IP주소 알아내기.php

<?php function getRealIpAddr()
{
    if (!empty($_SERVER['HTTP_CLIENT_IP']))   //check ip from share internet
    {
      $ip=$_SERVER['HTTP_CLIENT_IP'];
    }
    elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR']))   //to check ip is pass from proxy
    {
      $ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
    }
    else
    {
      $ip=$_SERVER['REMOTE_ADDR'];
    }
    return $ip;
}
 
echo "your IP address is ".getRealIpAddr()."<BR>";
?>

같은 것인데 더 짧게…

<?php
$domain=$_SERVER['REMOTE_ADDR'];
$domain1 = isset($_SERVER['HTTP_X_FORWARDED_FOR']) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : $_SERVER['REMOTE_ADDR'];
echo "Viewer Server's (Remote) IP Address: <strong>$domain</strong> - ";
echo "Viewer Real (Local-Machine) IP Address: <strong>$domain1</strong>";
?>