Ping from JAVA to IP Address

Hi every one

I'm tiring to ping to External IP address (e.x : www.google.com) but I
keep get false every time.
I write function to do the ping. I can ping to local IP address fine,
but when I try to ping any external IP (e.x. www.google.com) it wont
work I keep get false.
this is my code
============ start ===============
package netscan;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class NetPing
{
    boolean reach = false;
    public boolean pinging()
    {
        try
        {
            InetAddress address =
InetAddress.getByName("www.google.com");
            reach =address.isReachable(60000);
            System.out.println(String.valueOf(reach));

        }
        catch(UnknownHostException uhe)
        {
            System.out.println(uhe.toString());
        }
        catch(IOException io)
        {
            System.out.println(io.toString());
        }
        catch(Exception e)
        {
            System.out.println(e.toString());
        }

        return reach;
    }

}
============ end ===============

Best
Salim