Relay device

A relay device connected to a plurality of other relay devices through a plurality of physically different routes to constitute a network, comprising:

• a plurality of physical ports physically connected to the plurality of other relay devices on the network to form physical links;
• a setting unit setting one or more logical links each having a communication band equal to/lower than that of the physical link for each of the physical links;
• an evaluation unit automatically adding an evaluated value based on communication characteristics of the logical link when a control packet is received from a first relay device among the other relay devices through the logical link or the control packet is transferred to a second relay device through the logical link;
• and
• a unit selecting, when there are a plurality of routes from a start-point device among the other relay devices which becomes a transmission start point of the control packet to the relay device, one of the routes based on evaluated values accumulated by the relay devices included in the routes from the start-point device to the relay device.