目前,市场上的路由器一般都拥有内置的防火墙(包过滤防火墙)功能,可以对源IP地址和目的IP地址以及协议端口号进行过滤。基于此,我们可以充分发挥它内建的安全性来控制哪些网络访问哪些服务器资源,更好地保护网络安全。也许在没有购买防火墙软硬件的情况下,它是中小型局域网所采用的最简单有效的安全方法。 Currently, routers on the market generally have a built-in firewall (packet filtering firewall) function, which can filter source and destination IP addresses and protocol port numbers. Based on this, we can give full play to its built-in security to control which network access which server resources, to better protect the network security. It may be the simplest and most effective method of security for small and medium-sized local area networks without the need to purchase firewall hardware and software.