Packet forwarding apparatus suitable for forwarding extended frame

A packet forwarding apparatus having plural pairs of input and output ports to be identified by a port identifier and forwarding a frame received from each input port to one of output ports specified by a destination MAC address, the packet forwarding apparatus comprising:

• a switching information management table for storing, in association with each destination address, a port identifier indicating a forwarding destination port of a received frame;
• a port management table for storing a transmitting MTU size in association with each port identifier;
• routing means for specifying the forwarding destination port identifier of each received frame in accordance with the switching information management table;
• fragment frame creating means for segmenting a received frame into a plurality of data blocks shorter than the transmitting MTU (Maximum Transmission Unit) size and creating a plurality of fragment frames each including one of said data blocks in its payload when the payload length of the received frame exceeds the transmitting MTU size corresponding to the forwarding destination port identifier indicated by the port management table;
• and
• frame assembling means for temporarily storing a plurality of fragment frames received by one of said input ports and restoring an original frame from the plurality of fragment frames,
• wherein one of said received frame, said fragment frames created by said fragment frame creating means, and said original frame restored by said frame assembling means is selectively forwarded to the output port having the forwarding destination port identifier specified by said routing means.