Proxy Server

A proxy server is a special type of computer server used to make an Internet connection from certain computers. Even though proxy servers are an old technology, they are still used in organizations because of their usefulness in regulating what goes in and out of a corporate network.

A proxy server is located between the computer that wants to have Internet access and the Internet connection. If a computer in the network wants to access the Internet to, for example, go to the Web page Yahoo.com, it sends a request for the page to the proxy server. The proxy server then looks at its hard disk drive to see if it already has the requested material. If it does, it sends the page to the computer. If it doesn’t, it connects to the Internet, requests the Web page from Yahoo's server, and forwards it to the computer.

Some of the benefits of using a proxy server for companies are:

• All transactions pass through the proxy server and can be monitored and controlled by the company.
• Attackers trying to reach internal computers will only get to the proxy server.
• If the proxy server stores all requests and responses from connections, then it can deliver pages more quickly than if it had to connect the computer directly with the destination.
• There are many third-party vendors and application providers that offer products for checking the connection. Some examples are Websense Enterprise , which can control the type of web pages employees may surf, and Trend Micro InterScan , which can clean out viruses and malware.

One disadvantage of proxy servers is that they can typically be used only for web surfing, email and some file transfers. Custom network applications that use non-traditional ports for communication must rely on a special type of proxy server called Proxy SOCKS.