Problem with socket programming(Vista)

Question

I'm not sure if this has something to do with windows vista.
I wrote simple echo client and server programs and the client program contains these lines
String hostname="172.16.54.22"; //My comp's IP
int portNo=6666;
mySocket=new Socket(hostname, portNo);
Now the problem is that the client program is able to communicate with the server only when I run both of them in xp machines or if I run the server in vista and client in xp. The client is not able to connect to the server when both the client and server are running in a vista machine or if the server is running in xp and client in vista.
It'd be nice if any of you could throw some light on this issue.
PS:
It doesn't work even if I turn the firewall off
The programs work well when I give hostname="localhost" or hostname="127.0.0.1"
Here are my programs
//EchoClient.java
import java.io.*;
import java.net.*;
import java.util.*;
class EchoClient
     public static void main(String args[])
          String hostname="172.16.54.25"; //My ip address
          int portNo=6666;
          //if(args[1]
          //PrintWriter out=null;
          Socket mySocket=null;
          BufferedReader networkIn=null;
          BufferedReader userIn=null;
          PrintWriter sockOut=null;
          try
               mySocket=new Socket(hostname, portNo);
               networkIn=new BufferedReader(new InputStreamReader(mySocket.getInputStream()));
               userIn=new BufferedReader(new InputStreamReader(System.in));
               sockOut= new PrintWriter(mySocket.getOutputStream());
               System.out.println("Connected to Echo Server\n");
               System.out.println("Enter a series of lines (\"end\" to exit)\n");
               while(true)
                    String myLine=userIn.readLine();
               //     System.out.println(myLine);
                    if(myLine.equals("end"))
                         break;
                    sockOut.println(myLine);
                    sockOut.flush();
                    System.out.println(networkIn.readLine());
          catch(IOException exc)
               System.err.println(exc);
          finally
               try{
               if(networkIn!=null) networkIn.close();
               if(sockOut!=null) sockOut.close();}
               catch(IOException exc){ }
               EchoServer.java
//EchoServer.java
import java.io.*;
import java.net.*;
class EchoServer
     public static void main(String args[])
          int portNo=6666;
          ServerSocket serverSock=null;
          try
               serverSock=new ServerSocket(portNo);
               System.out.println("Echo Server Started\n\n");
               while(true)
                    Socket clientSock=serverSock.accept();
                    new Thread(new EchoServerThread(clientSock)).start();
          catch(IOException exc)
               System.err.println(exc);
     EchoServerThread.java
//EchoServerThread.java
import java.io.*;
import java.net.*;
import java.util.*;
public class EchoServerThread implements Runnable
     public Socket clientSock;
     EchoServerThread(Socket sock)
          clientSock=sock;
     public void run()
          System.out.println("\nAccepted Connection from a Client");
          try{
          BufferedReader in=new BufferedReader(new InputStreamReader(clientSock.getInputStream()));
          BufferedReader userIn=new BufferedReader(new InputStreamReader(System.in));
          PrintWriter out= new PrintWriter(clientSock.getOutputStream());
                    /*In sockIn=new In(clientSock);
          Out sockOut=new Out(clientSock);*/
          String str;
          while((str=in.readLine())!=null)
               out.println(str);
               out.flush();
          System.out.println("Closing Connection from a Client");
          out.close();
          in.close();
          catch(IOException exc)
               System.err.println(exc);
     

Answer 1

Sorry everyone but I'd been giving a wong IP address thinking it's my own. The problem's solved.
Thanks for the response Peter.