Patent ID: 7639705

Claim:
A packet forwarding apparatus, comprising: a plurality of network interface modules each including a packet transmitting/receiving unit for transmitting/receiving packets to/from a plurality of physical links connected to said plurality of network interface modules; a physical link store unit for storing a plurality of physical links and a logical link of link aggregation aggregated thereto by making the correspondence of the logical link to said plurality of physical links; a first packet switching fabric connected to said plurality of physical links for forwarding packets from/to a packet transmitting/receiving unit of said plurality of network interface modules; an output label store unit for storing output labels and output labels for backup to be added to packets received by said packet transmitting/receiving unit by making the correspondence of the output labels with the logical link; an output label searching unit for searching said output label store unit for a first output label to be added to said packet and for a first logical link to output said packet on the basis of an input label of a packet received by said packet transmitting/receiving unit; a physical link search unit for searching said physical link store unit for a first physical link to output said packet from among said plurality of physical links of said logical link of link aggregation; a failure detection unit for detecting failures in said plurality of physical links; and a detour decision unit for determining, when a failure has been detected by said failure detection unit in said first physical link belonging to the first physical link searched by said physical link search unit, a second label for backup to be added to said packet in place of said first label and for determining a second physical link or a second logical link connected to a second packet switching fabric in place of said first logical link searched by said output label searching unit.