It works on my iPad Pro 9.7. I initially had issues as well, but three things made the difference for me.
1) make sure that you are connected to a network that uses DHCP to assign IP addresses. To date, there is no place to enter an IP address for the Ethernet Adapter.
2) Check the power adapter - use one that is truly compatible with the iPad. (This one may not be the most critical - depending on which adapter you use. I have since gotten this to work even with the power adapter removed). It may affect whether or not your iPad is truly charging though (i.e. battery indicator on iPad is green).
3) Patience and retry: I initially plugged in all the cables (Ethernet and external power) into the adapter prior to plugging in the lightening connector to the iPad Pro 9.7. I found that periodically, I had to remove and replug the USB to Ethernet adapter and then wait about 15s+ before it actually started working. This one was the most common issue for me.
Christopher C.'s YouTube video helped me the most:
https://youtu.be/vnaEWwBY7Dw
BTW. I have tried both the Apple adapter and an Anker USB Hub w/ Ethernet and they both work. I do like the fact that the green indicator light on the Anker USB Hub goes solid green when you have a good Ethernet connection. I used a speed test app and got very good speed (90 Mbps download and 12 Mbps upload) to the Internet.