There is an existing device with a network interface. After it is plugged into the router of the LAN, if the default configured IP and gateway of the device are not in the same network segment as the current network, the device can be scanned and discovered through the tools provided by the manufacturer, and Configure the device;
The current problem is that the device should not be accessible through the network without configuring the IP and gateway; how do they achieve the detection of the device, and what is the principle?