Patent ID: 8218446

Claim:
A frame transfer route confirmation method of a network for transferring a data frame transmitted from a transmission source terminal to a destination terminal, comprising the steps of: when changing a network structure, applying identification information, by a hardware node, to an address whose output destination is to be changed in a forwarding table to leave said address; and transferring, by the hardware node, said request message based on an ordinary address to confirm a route or transferring the message based on the address left with said identification information applied to confirm a route, wherein when applying identification information to an address whose output destination is to be changed in said forwarding table to leave said address, with said forwarding table provided with a flag field indicative of before network structure change and after change, a value of a flag is changed to on at the time of changing the network structure, and with said flag information stored in said request message, a route confirmed by designating whether transfer is made according to an ordinary address or transfer is made according to the address left with said identification information applied.