What is a Proxy Server

A proxy server is an intermediary computer that is between the user’s computer and the Internet. It can be used to log Internet usage and also to block access to a website. The firewall at the proxy server blocks some websites or web pages for various reasons. More specifically, a proxy server, also known as a “proxy” or “application level gateway”, is a computer that acts as a gateway between a local network (e.g., all the computers at one company or in one building) and a larger-scale network such as the Internet. Proxy servers provide increased performance and security. In some cases, they monitor employees’ use of outside resources.

Do not confuse a proxy server with a NAT (Network Address Translation) device. A proxy serverconnects to, responds to, and receives traffic from the Internet, acting on behalf of the client computer, while a NAT device transparently changes the origination address of traffic coming through it before passing it to the Internet.

If you want to surf the web anonymously then proxies can provide you with a means to hide your home IP address from the rest of the world. By connecting to the internet through proxies, the home IP address of your machine will not be shown but rather the IP of the proxy server will be shown. This can provide you with more privacy then if you were simply connecting directly to the internet. There are number of proxies that can provide you with service. You can find a list of these simply by typing “Proxy List” into any search engine. There are some proxies that are free and some which charge money, the choice is up to you but it has been found that the paid proxies are more reliable, faster and more secure.

A typical setting of proxy on your computer for a FireFox browser is as under:

  • Click the FireFox Button(The button in the upper left corner)
  • Click Options
  • Click Options in the new tab
  • Click the Advanced Tab
  • Click Settings
  • Click Manual Proxy Settings
  • In the HTTP Proxy Box enter the IP Address of the proxy server and the Port number
  • Click OK
  • Go to to check for proxy

If your proxy is setup correctly you will see its IP address on the homepage and you may receive a message that a proxy was detected. It is impossible to detect all proxies. Some proxy serversimplement a logon requirement. In large organizations, authorized users must log on to gain access to the web. The organization can thereby track usage to individuals.

Proxies may also cache web pages. Each time an internal user requests a URL from outside, a temporary copy is stored locally. The next time an internal user requests the same URL, the proxycan serve the local copy instead of retrieving the original across the network, improving performance.

A proxy that focuses on WWW traffic is called a “web proxy“. The most common use of a webproxy is to serve as a web cache. Most proxy programs (e.g. Squid) provide a means to deny access to certain URLs in a blacklist, thus providing content filtering. This is usually used in a corporate environment, though with the increasing use of Linux in small businesses and homes, this function is no longer confined to large corporations. Some web proxies reformat web pages for a specific purpose or audience (e.g., cell phones and PDAs).

An anonymous proxy server (sometimes called a web proxy) generally attempts to provide anonymous web surfing. These can easily be overridden by site administrators, and thus rendered useless in some cases. There are different varieties of such anonymous experiences you may encounter via the use of a proxy. One of the more common variations is the open proxy. Because they are typically difficult to track, open proxies are especially useful to those seeking online anonymity, from political dissidents to computer criminals.

Some typical functions of a proxy server includes:

1. It reduces the time needed to access resources from servers by serving cached responses for similar request to clients.
2. It serves a log to provide information on internet usage for auditing or evaluation purposes.
3. It could be used to over-ride security or parental control
4. It enables access to regionally restricted resources
5. It hides its clients for anonymous browsing and security
6. It could be used to block access to unwanted or unauthorised sites
7. It serves as a scan to filter malware before delivering requested resources
8. It serves as a scan to block certain outgoing data. This is for protected files

Since it is an intermediary that acts on behalf of two or more users or clients, a proxy server can be placed anywhere in-between the users or at destination servers on the internet for it to serve its functions.