• Web proxies
Web proxy is a commonly used proxy application. The file and web pages available on the remote web servers are provided through the nearby cache. In this way, local clients can access the information more reliably and quickly.
A web based proxy server looks for a URL in local cache when a specific web resource or URL is requested. The document is returned immediately if it is found on the local cache. In other cases, the server requests the page from the remote server and then returns it to the client and saves a copy in the cache. An expiry algorithm is used to delete the documents from the cache depending upon the access history, size and age. Least Frequently Used (LFU) and Least Recently Used (LRU) are the two expiry algorithms that are used in this case. Least frequently used documents are removed by LFU while the least recently used documents are removed by LRU.
CGI proxies are special web proxies. These are special types of websites that allows clients to access the desired site through them. In order to implement proxy, CGI or PHP are used.
The content of the web page is filtered in case of some web based proxy. Some may reformat the page while others may block inappropriate content displayed on the website. These types of servers can be implemented to intercept viruses and other content present on remote pages.
• Transparent Proxy Servers
Transparent Proxy reveals its identity and by using http headers, the original IP address can be made available. These servers have the ability to cache websites but they do not provide any anonymity. However, using transparent proxy may lead to simple IP bans.
• Distorting Proxy Servers
It reveals its identity as a proxy server but provides an incorrect IP address when requested through http headers.
• Anonymous Proxy Servers
Although it reveals its identity as a server but does not provide the original IP address. However, this type of server is detectable but it provides an ample amount of anonymity to clients.
• High Anonymity Proxy Servers
These types of servers do not reveal their identity. Moreover, they do not provide the original IP address as it gives an incorrect IP address through http headers. This explains the different types of proxies that can be used to hide the original IP address of a computer. However, it may not be beneficial in some cases as other devices contact to your computer through IP address only.