Abstract: When a communication abnormality has occurred, links that are included in the communication path on which the communication abnormality has occurred and that are included in communication paths between nodes that allow communication are excluded while referring to information on physical links between nodes in the communication network and path information specifying at least one link included in communication paths between two points, and thereby the scope of positions that are plausible candidates for having been involved in a failure is narrowed.

Abstract: An unauthorized access prevention system that includes a search unit searching the flowing-in path of the unauthorized access to the services by a Web system disclosed by a user's ISP, a determination unit determining the place to implement a countermeasure for protecting the services from the unauthorized access based on the result of the search, and a notification unit notifying, according to a determination that that the countermeasure is implemented in the flow source that makes the unauthorized access flow into the user's communication network, the determination to the flow source.

Abstract: An unauthorized access prevention system includes a countermeasure method determination unit determining a method of taking countermeasures to protect a destination against unauthorized access based on a rate indicating a probability that predetermined traffic is unauthorized access. The rate is determined by calculating a number of times that the countermeasures were taken and subtracting a number of times that countermeasures were suspended, and dividing the resultant number of times that countermeasures were taken without suspension by the number of times that countermeasures were taken, for the predetermined traffic. The system also includes a storage device storing the number of times that countermeasures were taken and the number of times that countermeasures were taken without suspension. A countermeasure execution control unit controls when to take the countermeasures in the determined method.

Abstract: This invention is to minimize influence to other network by preventing unauthorized accesses such as DDoS attacks and probing by worms. When the blocking apparatuses 10a and 10b detect outbound packets by the DDoS attacks or by the probing by the worm, they carry out the Egress filtering for such outbound packets to prevent the packets relating to the unauthorized access from being sent to the backbone network 1000. Moreover, because a notice to the effect that the unauthorized access is detected is sent to other blocking apparatuses 10c and 10d via the management apparatus 16, for example, the blocking apparatuses 10c and 10d precautionarily carry out the Ingress filtering to prevent the packets relating to the unauthorized access from being sent to the network C and D.

Abstract: When a communication abnormality has occurred, links that are included in the communication path on which the communication abnormality has occurred and that are included in communication paths between nodes that allow communication are excluded while referring to information on physical links between nodes in the communication network and path information specifying at least one link included in communication paths between two points, and thereby the scope of positions that are plausible candidates for having been involved in a failure is narrowed.

Abstract: This invention is to minimize influence to other network by preventing unauthorized accesses such as DDoS attacks and probing by worms. When the blocking apparatuses 10a and 10b detect outbound packets by the DDoS attacks or by the probing by the worm, they carry out the Egress filtering for such outbound packets to prevent the packets relating to the unauthorized access from being sent to the backbone network 1000. Moreover, because a notice to the effect that the unauthorized access is detected is sent to other blocking apparatuses 10c and 10d via the management apparatus 16, for example, the blocking apparatuses 10c and 10d precautionarily carry out the Ingress filtering to prevent the packets relating to the unauthorized access from being sent to the network C and D.

Abstract: An unauthorized access prevention system includes a countermeasure execution status screen generation unit, a countermeasure execution instruction obtaining unit, and a countermeasure execution control unit. With the configuration, the countermeasure execution status screen generation unit generates a screen on which a case where countermeasures are being taken to protect a destination against unauthorized access in traffic entering a predetermined position on a communications network can be identified. The countermeasure execution instruction obtaining unit obtains an instruction to take the countermeasures to be taken for each type of traffic or an instruction to suspend the countermeasures being taken. The countermeasure execution control unit controls to take the countermeasures or to suspend the countermeasures at the instruction.

Abstract: An unauthorized access prevention system that includes a search unit searching the flowing-in path of the unauthorized access to the services by a Web system disclosed by a user's ISP, a determination unit determining the place to implement a countermeasure for protecting the services from the unauthorized access based on the result of the search, and a notification unit notifying, according to a determination that that the countermeasure is implemented in the flow source that makes the unauthorized access flow into the user's communication network, the determination to the flow source.