In a multi-ring communication network, first and second rings include first and second connection nodes, respectively, that are adjacently connected to each other. The first connection node receives, from adjacent nods, traffic information storing a pair of input and output node identifiers in association with each of storage areas included in a frame to be transmitted, where the input node identifier identifies an adjacent node from which data is inputted, and the output node identifier identifies an adjacent node to which the data is outputted. When the received traffic information includes the output node identifier identifying the second connection node, the first connection node sets a plurality of redundant path segments each including the second connection node, based on the received traffic information, where the plurality of redundant path segments includes a currently-used path segment.