Shulou(Shulou.com)06/02 Report--

This article mainly introduces what the proxy server refers to, the article is very detailed, has a certain reference value, interested friends must read it!

A proxy server (Proxy Server) is a physical machine or application that acts as a middleware between a client and a resource provider or server. The proxy server is the transit station of the network information and the intermediary agency between the personal network and the Internet service provider. It is responsible for forwarding legitimate network information, controlling and registering the forwarding.

The function of proxy server (Proxy Server) is to proxy network users to obtain network information. Vividly speaking, it is the transit station of network information and the intermediary agency between personal network and Internet service provider. It is responsible for forwarding legitimate network information, controlling and registering the forwarding.

As a bridge between Internet and Intranet, proxy server plays an extremely important role in practical applications. It can be used for many purposes, the most basic function is connection, in addition, it also includes security, cache, content filtering, access control management and other functions. More importantly, the proxy server is an important security function provided by the Internet link-level gateway, and its work is mainly in the dialogue layer of the Open Systems Interconnection (OSI) model.

Classification of proxy servers

HTTP Agent

Www is all too familiar to anyone surfing the Internet. Www connection requests are based on the http protocol, so we use http agents when browsing the web and downloading data (which can also use the ftp protocol). It is usually bound to the proxy server on ports 80, 3128, 8080, and so on.

Socks Agent

The proxy server using socks protocol is SOCKS server, which is a general proxy server. Socks is a circuit-level underlying gateway developed by DavidKoblas in 1990 and has been an open standard of the Internet RFC standard ever since. Socks does not require applications to follow a specific operating system platform. Unlike application-layer agents and HTTP-layer agents, Socks agents simply pass data packets, regardless of what kind of application protocols (such as FTP, HTTP and NNTP requests). Therefore, the Socks agent is much faster than other application layer proxies. It is usually bound on port 1080 of the proxy server.

In practical application, SOCKS agent can be used in all kinds of game applications, such as e-mail, newsgroup software, network paging ICQ, network chat MIRC and using proxy server to play games.

VPN Agent

The technology of establishing a private network on a shared network. The reason why it is called virtual network is mainly because the connection between any two nodes of the whole VPN network does not have the point-to-point physical link required by the traditional private network construction, but a logical network based on the network platform provided by the public network service provider ISP. Users' data is transmitted through the logical tunnel (Tunnel) established by ISP in the public network (Internet), that is, point-to-point virtual private line. Through the corresponding encryption and authentication technology to ensure the secure transmission of users' internal network data on the public network, so as to truly realize the exclusivity of network data.

Reverse proxy

The reverse proxy server is set up on the server side to alleviate the workload of the server by buffering frequently requested pages.

Other types

FTP proxy: the ability to proxy FTP software on the client to access the FTP server.

RTSP proxy: Realplayer on the proxy client accesses the Real streaming server.

POP3 agent: the mail software on the agent client uses POP3 to send and receive mail.

The function of proxy server

The function of proxy server is to represent network users to obtain network information. Vividly, it is the transit station of network information. The proxy server is like a large Cache, which can significantly improve the browsing speed and efficiency. More importantly, the proxy server is an important security function provided by Internet link-level gateways. The main functions are:

(1) set up user authentication and accounting functions, which can be accounted for by users, and users without registration do not have the right to access the Internet network through the proxy server. And carries on the statistics to the user's visit time, visit place, information flow.

(2) hierarchical management of users, setting access rights of different users, filtering external or internal Internet addresses, and setting different access rights.

(3) increase the Cache, improve the access speed, create buffers for frequently accessed addresses, and greatly improve the access efficiency of popular sites. Usually, the proxy server sets up a large hard disk buffer (which may be as high as several GB or more). When external information passes through, it is also saved in the buffer. When other users access the same information again, the information is directly taken out of the buffer and passed to the user to improve the access speed.

(4) connect the intranet to the Internet and act as a firewall (Firewall): because all intranet users access the outside world through a proxy server, only one IP address is mapped, so the outside world cannot directly access the intranet; at the same time, IP address filtering can be set to restrict the access rights of the intranet to the outside world.

(5) Save IP overhead: the proxy server allows the use of a large number of pseudo-IP addresses, saving network resources, that is, using the proxy server can reduce the demand for IP addresses.

The above is all the contents of the article "what does the proxy server mean?" Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.