防火墙是一种用来加强网络之间访问控制的特殊网络互联设备。亡对两个或多个网络之间传枪的数据包按照一定的安全策略进行检查，来决定是否允许网络间的通信，其中被保护的网络称为内部网络，另一方则称为外部网络或公用网络，它能有效地控制内部网络与外部网络之间的访问及数 A firewall is a special networking device used to enhance access control between networks. Packets transmitted between two or more networks are checked according to a certain security policy to decide whether to allow communication between networks. The protected network is called an internal network and the other is called an external network or Public network, it can effectively control the internal network and external network access and number