Abstract: When identifying a maintenance target device that is subject to maintenance in an information system realized by connecting a plurality of devices including a monitoring target device, a maintenance target device identification unit identifies the maintenance target device on the basis of contents of configuration information in the information system or contents of maintenance target device information, and a filtering target device identification unit identifies a filtering target device to be affected by the maintenance of the maintenance target device on the basis of a distance matrix calculated from an adjacency matrix obtained from the configuration information.

Abstract: An alternative route evaluation apparatus manages a network including a plurality of standard routes and a plurality of alternative routes. An alternative route is established for each standard route. Each standard route has, as constituent elements, two or more OFSes. Each alternative route has, as constituent elements, two or more OFSes, a combination of which being different from that of a corresponding standard route. In the alternative route evaluation apparatus, a priority order evaluating unit sets a priority level for each alternative route, based on the amount of relayed packets in the corresponding standard route. For each OFS, an alternative route registering unit selects a particular alternative route from among alternative routes having this OFS as a constituent element, based on the priority level set by the priority order evaluating unit.

Abstract: When identifying a maintenance target device that is subject to maintenance in an information system realized by connecting a plurality of devices including a monitoring target device, a maintenance target device identification unit identifies the maintenance target device on the basis of contents of configuration information in the information system or contents of maintenance target device information, and a filtering target device identification unit identifies a filtering target device to be affected by the maintenance of the maintenance target device on the basis of a distance matrix calculated from an adjacency matrix obtained from the configuration information.