protected static function checkIPv6CIDR($ip, $cidrnet)
{
$ip = inet_pton($ip);
$binaryip = self::inet_to_bits($ip);
list($net, $maskbits) = explode('/', $cidrnet);
$net = inet_pton($net);
$binarynet = self::inet_to_bits($net);
$ip_net_bits = substr($binaryip, 0, $maskbits);
$net_bits = substr($binarynet, 0, $maskbits);
return $ip_net_bits === $net_bits;
}