C# Sockets - Recognize same computer

Question

I'm doing a software which includes Udp and Tcp sockets server-client. I want that only if the client is connected to the TCP server, the Udp will respond to it. I know how to do that, but I have a problem - if someone will use two different computers on the same LAN, the external IP will be the same and I will have problem checking the tcp/udp connection because of that. So I tought at first that when the client connects to my server, he will send his internal IP and i'll use it to check if it's really one computer or more.

But I don't know if there an easier way, because that one is pretty complicated. Any ideas?

Answer 1

Assign an ID to each connection and make the UDP packets include that ID. Match on ID, not on "internal IP".

There is no good definition for internal IP. A computer can have dozens.