What is a proxy server (proxy)

First, what is a proxy server?

Proxy server is a server between the browser and the Web server, when you surf the Internet through a proxy server, the browser is not directly to the Web server to retrieve the page but to the proxy server to send a request, the proxy server to retrieve the information required by the browser and sent to your browser. Also, most proxy servers have buffering capabilities, it keeps storing new data on its native memory, and if the browser's requested data already exists on its native memory and is up to date, it does not re-enter the data from the Web server and transmits data directly from the storage to the user's browser. , which can significantly improve browsing speed and efficiency. Proxy Server (proxy) is an important security feature provided by Internet link-level gateways, primarily in the Open Systems Interconnection (OSI)-Type dialog layer, with the main features:

1, connect the Internet and the Intranet as Firewall (firewall): Because all intranet users through Proxy server access to the outside, mapping only to an IP address, so the outside can not directly access to the internal network, and can set IP address filtering, Restrict the access of the internal network to external permissions. For security reasons, many places have established firewall, and using proxy can break through the limitations of the firewall. Similarly, proxy can be used to restrict the blocking of IP addresses and prohibit users from accessing certain Web pages. For example, most domestic proxy is forbidden to access VOA (is the VOA COM not VOA org, the latter is an American volunteer!). ), the forbidden Word will appear as a warning once you attempt to access it. If you want a playboy to the newsstand, you may not only get it, but you will be taught a lesson. It's @#$%^&&* .... This restriction is man-made, different serve to the address of the blockade is different. So one can try another if you can't. (for example, the blockade of Geocities for some time ago)

2, Save the IP cost: As mentioned above, all users only occupy one IP, so do not have to rent too much IP address, reduce the maintenance costs of the network. Of course, there are disadvantages to it, such as many network hackers in this way to hide their real IP address, and escaped surveillance.

3, improve access speed: Typically, the proxy server sets a large hard disk buffer (possibly up to several GB or greater), when the outside information is passed, it is also saved to the buffer, when other users access the same information, then directly from the buffer out of the information to the user, to improve access speed.

Second, what person set up proxy server?

The main proxy server is the ISP and some companies, enterprises and units with intranet. ISP set up proxy server is generally to reduce data traffic, improve the user's browsing speed, it lets its users through the proxy server to access the WWW network, so that for a considerable number of recurrent data access, the proxy server can be directly transmitted to the user without duplicating the download; There are internal network units, They may rent a dedicated line or dial-up Internet, but only this one machine can surf the Internet, then install a proxy server software on it, so the other machines of the intranet can also access the Internet through this proxy server.