| 摘要 |
PROBLEM TO BE SOLVED: To detect occurrence of a loop on the external network side without producing an unnecessary load on the external network which connects to a centralized control network.SOLUTION: A control device includes: a packet recording unit which records the feature of a packet destined to an external network flowing into the network of a control target; a determination unit which collates the feature of the packet, destined to the external network flowing into the control target network after the recording, with a packet recorded in the packet recording unit, to determine whether the packet destined to the external network flowing into the control target network after the recording flows into the control target network again; and a loop suppression unit which executes a predetermined loop suppression measure, on determination that the packet destined to the external network flowing into the control target network after the recording is the packet which flows in again through the external network.SELECTED DRAWING: Figure 1 |
