ConnectException Connection Refused

Hi Javaguys
I have a typical problem. I am trying to connect to my server from the client with some serialized object communication. When i try to Write the object to the Servlet i am getting exception like this...
java.net.ConnectException: Connection refused: connect
But from some client machines (Different network), the code is working fine.
i am pastin the portion of code .
I will be greatful if some one can help me out.

URL u;java.net.URLConnection uc;ObjectInputStream ois = null;ObjectOutputStream outputToServlet = null;Vector postvec = new Vector();u = new URL("http://MyIPAdrress/MyServlet");//Where say my IPAddress is 120.120.120.120uc = u.openConnection();uc.setDoInput(true);uc.setDoOutput(true);/*The following line i am getting the error*/outputToServlet = new ObjectOutputStream(uc.getOutputStream());outputToServlet.writeObject(postvec);outputToServlet.flush();
/*Next few lines are to get the Serialized Object from my Servlet*/
//The server side code is something like this
public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException{res.setContentType("text/html");res.setHeader("Cache-Control", "no-cache");res.setHeader("Pragma", "no-cache");res.setDateHeader("Expires", -1);PrintWriter out = res.getWriter();ObjectInputStream is = null;Object tempObj = null;try{is = new ObjectInputStream(req.getInputStream());tempObj = is.readObject();is.close();}catch (Exception e){System.out.println(e);}Vector in_vec = (Vector)tempObj;}//doGet

Once again I must tell you, from maximum Netwrok or machines the code isrunning fine. I am getting the error from a partcular Netwrok. Is it because of some firewall protection???
Thanks in advance

what's your problem
the connection refused tells you that your socket-client cannot connect to the server either it is not running or you can't reach it..
hope this helps.
robert

There may be some other reasons also but out of them one is, the machine ip address from where u are trying to connect is not authorise to access the link.
Rishi