protected function _getIp()
    {
        if (!$this->_request()) {
            return null;
        }
        $ip = $this->_request()->getClientIp();

        if ($this->_isValidIpv4($ip)) {
            return $ip;
        }

        // sometimes the value is multiple IPs separated by commas
        // (when there are multiple proxies, for example)
        $ips = explode(',', $ip, 2);
        $ip = trim($ips[0]);
        if ($this->_isValidIpv4($ip)) {
            return $ip;
        }

        return null;
    }