Disclosed is a network management system that allows a system to be easily rebuilt, even when there is a switch in the configuration of cars, etc. Surveillance equipment, which includes surveillance cameras (1-1 to 1-4, ...) and image recording devices (1-5, ...), is networked in each car (21a, 21b, ...). Each of said car networks is configured as a LAN, and an inter-car network is configured as a WAN by connecting a router (1-10 (RT1), ...) to the LAN of each car. For the surveillance equipment in each car, identical equipment and equipment installed in identical locations in each car is connected to ports with identical port numbers, and allocated identical LAN addresses. Also, for access from the WAN side, which equipment is accessed is defined solely by the difference in port number, and it is possible to configure the network information of a switched car merely by changing the WAN address setting of the router, ...