Pre-req:
+ Must have php5 with –enable-sockets
What is a magic packet?
It’s a udp packet sent through the broadcast address to all servers on the network (ie, all servers serviced by the broadcast address). It’s called magic, because the format of the message is so strange. A mac address looks like this, 00:30:1B:BA:FA:47, it’s a series of 6 hexidecimal numbers. The magic packet message is a 6 char header, then the mac address, converted to a character sequence, repeated 16 times.
Available from the PEAR website, http://pear.php.net/package/Net_IPv4, the Net_IPv4 package is pretty cool. Check this out:
<?php
require_once(“IPv4.php”);
$ip = $argv[1];
$netmask = $argv[2];
$ip_calc = new Net_IPv4();
$ip_calc->ip = $ip;
$ip_calc->netmask = $netmask;
$ip_calc->calculate();
$ip_calc->min = $ip_calc->network;
$ip_calc->max = $ip_calc->broadcast;
$ip_calc->min_long = $ip_calc->ip2double($ip_calc->network);
$ip_calc->max_long = $ip_calc->ip2double($ip_calc->broadcast);
$ip_calc->gateway = long2ip($ip_calc->max_long-1);
print_r($ip_calc);
?>