Internet proxy definition of Internet proxy in the Free Online Encyclopedia.

proxy server

Also called a "proxy," it is a computer system or router that breaks the connection between sender and receiver. Functioning as a relay between client and server, proxy servers help prevent an attacker from invading a private network and are one of several tools used to build a firewall.

The word proxy means "to act on behalf of another," and a proxy server acts on behalf of the user. All requests from clients to the Internet go to the proxy server first. The proxy evaluates the request, and if allowed, re-establishes it on the outbound side to the Internet. Likewise, responses from the Internet go to the proxy server to be evaluated. The proxy then relays the message to the client. Both client and server think they are communicating with one another, but, in fact, are dealing only with the proxy.

Address Translation and Caching
The proxy server is a dual-homed host with two network interfaces and two IP addresses. The IP address on the outbound side of the proxy is the one the Internet sees, and the address of the machine making the request is hidden to the outside world. Proxies are often used in conjunction with network address translation (NAT), which hides all the IP addresses of the client machines on the internal network. Proxy servers may also cache Web pages, so that the next request for that same page can be obtained much faster locally. See NAT and proxy cache.

Other Proxies
Anonymous proxy servers let users surf the Web and keep their IP address private (see anonymous proxy). Although not specifically called a proxy, Internet e-mail (SMTP) is a similar concept because it forwards mail. Messages are not sent directly from client to client without going through the mail server. Likewise, the Internet's Usenet news system (NNTP) forwards messages to neighboring servers. See firewall.

Application Level and Circuit Level
Proxy servers are available for common Internet services; for example, an HTTP proxy is used for Web access; an FTP proxy is used for file transfers. Such proxies are called "application-level" proxies or "application-level gateways," because they are dedicated to a particular application and protocol and are aware of the content of the packets being sent. A generic proxy, called a "circuit-level" proxy, supports multiple applications. For example, SOCKS is IP-based circuit-level proxy server software that supports TCP and UDP applications (see SOCKS).

Forward and Reverse Proxies
In this definition, the proxy servers are used to hide the details of the clients from the servers and are thus known as "forward proxies." However, they can also reside at the Web site to hide the details of the servers from the clients (see reverse proxy).

A Proxy Server in a LAN

In this LAN server illustration, the proxy server sits between two routers in what is known as a "demilitarized zone." See DMZ.

proxy server

Computing a computer that acts as an intermediary between a client machine and a server, caching information to save access time

proxy server [′präk·sē ‚sər·vər]

(computer science)

Software for caching and filtering Web content to reduce network traffic on intranets, and for increasing security by filtering content and restricting access.

1.	(software, security)	Proxy Server - Microsoft's proxy server and proxy gateway, designed to provide extensible firewall and network security. Proxy Server is part of BackOffice.
2.	(programming, World-Wide Web)	proxy server - A process providing a cache of items available on other servers which are presumably slower or more expensive to access. This term is used particularly for a World-Wide Web server which accepts URLs with a special prefix. When it receives a request for such a URL, it strips off the prefix and looks for the resulting URL in its local cache. If found, it returns the document immediately, otherwise it fetches it from the remote server, saves a copy in the cache and returns it to the requester. The cache will usually have an expiry algorithm which flushes documents according to their age, size and access history. Compare proxy gateway.

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No references found	The internet proxy server replaces your internet address for their own, thus hiding your IP address and making it much harder for people to track you. Surfing the Internet Anonymously Explained by Ryan Ginster / Computers and Internet community 0, and has pointed to growing industry acceptance of SOCKS as an internet proxy protocol. Exciting News About SOCKS by Computergram International Map drives, install printers, configure Outlook profiles, modify environment variables, adjust Internet proxy settings, configure RDP connections, and further customize your client machines during user logon. Award-Winning Windows Logon Scripting Editor to Become Open Source by Business Wire	Internet Foundation Classes Internet gateway Internet Go Server Internet Group Management Protocol Internet Information Server Internet Inter-ORB Protocol Internet keyboard Internet Mail Access Protocol Internet map Internet marketplace Internet meme Internet Message Access Protocol Internet monitoring Internet Monthly Report Internet Network Information Center internet number Internet Open Trading Protocol Internet PC Internet phone Internet protocol Internet Protocol Control Protocol Internet Protocol version 4 Internet Protocol version 6 Internet protocols Internet provider Internet proxy Internet Public Library Internet radio Internet refrigerator Internet Registry Internet Relay Chat Internet Research Steering Group Internet Research Task Force Internet roaming Internet router Internet Security Association and Key Management Protocol Internet server appliance Internet Server Application Programming Interface Internet service provider Internet Society Internet speak Internet storage provider Internet Talk Radio Internet telephony Internet Telephony Service Providers Internet time Internet Trojan Internet TV Internet Usage Policy Internet utility Internet video	Internet Protocol Version Internet Protocol Version 4 Internet Protocol Version 4 Internet Protocol Version 6 Internet Protocol Version 6 Internet Protocol Version 6 Control Protocol Internet Protocol Version 6 Forum Internet Protocol Very-High Bit-Rate Digital Subscriber Line Internet Protocol Video Internet Protocol Video on Demand Internet Protocol Video Security Internet Protocol Videoconferencing Internet Protocol Virtual Hosting Internet Protocol Virtual Private Network Internet Protocol-Based Service Control Point Internet Protocol-Based Service Switching Point Internet Protocol/Multi-Protocol Label Switching Internet protocols Internet provider Internet provider Internet provider Internet provider Internet provider Internet Provider Security Internet Provider Service Internet Provider Telephone Carrier Internet providers Internet providers Internet providers Internet providers Internet proxy Internet Psychology Research Institute Internet Public Interest Opportunities Program Internet Public Library Internet Public Library Internet Public Policy Network Internet Publication for General and Integrative Psychotherapy Internet Publishing Pilot Program Internet Publishing Project Internet Publishing System Internet Quick Reference Internet Quotient Touch Down Internet Race Finder Internet radio Internet Radio Equality Act Internet Radio from Tuolumne Internet Radio Linking Project Internet Radio Marketing Group Internet Radio Operating System Internet radio station Internet Range Computational System Internet Ray Tracing Competition Internet Real Estate Consulting Internet Real Estate Express Internet Real Estate Group Internet Reconfigurable Logic

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References in periodicals archive

Encyclopedia browser

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No references found

The internet proxy server replaces your internet address for their own, thus hiding your IP address and making it much harder for people to track you.

Surfing the Internet Anonymously Explained by Ryan Ginster / Computers and Internet community

0, and has pointed to growing industry acceptance of SOCKS as an internet proxy protocol.

Exciting News About SOCKS by Computergram International

Map drives, install printers, configure Outlook profiles, modify environment variables, adjust Internet proxy settings, configure RDP connections, and further customize your client machines during user logon.

Award-Winning Windows Logon Scripting Editor to Become Open Source by Business Wire

Internet Foundation Classes

Internet gateway

Internet Go Server

Internet Group Management Protocol

Internet Information Server

Internet Inter-ORB Protocol

Internet keyboard

Internet Mail Access Protocol

Internet map

Internet marketplace

Internet meme