Different client connect server but get same IP??

Question

i am doing a server for multiplayer game. when the client connect to server, server need to keep it IP. but why my server always get same IP for every connected client? my code is as below
public class CommServer {
    private Vector clients = new Vector();  // a list of all connected clients
    ServerSocket server;   // the server
    private static int INTPORT=9999;
public static void main(String args[]) {
        CommServer myCS = new CommServer(INTPORT);
   public CommServer(int port) {
        startServer(port);
   private void startServer(int port) {       
        try {
            // --- create a new server
            server = new ServerSocket(port);
             // --- while the server is active...     
            while(true) {
                // --- listen for new client connections
                Socket socket = server.accept();
                CSClient client = new CSClient(this, socket);
                writeActivity(client.getIP() + " connected to the server.");
                // --- start the client thread
                client.start();
        } catch(IOException ioe) {
            writeActivity("Server Error...Stopping Server");
            // kill this server
            killServer();
public class CSClient extends Thread {
    private Thread thrThis;         // client thread
    private Socket socket;          // socket for connection
    private CommServer server;
   protected BufferedReader in;    // captures incoming messages
    protected PrintWriter out;      // sends outgoing messages
public CSClient(CommServer server, Socket socket) {
        this.server = server;
        this.socket = socket;
        this.ip = socket.getInetAddress().getHostAddress();
        // --- initialize the reader and writer
        try {
            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            out = new PrintWriter(socket.getOutputStream(), true);
        } catch(IOException ioe) {
                      killClient();
public String getIP() {
        return ip;
    }please help.. thanks

Answer 1

hi, thanks for reply.
yes, i am trying to connect from different macnine
that have different IP address.
how to check if it asign same external IP toclient?
can it be configure to assign different IP?what he means is, if you run your server at location
A, and all your clients from location B, with the
internet in between, and a single router/switch
serving internet connections to the clients at the B
location, then the server at the A location will see
the external IP of the site B router, not the
individual IPs of the clients behind the router
(since those IPs are only for internal network usage
behind the router)
in short, do you test with multiple clients from one
internet connection? then it would be logical that
they present the same IP to the server. The best (and
most realistic) way to test would be with multiple
clients from multiple locations / internet connectionsok.thanks.
so is it possible for me to get the client machine ip but not the IP for the router? because i will hav multiple user from same location access the server at the same time.