Packet distribution system, control device and control method for controlling distribution of content packet

A packet distribution system includes: a first transfer device that is placed on a boundary of a core network and near first and second terminal devices; a second transfer device that is placed on the boundary of the core network and near a content distribution device; and a control device that, when a first content packet is distributed to the first terminal device, a distribution request packet is transmitted from the second terminal device, and a second content packet newly distributed from a content distribution device to the second terminal device is detected by the second transfer device, causes the second transfer device to abandon the second content packet based on control information included in the second content packet, and causes the first transfer device to copy the first content packet distributed to the first terminal device, to the second terminal device.