1 <?php

     2 

     3 /**

     4  * @author Bettina Schwarzer, Fritz-Haber-Institut

     5  * @copyright 01/2014

     6  */

     7 

     8 function isintern($ip)

     9 {

    10         if (!preg_match("/^141\.14\./", $ip) &&

    11             !preg_match("/^172\.(1[6-9]|2[0-9]|31)\./", $ip) &&

    12             !preg_match("/^10\.0\./", $ip)) {

    13                 echo "extern: ".$ip. "<br />";

    14                 return false;

    15         }

    16         else 

    17         {

    18             echo "intern: ".$ip. "<br />";

    19             return false;

    20         }

    21 }

    22 

    23 isintern($_SERVER["REMOTE_ADDR"]);

    24 echo ", ".ip2long($_SERVER["REMOTE_ADDR"]);

    25 echo "<br /><br />";

    26 foreach(array('171.15.255.555',

    27               '172.16.0.0', 

    28               '172.24.3.3', 

    29               '172.16.3.3',

    30               '172.18.3.3',

    31               '172.24.3.3',

    32               '172.31.255.255',

    33               '172.32.0.0',

    34               '10.0.1.128',

    35               '123.123.123.123',

    36               '8.8.8.8',

    37               '141.14.127.255',

    38               '141.14.128.0',

    39               '141.14.143.255',

    40               '141.14.144.0',

    41               '141.14.141.141') as $ip) { 

    42                 isintern($ip);

    43                 }

    44 echo "<br /><br />";

    45 

    46 function islocal($ip) {

    47   foreach(array('172.16.0.0/12', '141.14.128.0/20','10.0.0.0/8') as $net) {

    48     list($subnet, $mask) = explode('/', $net);

    49     if ((ip2long($ip) & ~((1 << (32 - $mask)) - 1) ) == ip2long($subnet)) return true;

    50   }

    51   return false;

    52 }

    53 

    54 

    55 

    56 foreach(array('171.15.255.555',

    57               '172.16.0.0', 

    58               '172.24.3.3', 

    59               '172.16.3.3',

    60               '172.18.3.3',

    61               '172.24.3.3',

    62               '172.31.255.255',

    63               '172.32.0.0',

    64               '10.0.1.128',

    65               '123.123.123.123',

    66               '8.8.8.8',

    67               '141.14.127.255',

    68               '141.14.128.0',

    69               '141.14.143.255',

    70               '141.14.144.0',

    71               '141.14.141.141') as $ip) {

    72 

    73   if (islocal($ip)) echo "$ip local<br>\n";

    74   else echo "$ip extern<br>\n";

    75 }

    76 

    77 ?>