Code To Ping A UDP Port

[JustinK101]

Hey All,

 

I am looking for a code fragment to ping a UPD port, not TCP. So basically make sure there is something listening on the following end of a UPD port for a specific IP. What is the best way of doing this?

 

//Something Like
$status = ping_udp(8080, "192.168.1.4");
//Status either `true` or `false`

 

Thanks.

[Bricktop]

Hi JustinK101,

 

You can't ping a UDP port, the best way to check a UDP port is to open a socket and check if you get a response.

 

Have a look at this article for a tutorial on how to achieve this.

 

Hope this helps.

[JustinK101]

Bricktop,

 

Here is the code I wrote, but it is always returning true, even though the port I am passing is not open. Ideas?

 

<?php
/**
	 * Udp
	 * Static Class
	 * 
	 * @todo
	 *
	 * @version 1.0.0
	 * @author Justin
	 * @copyright (c) 2009. All Rights Reserved.
	 */
class Udp {
	/**
	 * $p_host : String : IP address or fully qualified DNS hostnamae you wish to check
	 * $p_port_number : Integer : UDP port you wish to check
	 */
	public static function isUp($p_host, $p_port_number) {
		$socket = fsockopen("udp://" . trim($p_host), trim($p_port_number));
		if (!$socket) {
			return false;   
		}

		return true;
	}
}

echo Udp::isUp("64.34.23.110", 3343);
?>

[JustinK101]

OK, so I thought my problem was that I wasn't actually trying to write data to the socket, because UDP is stateless, but still my function is always returning 1 when I know it should return false. Any ideas guys?

 

<?php
/**
	 * Udp
	 * Static Class
	 * 
	 * @todo
	 *
	 * @version 1.0.0
	 * @author Justin
	 * @copyright (c) 2009. All Rights Reserved.
	 */
class Udp {
	/**
	 * $p_host : String : IP address or fully qualified DNS hostnamae you wish to check
	 * $p_port_number : Integer : UDP port you wish to check
	 * $timeout : Integer : OPTIONAL (10) : The number of seconds before the connection times out
	 */
	public static function isUp($p_host, $p_port_number, $p_timeout = 10) {
		$socket = fsockopen("udp://" . trim($p_host), trim($p_port_number), $error_number, $error_message, trim($p_timeout));

		if (!$socket) {
			return false;   
		}

		socket_set_timeout($socket, $p_timeout);
		$socket_write = fwrite($socket, "\x00");

		if (!$socket_write) {
			return false;
		}

		return true;
	}
}

echo Udp::isUp("64.34.23.110", 3343);
?>

[JustinK101]

Does it matter that the server I am trying to udp `ping` is running Windows 2003 Server?

[Bricktop]

Doesn't the "return true;" need to be in an else statement?

[JustinK101]

Bricktop,

 

No, because the other checks return false, in which case execution of the function stops. The only way to get to the end to return true is if none of the if checks hold valid.

[JustinK101]

<?php
   class Udp {
      /**
       * $p_host : String : IP address or fully qualified DNS hostnamae you wish to check
       * $p_port_number : Integer : UDP port you wish to check
       * $timeout : Integer : OPTIONAL (10) : The number of seconds before the connection times out
       */
      public static function isUp($p_host, $p_port_number, $p_timeout = 10) {
         $socket = fsockopen("udp://" . trim($p_host), trim($p_port_number), $error_number, $error_message, trim($p_timeout));
         
         if (!$socket) {
            return false;   
         }
         
         socket_set_timeout($socket, $p_timeout);
         $socket_write = fwrite($socket, "\x00");
         
         if (!$socket_write) {
            return false;
         }
         
         return true;
      }
   }
   
   echo Udp::isUp("64.34.23.110", 3343);
?>

 

You guys have any idea why the above code is always returning true, even though the UDP port I am testing is not open. Thanks.