Elgg\Http\Request::getClientIp PHP Method

    public function getClientIp()
    {
        $ip = parent::getClientIp();
        if ($ip == $this->server->get('REMOTE_ADDR')) {
            // try one more
            $ip_addresses = $this->server->get('HTTP_X_REAL_IP');
            if ($ip_addresses) {
                $ip_addresses = explode(',', $ip_addresses);
                return array_pop($ip_addresses);
            }
        }
        return $ip;
    }