1. An information processing apparatus in a network system including at least three first network apparatuses that establish logical topologies including available logical paths and including a plurality of second network apparatuses that connect to the first network apparatuses and that establish physical topologies, the information processing apparatus comprising: a first storage unit that stores traffic amounts of each of the logical paths between the first network apparatuses, each of the logical paths being available by each of the second network apparatuses and each of ports of the first network apparatuses connecting to each of the second network apparatuses turning on; a second storage unit that stores power consumption for each of connections between the first network apparatuses and the second network apparatuses; and a calculation unit that calculates, for a plurality of logical topologies established by the first network apparatuses, sums of power consumption related to a packet forwarding process between the first network apparatuses and power consumption related to the connections between the first network apparatuses and the second network apparatuses based on the traffic amounts of each of the logical paths between the first network apparatuses and based on the power consumption for each of the connections and that selects a logical topology with the smallest sum among the plurality of logical topologies, wherein the power consumption related to the connections increases in association with increment of number of the logical paths, and the power consumption related to the packet forwarding process decreases in association with increment of number of the logical paths.