IP Adresse und Privider auswerten und was ist mit einem Proxi?

[Mike]

Moin Raul,

echo $remotehost = gethostbyaddr(getenv('REMOTE_ADDR'));
    echo $remotehost_proxy = gethostbyaddr(getenv

dieses Konstrukt ist etwas "sicherer":

if (isSet($_SERVER))
   {
    if (isSet($_SERVER["HTTP_X_FORWARDED_FOR"]))
       {
        $realip = $_SERVER["HTTP_X_FORWARDED_FOR"];
       }
    elseif
       (isSet($_SERVER["HTTP_CLIENT_IP"]))
       {
        $realip = $_SERVER["HTTP_CLIENT_IP"];
       }
    else
       {
        $realip = $_SERVER["REMOTE_ADDR"];
       }
   }
else
   {
     if ( getenv( 'HTTP_X_FORWARDED_FOR' ) )
        {
          $realip = getenv( 'HTTP_X_FORWARDED_FOR' );
        }
     elseif
        ( getenv( 'HTTP_CLIENT_IP' ) )
        {
          $realip = getenv( 'HTTP_CLIENT_IP' );
        }
     else
        {
          $realip = getenv( 'REMOTE_ADDR' );
        }
   }

Gruß
Mike