| 摘要 |
Communication of a terminal accessing a network by using a static IP address is cut off. A packet transfer device includes plural ports, a protocol processing unit and a control unit. An IP address distribution request by a DHCP protocol from a client terminal is transferred to a DHCP server, and an application of the IP address distribution is received. At that time, the packet transfer device stores information (IP address, MAC address) of the client terminal into a storage unit. Besides, information (IP address, MAC address) of the client terminal is stored into the storage unit also from an ARP packet by ARP resolution by the client terminal or ARP resolution by the packet transfer device itself. When the IP addresses of the stored DHCP packet and the ARP packet coincide with each other, port filtering is performed to the client terminal having transmitted the ARP packet.
|
