Proxy Server Topics

• high anonymity proxy
• anonymizing proxy server
• high anonymity proxies
• relevant server
• proxy servers
• connection web
• individual systems
• freedom of speech
• remote server
• caches
• human rights
• principle
• protocol
• elite
• web page
• proxy client
• server proxy
• proxy service
• ip address
• traffic

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Proxy Server, Proxy Server

A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource, available from a different server. The proxy server evaluates the request according to its filtering rules. For example, it may filter traffic by IP address or protocol. If the request is validated by the filter, the proxy provides the resource by connecting to the relevant server and requesting the service on behalf of the client. A proxy server may optionally alter the client's request or the server's response, and sometimes it may serve the request without contacting the specified server. In this case, it 'caches' responses from the remote server, and returns subsequent requests for the same content directly.

An organization may have many systems on the same network or under control of a single server, prohibiting the possibility of an individual connection to the Internet for each system. In such a case, the individual systems can be connected to one proxy server, and the proxy server connected to the main server.

Some users are merely interested in anonymity on principle, to facilitate constitutional human rights of freedom of speech, for instance. The server receives requests from the anonymizing proxy server, and thus does not receive information about the end user's address. However, the requests are not anonymous to the anonymizing proxy server, and so a degree of trust is present between that server and the user. Many of them are funded through a continued advertising link to the user.

Other anonymizing proxy servers, known as elite or high anonymity proxies, only include the REMOTE_ADDR header with the IP address of the proxy server, making it appear that the proxy server is the client. A website could still suspect a proxy is being used if the client sends packets which include a cookie from a previous visit that did not use the high anonymity proxy server. Clearing cookies, and possibly the cache, would solve this problem.

This is often achieved by using a VPN type tunnel, such as VPN itself or SSH, through a port left open by the proxy server to be circumvented. Port 80 is almost always open to allow the use of HTTP, as is Port 443 to allow the use of HTTPS. Through the use of encryption, tunnelling to a remote proxy server, provided the remote proxy server is itself secure, is not only difficult to detect, but also difficult to intercept.

However, if one has access to a system with higher access rights, they could use that system as a proxy server for which the other clients use to access the original proxy server, consequently altering their access privileges.

If there is no choice but to use unknown proxy servers, do not pass any private information (unless it is over an encrypted connection) through the proxy.

Source: Wikipedia > Proxy Server