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From: Robert Klemme <shortcutter@googlemail.com>
Newsgroups: comp.lang.java.programmer
Subject: Re: Ping from JAVA to IP Address
Date: Mon, 24 Oct 2011 20:26:22 +0200
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On 24.10.2011 20:01, sahm wrote:
> 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

Does a command line ping work?  If not you cannot expect it to work from 
Java.  There might be firewalls in between blocking ICMP.

> ============ 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);

AFAIK there is no guarantee that isReachable() does a ping:
http://download.oracle.com/javase/6/docs/api/java/net/InetAddress.html#isReachable(int)

>              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 ===============

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/