<?php
 
/*** an IP address ***/
$ip = "2001:0db8:85a3:08d3:1319:8a2e:0370:7334";
 
/*** try to validate as IPV6 address ***/
if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) === FALSE)
{
echo "$ip is not a valid IP";
}
else
{
echo "$ip is valid";
}?>