防火墙和路由器的比较（Comparison of firewalls and routers）.doc

防火墙和路由器的比较（Comparison of firewalls and routers） Firewall has become a key component of enterprise network construction. But there are a lot of users in the network that has a router, can achieve some simple packet filtering function, so why use a firewall? Below we for Cisco router NetEye firewall with the industry the most widely used and most representative in terms of security compared to explain why users are in the network routers also need firewall. The one or two devices produce and exist in different backgrounds 1, two devices produce different sources The generation of routers is based on routing of network packets. The router needs to complete the different network data packets for efficient routing, why should routing, routing and routing problems such as whether after simply dont care, care about is: can the different segments of the packet routing and communication. Firewalls are generated by peoples need for security. Whether the packet can reach the destination, the time of arrival and the direction is not the focus of the firewall. The key point is whether this series of packets should pass or not, and whether it will cause harm to the network. 2, the basic purpose is different The basic purpose of a router is to keep the network and data informed. The basic purpose of the firewall is to ensure that any non permitted packets are blocked. Two, the core technology is different The ACL list of the Cisco routers core is based on simple packet filtering, and from the point of view of firewall technology implementation, the NetEye firewall is an application level information flow filtering based on Stateful Packet filtering. The following diagram shows one of the simplest applications: a host within an intranet that provides service to an intranet via a router (assuming the port of service is TCP 1455). To ensure security, routers need to be configured to allow only client access to servers TCP 1455 port on the router - and other rejection. For the current