<?php

$db_host = 'ff3e:30:fd66:98:5837::';
$db_port = '1433';
$db_name = 'thedb';
$db_user = 'theuser';
$db_pass = 'thepass';

$conn = new PDO("dblib:host=$db_host:$db_port;dbname=$db_name", $db_user, $db_pass);
$conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
$conn = null;

$ nmap -6 -Pn -p 1433 ff3e:30:fd66:98:5837::
Starting Nmap 6.00 ( http://nmap.org ) at 2016-02-05 16:50 CET
Nmap scan report for <hostname> (ff3e:30:fd66:98:5837::)
Host is up (0.0019s latency).
PORT     STATE SERVICE
1433/tcp open  ms-sql-s

Array
(
    [0] => dblib
    [1] => mysql
)