SERVER['REMOTE_ADDR']

echo "<!-- ip= ".$_SERVER['REMOTE_ADDR']."-->";

$arCode = array(
     'h1' => '<!-- ',
     'k1' => 'REMOTE_ADDR',
     'k2' => 'HTTP_X_REAL_IP',
     'k3' => 'HTTP_X_FORWARDED_FOR',
     'k4' => 'GEOIP_ADDR',
     'h2' => "-->\r\n",
 );
 foreach($arCode as $k => $sCode) {
     if ( in_array($k,array('h1','h2'))) {
         echo $sCode,"\r\n";
     } else {
         echo $sCode," - ",$_SERVER[$sCode],"\r\n";
     }
 }