How to find the IP Address of Client connected to Server?

My client pc is connected to as server pc via sockets over Ethernet, How do I find the IP of this client from the server side code.
The server is dishing out one socket per client in a new Thread.
When I do a csocket.getLocalAddress().toString() on the client socket I still get the Server IP address. (csocket is the socket that the Server has spawned upon a now client connection and passed it to a new Thread).