Patent ID: 7895358
Filing Date: 2011-02-22
Classification: H04L

Abstract:
1. A redundancy switching method in a redundant configuration system including a first server which is given a predetermined address and which is in an operating state for providing a service on the basis of the predetermined address, a second server which is a spare for the first server and which is in a standby state, and a switching hub which connects the first server and the second server and through which the first server or the second server communicates with an external network, comprising: the first server sending a system switching notification to the second server in case of redundancy switching at which the first server is to shift from the operating state into a standby state; the second server which is to shift from the standby state into an operating state, setting a filter so as to cut off sending of information for the layer-2 address resolution by viewing the header part of information sent from the second server, upon receiving the system switching notification from the first server, giving the second server itself the same address as the predetermined address given to the first server which is to shift from the operating state into the standby state but avoids duplication of the predetermined address by the filter of the second server, recognizing the given predetermined address and prepares for providing the service, and shifting into the operating state and sending an operatization start notification to the first server; the first server which is to shift from the operating state into the standby state, deleting the given predetermined address, upon receiving the operatization start notification from the second server, sending a notification of the deletion of the predetermined address to the second server, and shifting into the standby state; and the second server releasing the set filter, upon receiving the deletion notification from the first server, and starting provision of the service.