It is possible that the USB Ethernet RNDIS Gadget driver is missing, see below picture.
For Windows 7, see here how to find the correct driver:
http://developer.toradex.com/knowledge-base/how-to-install-microsoft-rndis-driver-for-windows-7
The Windows 10 reports the USB-to-Ethernet-device as USB-serial port on the Control panel. In this case the driver needs to be updated. First download the driver from below:
Then in Control Panel use right mouse click on the USB-serial port and select update driver and select option to "seek driver from your computer" and select "disk" and "browse file" to choose above INF-file to update the device driver software.
If Windows 10 refuses to install the INF-file because of it is not signed file, then do as described in this page to disable the driver signature enforcement and install the driver:
https://www.maketecheasier.com/install-unsigned-drivers-windows10/
Also this youtube video shows how to disable signature enforcement so that you will be able to install the driver:
After the successful driver installation you should be able to "ping 192.168.123.123" if USB cable is connected to the controller board.