public function getClientIP()
    {
        $ip = null;
        $client = $this->server('HTTP_CLIENT_IP');
        $forward = $this->server('HTTP_X_FORWARDED_FOR');
        $remote = $this->server('REMOTE_ADDR');

        if (filter_var($client, FILTER_VALIDATE_IP)) {
            $ip = $client;
        } elseif (filter_var($forward, FILTER_VALIDATE_IP)) {
            $ip = $forward;
        } else {
            $ip = $remote;
        }

        return $ip;
    }