Cant make connection between ethernet shield and Arduino

I am doing Home automation based on Arduino ethernet shield using Android studio. I have done almost the project but when I connect Arduino with android it dose not give function for instance: I tried to switch on a light in order to test but when I try to switch on from android app it dose not work.

I am connecting android and Arduino using IPV4 address of router.

plz anyone can help me its my FYP.

thanks

Hi,
You don't provide enough info to help you.What did you have done to debug the problem?
How does your android app talks to the arduino? http get, mqtt...

I would suggest you try it from a web browser, if that works the problem is on the android side, if not it is on the Arduino side. This is not inclusive but a starting point. This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil