PHP套接字已连接但不读取数据

Question

    $socket = socket_create(AF_INET, SOCK_DGRAM, 0);
        socket_set_option($socket,SOL_SOCKET, SO_RCVTIMEO, array("sec"=>2, "usec"=>0));
        $result = socket_connect($socket, $this->ip, $this->port);

        if($result <= 0) {
            echo "connect() failed.\nReason: ($result) \n";
        }
            $data = "\xFF\xFF\xFF\xFF\x54\x53\x6F\x75\x72\x63\x65\x20\x45\x6E\x67\x69\x6E\x65\x20\x51\x75\x65\x72\x79\x00";
            socket_write($socket, $data, strlen($data));

                $out = socket_read($socket, 4096);
                socket_close($socket);
                if($out == null ){
                    echo 'data null';
                }
                else {
                    $queryData = explode("\x00", substr($out, 6), 5);
                    $server['ip'] = $this->ip;
                    $server['port'] = $this->port;
                    $server['name'] = $queryData[0];
                    $server['map'] = $queryData[1];
                    $server['game'] = $queryData[2];
                    $server['description'] = $queryData[3];
                    $packet = $queryData[4];
                    //$app_id = array_pop(unpack("S", substr($packet, 0, 2)));
                    $server['players'] = ord(substr($packet, 2, 1));
                    $server['playersmax'] = ord(substr($packet, 3, 1));
                    $server['bots'] = ord(substr($packet, 4, 1));
                    $server['dedicated'] = substr($packet, 5, 1);
                    $server['os'] = substr($packet, 6, 1);
                    $server['password'] = ord(substr($packet, 7, 1));
                    $server['vac'] = ord(substr($packet, 8, 1));
                    $this->info = $server;
                           echo "<pre>";
                            print_r($queryData);
                            echo "</pre>";
                }
        //error_reporting($oldErrorReporting);

此代码适用于我的旧服务器（centos + php5 + apache2）; 在转移到另一台服务器（ubuntu + php5 + apache2）后，它停止了工作。

当问题不是设置php（它是在套接字支持上），但事实上他根本没有收到请求，虽然没有连接错误，但他背叛了。 可能的原因之一是认为使用外部ip访问服务套接字的问题，但我不知道如何解决它。 提前感谢您的回答！