A server according to the present invention includes: a memory; and at least one processor coupled to the memory, the processor performing operations, the operations includes: storing topology information indicating a topology of a network composed of a plurality of switches; generating network route information indicating a communication route on the network based on the topology information; acquiring, from the switch, a transfer entry learned by the switch based on switch route information indicating a broadcast domain to that a port of the switch included in the network belongs; and mapping the transfer entry and the network route information to the topology information.