NETWORK MONITORING TERMINAL DEVICE, NETWORK MONITORING SYSTEM AND NETWORK MONITORING METHOD

PROBLEM TO BE SOLVED: To monitor routing lines and/or changes in routing lines, in real time. SOLUTION: The network monitoring terminal device has a link state for notifying information collecting means 21 which collects link state notifying information, including information relative to a network or interface costs, a link state data creating means 22 which creates link state data according to the link state notifying information, a path tree creating means 24 which refers to the link state data and creates a path tree with a minimum cost value to the destination, a path tree storing means 25 which stores the created path tree, a path tree indicating means 28 which indicates the path tree, and a path tree change detecting means 29 which compares the basic path tree and a re-created path tree and detects changes. COPYRIGHT: (C)2006,JPO&NCIPI