To provide a network management system in which a manager can set/refer to a packet relay device without being aware of the boundary of a virtual region.
A packet relay device management unit of a packet relay device 20 holds a virtual network management table, and manages a transmission/reception port and a VLAN belonging to each of virtual packet relay devices 40a, 40b. When a setting request or a reference request is delivered from a network management system 10 to the packet relay device 20, the transmission/reception port and the VLAN receiving the request are grasped by the packet relay device management unit. With reference to a virtual network management table based on each piece of information, the packet relay device management unit recognizes that which of the virtual packet relay devices 40a, 40b is connected to the transmission source of the request, and then processes the setting request or the reference request based on the recognition.
YUMOTO KAZUMA
HIGUCHI HIDEMITSU
KIMURA HIROYASU
Koichi Kikuchi