US Patent 7580407 Method and apparatus for forwarding packet

A packet forwarding apparatus has link aggregation capability and prevents the occurrence of flooding when forwarding a packet to a link of a trunk. The packet forwarding apparatus includes sections for learning the source address and a receiving path of the packet by learning information for identifying a port through which to receive the packet, a trunk of a link connected to the port, and a change in the receiving path of a packet received by the trunk, packet forwarding processing unit for, when a receiving path of packets having the same source address is changed in the trunk, selecting one link from among a plurality of links of the trunk in order to forward a packet having a destination address that is the same as the source address and forwarding the packet, and a learning requesting unit for requesting the performance of learning for the packet inside the packet forwarding apparatus.