摘要 |
A flow state monitoring part obtains a frame that is output from firewall units using former and new rules, and monitors a flow state to which each of the former and new rules is applied. When the flow has ended for both the former and new rules, the flow state monitoring part notifies a frame holding part of the end of the frame. Upon receiving the notice of the end of the flow, the frame holding part outputs two captured information items each including a group of frames for the flow in accordance with each rule to a flow comparison part. The flow comparison part compares the two captured information items, and abandons those captured information items if they completely coincide with each other. If there is a difference, the flow comparison part outputs those captured information items. |