transmits the path information with the filter information added when the filter information is set by the filter setting unit, and receives the path information with the filter information added when the filter information is set in the other network device; a filter-combining determining unit that determines whether redundant filter information that is redundantly set between the network device and the other network device is to be combined or deleted, based on the filter information and the path information received by the filter-information transmitting/receiving unit; and a filter control unit that issues a filter-setting request for combining the redundant filter information to the filter setting unit when it is determined that the redundant filter information is to be combined, and issues a filter release request for deleting the redundant filter information to the filter setting unit when it is determined that the redundant filter information is to be deleted.