A communication system that performs communication route control includes a center node and at least one node connected thereto via a communication line. The node includes an error-detecting unit that detects an error in the communication route, a route request packet transmitting unit that broadcasts a new route request packet in response to the detection, a route answer packet receiving unit that receives a route answer packet transmitted from a node that is a target node or a node having a valid route to the target node or from the center node, and a communication route updating unit that updates a communication route based on the route answer packet. A node that is the target node or the node having a valid route to the target node or the center node transmits a route answer packet to the node in response to a route request packet transmitted from the node.