A network processing apparatus is provided. A send buffer receives from a protocol stack a long packet with a data length exceeding a maximum transmission unit defined for a network and stores the long packet. A payload dividing unit divides the payload of the long packet into a plurality of divided payloads. A header duplicating unit duplicates the header of the long packet so as to generate a duplicated header for the respective divided payload. A short packet generating unit attaches the duplicated header to the respective divided payload so as to generate a short packet with a data length equal to or less than the maximum transmission unit to be sent to the network. A sending unit sends the short packet to the network via a physical interface.