Store IPv6 in database

Question

What's the best practise to store IP's with PHP in MySQL database? There's a function called ip2long - but this is just for IPv4. But what about IPv6?

I know a php function that is for IPv6 IP's, but it doesn't work on Windows with PHP < Version 5.3

Answer 1

knittl was closer, instead of binary(16) use varbinary(16) as user196009 answered in a related question. It works for me. How?

Storing IP:

<?php
  $query = "insert into stats(vis_ip, id_stat) values('" . inet_pton('66.102.7.104') . "', '1')"; // google's IP address
  // using a PDO wrapper. http://www.phpclasses.org/package/5206-PHP-Execute-database-queries-from-parameters-using-PDO.html
  include_once 'db.php';
  $c = new DB();
  $visit = $c->getResults($query); // stored as binary
?>

Retrieving IP:

<?php
  $query = "SELECT `vis_ip` FROM `stats` WHERE `id_stat`=1";
  // PDO wrapper
  include_once 'db.php';
  $c = new DB();
  $stats = $c->getRow($query);
  echo inet_ntop($stats->vis_ip); // outputs 66.102.7.104
?> 

It should work with IPv6 addresses (I have an IPv4 connection). I'm not an expert so I don't know yet if varbinary length is correct, but how I said, it works for me.

In order to check if 'IPv6 Support' is enabled in your PHP version/host:

<?php
  phpinfo(INFO_GENERAL); // http://php.net/manual/es/function.phpinfo.php
?> 

Answer 2

The dotted-decimal IPv4 address can be converted to an integer, with a maximum size of 32 bits. IPv6 addresses are 128 bits. Since 128 bits do not fit in a PHP int, this will be a pain to work with in PHP.

If you just want to connect and use IPv6 addresses, save yourself the trouble and save them as text. If you want to apply netmasks and calculate subnets, then you need to convert them.