COMMUNICATION NETWORK SYSTEM

PROBLEM TO BE SOLVED: To actualize a screen display which enables more efficient network management by enabling an administrator to recognize the occurrence of trouble to a managed device and its recovery timely. SOLUTION: A network managing device 10 receives an autonomous report alarm regarding trouble occurrence or recovery from the managed device 20 in a management protocol 105d and manages it by management middleware 105c. The management middleware 105c manages respective managed devices as device icons symbolizing the respective devices. An autonomous report display application 105a while retrieving a device icon that the management middleware 105c manages by referring to the alarm source address at the time of the reception of the autonomous report alarm refers to the trouble management information in the autonomous report alarm and displays the device icon at a display part 104 in a color indicating the trouble occurrence or recovery.