Communication system, control device, communication method, and program

In order to make possible, in a network having an address management device that performs address management, both communication from each host to the address management device and centralized routing control, this communication system includes: a plurality of transferring nodes that process received packets according to processing rules in which matching rules for specifying packets to be processed are associated with details of processes to be applied to packets that match the respective matching rules; an address management device that assigns an address to each host; and a control device that first sets, to each transferring node located between each host and the address management device, a first processing rule for achieving communication between said host and the address management device, and then sets thereto a second processing rule for achieving communication between a predetermined network resource and said host to which an address has been assigned by the address management device.