The current proxy server is installed in a computer on the local area network in the form of software. At the same time, the computer has an exit so that the router can access the Internet, and there are many access methods that can be selected.
There are many ways to access the router, and routing technology has gradually improved and upgraded, here we introduce the router to access the Internet with a proxy server concept for small user groups or home users access to Internet, Using a proxy server to access the Internet via dial-up or ADSL is a cheap and practical way. For small and medium enterprises, routers can be connected to the Internet.
proxy server to access the Internet principle
proxy servers are now installed in a computer local area network in the form of software, the computer has an exit access Internet, the access mode can be 10/100M Ethernet interface of the metropolitan area network, ISDN, PSTN, or ADSL. The other Ethernet interface is generally interconnected with the internal LAN. Due to the lack of legal IP address, the internal local area network is generally adopted. Illegal IP addresses, which are generally not accessible to the external network as the source address of the IP packet. When a computer in the local area network needs to access the external network, the access request of the computer is intercepted by the proxy server, and the proxy server finds the local cache, and if the requested data (such as a WWW page) can be found, the data is directly transmitted to the local area network. The requesting computer in the network; otherwise the proxy server accesses the external network, obtains the corresponding data, and caches the data, and sends the data to the requesting computer. However, the data in the proxy server cache needs to be constantly updated.
Using a router to access the Internet
When using a router to access the Internet, you can use (NAT) address translation technology to implement an internal network when a legitimate IP address is missing. Access to external networks. When the router accesses the IP data packet of the external network to the computer in the internal network, the illegal IP address is converted into a legal IP address, and the source address of the IP data packet is accessed to the external network, and when the returned data packet passes through When the router converts the destination address of the data packet to the host IP address in the corresponding local area network, and transmits the data packet to the corresponding host, thereby achieving the purpose of accessing the Internet. These features are actually part of NAT (Network Address Translation).
addition to NAT, the router access Internet also uses firewall technology, mainly based on source and destination IP address and port filtering firewall technology. Through the firewall technology, the internal LAN can be protected from external attacks to a certain extent, which plays a certain security role.
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on the whole, the benefits that can be obtained using a router access
two access methods are more based on the following points: powerful. Use router access to get powerful firewall functions, VPN functions, and more. There are many options for access methods. DDN, Frame Relay, etc. can be used.
network performs better than using a proxy server. The proxy server is installed on the computer, and the performance is not very good because the computer does not specifically handle IP packets. It is convenient for users to publish WWW information. Establishing a WWW website and providing external WWW information, it is impossible to use a proxy server, mainly because the WWW server needs a legal IP address or maps the illegal IP address of the WWW server to a legal IP address through NAT, and at the same time, it needs to provide sufficient processing of external data requests. Ability. In this case, you can choose a router.
overall investment is not very high. When using a proxy server, for a network with more nodes in the LAN, since the computer dedicated to the proxy server cannot handle other work (otherwise the performance of the network access is lower), in contrast, investing in a router and Investment proxy server software plus a computer, the difference is not great.