A transfer apparatus is configured to: calculate a total cost of a first route in a first network that starts from a source transfer apparatus and ends at a destination transfer apparatus; obtain a particular cost being a cost between the source transfer apparatus and a first line, which couples the source transfer apparatus and its own transfer apparatus, in a second route, which starts from the source transfer apparatus and reaches the destination transfer apparatus via its own transfer apparatus; calculate a differential between the total cost and the particular cost; set, based on the differential, a cost between its own transfer apparatus and a second line, which couples its own transfer apparatus and the destination transfer apparatus, to a value that causes the source transfer apparatus to select the second route rather than the first route; and notify the cost value to the source transfer apparatus.