Proxy and Reverse Proxy Servers

Proxy Server

Proxy server is a computer system or application which works as an intermediary for clients searching resources which exist on other servers. It allows different users to access the internet at the same time on a single Internet connection. It aims to improve the speed of surfing the internet and reducing network traffic. It receives requests from a web user such as a web page or a file available on a different server, then it evaluates at responds to the request. It simplifies this process and controls it. A proxy server is also part of a firewall and helps to prevent hackers from using the internet in order to not let them gain access to computers on a private network.

The main features of a proxy server are:

  1. Caching: This happens when a user requests for a file. The proxy first browses its cache and forwards it if present; otherwise it forwards the request to the web server.
  2. Connection sharing: Proxies facilitate users to share the internet connection by configuring them to access the web through it instead of providing a direct link to each user.
  3. Filtering: Since the proxy servers handle all the users requests, it can therefore be used to restrict certain URLs.
  4. Security: The proxy server assists in security by hiding the IP address of the users.
  5. Scanning traffic: Sometimes proxies integrate with open source anti-virus software to scan the network traffic for viruses and worms.
  6. Bandwidth Control: The proxies use delay pools to control bandwidth by allocating specific bandwidth to internet traffic. This helps prioritise traffic thus reducing the network overload.

Reverse Proxy Server

A reverse proxy server is a server similar to a normal proxy server but it is located at the edge of the fire wall. This reverse proxy has its own external IP address on the external NIC and usually links it to one of the internal IP addresses. Reverse proxy’s main aim is to shield the public users from directly accessing the web server by only accessing the reverse proxy server. The reverse Proxy server actually Places HTTP data on the network and forwards it to the users web server. The internal firewall is configured in such a way that the HTTPS data will be forwarded through the internal firewall only if it is sent from the reverse proxy server. The web server then accepts the request, processes it and sends a response back to the reverse proxy server which in turn sends the requested date back to the originating client. This setup prevents public users from contacting the web server directly for security reasons.