Recoger la IP del cliente con PHP

Recoger la IP pública y la privada.

<?
$ip = @$REMOTE_ADDR; 

echo "<font face='Verdana' size='3'><b>IP Address Proxy= $ip</b><br>";

// Sacar ip real de cada tipo
if (isset( $HTTP_SERVER_VARS["HTTP_X_FORWARDED_FOR"] )) {
 $HTTP_SERVER_VARS["HTTP_X_FORWARDED_FOR"];

} else {

$ip = $HTTP_SERVER_VARS["REMOTE_ADDR"];
} 

echo "<font face='Verdana' size='3'><b>IP Address Real= $ip</b><br>";

?>

<?php
if (getenv("HTTP_X_FORWARDED_FOR")) {
  
  $ip   = getenv("HTTP_X_FORWARDED_FOR");
  $client = gethostbyaddr($_SERVER['HTTP_X_FORWARDED_FOR']);
  
} else {

  $ip   = getenv("REMOTE_ADDR");
  $client = gethostbyaddr($_SERVER['REMOTE_ADDR']);
}

$str = preg_split("/\./", $client);
$i t($str);
$x - 1;
$n - 2;

$isp = $str[$n] . "." . $str[$x];

echo "IP: " . $ip ."<br />ISP: " . $isp . " </div>";
?>