A configuration of a communication system that is able to effect packet forwarding in accordance with an intended forwarding path even in an environment where a node represented by a Layer-2 switch (L2SW) and a node represented by an OpenFlow switch exist together, is provided. The communication system includes a first node, such as a Layer-2 switch, a plurality of second nodes, equivalent to the OpenFlow switches, and a controller. The controller causes the first node to receive a destination learning packet from one of the second nodes lying on the downstream side of the first node on a preset packet forwarding path. The destination learning packet has a node lying on the downstream side of the first node as a transmission source, so that the controller causes the first node to perform a packet forwarding operation in accordance with the packet forwarding path.