I have a TCP server app that is written in C#. I accept TCP clients that comes from 1234th port of my server IP address. I do not know MAC addresses of TCP clients. There is no problem up to now, server runs perfectly but i realized that when TCP clients with same MAC addresses connects to the server, i could not handle their connections. What is the problem in that sitation? How can i learn the MAC address of TCP client that attempts to connect to my server? IF i can learn that, i would not accept TCP client that has the same MAC address in the connected clients' list.
This is a problem for the netadmin, not the guy who writes the server. Two identical MAC addresses in a LAN is a procurement error, or a netadmin error if dynamically allocated. Don't write code to fix problems that shouldn't arise. You would have trouble sending ordinary responses to such clients, let alone pinging them.