Patent ID: 8270406

Claim:
An apparatus for blocking forged multicast packets, the apparatus comprising: input and output ports connected to user terminals; a forwarding process unit transferring a frame input through one of the input ports to one of the output ports connected to a user terminal having a destination address; a determination unit determining an address of a user terminal connected to one of the input ports from a source address included in the frame; a filtering database storing information on the output port connected to the user terminal having the destination address of the frame based on information received from the determination unit; a multicast gate information unit including information on multicast media access control (MAC) addresses of frames providing a unidirectional multicast service and blocking or forwarding all frames having a corresponding multicast MAC address as the destination address by checking whether the input and output ports are connected to an Internet group management protocol (IGMP) querier or not; and a port information transference unit learning the multicast MAC address of the IGMP querier connected to the apparatus, obtaining information on a port having the multicast MAC address as the destination address from the filtering database, and transferring the information to the multicast gate information unit.