Patent ID: 8472618

Claim:
A method of controlling a network switching device, wherein the network switching device comprises: an interface block that sends and receives packets; a first switching block that holds switching information and performs, based on the switching information, switching process of packets sent or received by the interface block; and one or more second switching blocks capable of performing the switching process instead of the first switching block, wherein the first switching block and the second switching block are each provided with a plurality of operation modes, and wherein the method comprises: (A) setting the operation mode of a target switching block to a operation mode that is different from the operation mode of the first switching block while the first switching block is handling the switching process, the target switching block being one switching block selected from the second switching blocks; (B) performing a switchover process including starting the switching process using the target switching block instead of the first switching block, after completion of setting the operation mode of the target switching block; and (C) copying the switching information held by the first switching block to the target switching block, prior to starting the switching process using the target switching block, after completion of setting the operation mode of the target switching block.