Abstract: A network monitoring system according to the present disclosure comprises a terminal server that is console-connected to a plurality of network devices, and a network management device that monitors console output information from the terminal server. The network management device comprises: a monitoring means that monitors whether or not abnormality information indicating abnormality in firmware is included in console output information items outputted from the network devices; and a notification means that, if abnormality information is included in any of the console output information items, identifies the network device that outputted the abnormality information and provides a notification.

Abstract: A network monitoring device according to the present disclosure comprises an inoperativeness detecting means that detects that a network device being monitored has become inoperative, and a task indication means that indicates, to the network device that has become inoperative, a task including console connection to a management terminal.

Abstract: A network monitoring device according to the present disclosure is provided with an authentication history collection means that collects an authentication history of access to a management function of a network device to be monitored, a statistic calculation means that calculates statistic information of the authentication history, and a display means that displays the statistic information.