Proxies are common in larger networks, but the service can be used in many different ways with many different purposes. There are a large number of toll-free and toll proxy services that work in many different ways.
Because it is the proxy to contact the actual server is its IP address (or any of its IP addresses) that appear in IP packet sender. However often given also the originating address, depending on the protocol used at the higher level. Some proxy service provides users the ability to not reveal its own IP address in this way, in order to conceal or change their identity on the Internet. Such is usually included in anonymity services, which typically combines a proxy service with a VPN tunnel.
Initially, the proxy server to let multiple people use the same modem connection on a secure and simple way. The word proxy translates to the concept of agent, or intermediary. The proxy server then sat on the computer was offline, so that everyone on the network could retrieve documents, files, and other network services through it. The proxy acted as an interface between the Internet and the local network. Later developed the proxy to also store Internet files temporarily in a so-called cache. This could radically reduce Internet traffic because the same information does not have to be downloaded again if someone wanted the same information again. It was a great advantage to avoid having to download the same document several times because of the slow modem connections they had at the time.
The browser on the user's computer can be configured to connect through a proxy server. Instead of a browser on a computer on a network to retrieve the web page directly from the Internet so requests, the browser web pages from a proxy server on its own network. The proxy, in turn, retrieves webinnehållet from the Internet and deliver it to the computer that requested it. This type of proxy is common in companies and to be able to use the service is usually required that one is in the same network as the proxy. Web server out on the Internet noticeable, however no difference because the proxy requests the information in the same way as a normal browser would.
A proxy is usually also register traffic in a log file so that in retrospect can see how the connection has been used. To increase control of Internet traffic further as a proxy set up to analyze and filter the information and thus prevent certain pages or services from reaching clients.
This type of proxy acts as a typical company proxy, with the difference that you do not need to set the client browser to use the proxy. All traffic redirected from the router to the proxy without the clients notice any difference. This reduces administration because you do not have to configure each client. It also increases control because it forces all clients to use the proxy so that all the traffic can be monitored.
A reverse proxy placed in front of a resource, such as a web server, which you want to present to visitors without making it directly accessible. The proxy's purpose may include the desire to hide the underlying network, limit access, perform load balancing or terminate SSL.
Even if the proxy function is the same as it can be used in many different ways and for many different purposes depending on where it is used and who uses it. Here are some examples:
If two parties want to write or talk to each other but not speaking the same computer language can allow a proxy to translate communication. This works much like a simultaneous interpreter fixed for different data protocols.
To surf "anonymous", that is without talking about its IP address, the user can configure their browser to connect through a proxy. Such proxy works the same as a company proxy but is out on the Internet instead of on the local network. It is then the proxy's IP address as seen and recorded in log files on the server to connect to. Completely anonymous becomes one may not, for even if the target server can not see the real IP address so it can still be stored in log files on the proxy server or the routers the traffic passes out on the Internet. On suspicion of crimes can the police come to request access to the log files from these servers. So-called anonymizers intended for anonymous surfing normally stores no data about the user.
Another use for an open proxy is to bypass a Web filter in a different proxy. Although the administrator in an enterprise network appreciate the opportunity to filter the pages of a proxy server so it is not certain that users will find themselves in these restrictions. If the filters available in the proxy blocks the addresses of some websites but not blocking the address of an open proxy, so the user can access the content on the pages anyway by setting your browser to use the open proxy server. There are also online services that do the same by filling in the address to a Web page on their website. An example of a web page that can be used as the translation service, Babel Fish on altavista.com.
When using a proxy (eg an anonymising HTTP proxy), all data sent to the services used (such as websites) to pass through the proxy server before it is sent on to the service, mostly in unencrypted form. It is therefore both possible and appropriate to a malicious proxy server saves information about what passes, including, for example, username and password.
By linking proxies that do not reveal data on the origin user, it is possible to hide activities from the final destination. But the track will remain on the intermediate jumps, which may be used to track user activities. If the terms and administrators at the intermediate proxierna is unknown, the user can therefore fall prey to a false sense of security.
It is also common for proxy users find themselves blocked from some sites, this because forums and websites blocking IP addresses from proxies that they have had problems with spam from.