What Are the Famous Types of Proxy Servers?

A proxy server, also known as a proxy, WWW filter, or web filter, is a computer that sits between the user’s browser and the Internet. It observes all traffic passing in either direction and can perform various operations for different purposes. For example, the administrator might want to filter out dangerous websites by blocking requests or redirecting them to another site without informing the user. Although the administrator might want to block only a few sites, the administrator must keep in mind that filtering will make other users dissatisfied. 

Therefore, the administrator must select appropriate proxies useful for the user. The proxy server can also perform various operations on web traffic passing through it, such as logging traffic by IP address, IP address information by URL path information, URL information by IP address information, time information of transmission and access of website data, location information of the source and destination hosts connected to each site. For more information about the various types of Proxy Servers, you can look at this site to better understand. 

  • Forward Proxy –

The main function of a forward proxy is to provide a secure link on the Internet between the user and the server. Usually, there is a reverse proxy server and a forward proxy server. The first computer receives the request from the client and forwards it to the Internet server. The second computer can be called reverse-proxy, acting as an Internet security gateway, firewall, or application security layer.

The second computer inspects the contents of the request over the Internet and forwards it to the server only if the condition required for allowing this request is met. If the conditions are not met, the request is rejected. The client receives a response from an external server. Typically, forward proxies are used in web filtering setups where they are configured only to allow requests for websites that are allowed to be accessed by their organization.

  • Transparent Proxy –

Transparent proxies provide a way for an isolated internal network to safely use an external connection for Internet access. These proxies typically can be removed or modified without affecting the VPN. A transparent proxy is a network firewall application for web traffic. It can be used in conjunction with a dedicated web cache server or with content delivery networks to optimize content delivery over a WAN.

It can also provide a better experience for users attempting to access a web application located on a server that does not have a high-bandwidth connection. The transparent proxy is designed with an internet browser running on the client machine as its source. The transparent proxies use HTTP as their default protocol, so they need to support HTTP proxy and SSL traffic.

  • Reverse Proxy –

Reverse proxies are used to reverse the path that a web request takes. Reverse proxies are used with many different protocols, including HTTP, HTTPS, SMB, FTP and more. The reverse proxy is used instead of traditional proxying if the proxied application has an active request life cycle. For example, an application server with PHP or Java can sometimes execute some PHP or Java code to handle the HTTP request itself. 

A reverse proxy is also used when the web application is hosted on firewalled computers, but the client needs access to web applications. Reverse proxies are especially useful in handling load balancing across multiple servers, so clients are unaware of latency issues or server health issues. However, handling cookies by reverse proxies can be problematic because it has to be configured to forward all cookies, not just those for the proxied server(s).

  • STUN/TURN –

This public key-based, scalable and straightforward protocol provides a mechanism for a server to learn the IP address of a user making an outgoing TCP connection. It is designed to solve problems with NAT traversal while still having the option of being used in more controlled environments. 

It is accomplished by communicating information between STUN and TURN servers on both sides of the NAT device. When a connection is initiated from an external address, the intended recipient inside the private network knows approximately where to forward it. TURN is a set of extensions to STUN that enable media relay.  With TURN, a connection is relayed if the device the request is coming from cannot be used.

Recently, application-level proxies have gained importance in application acceleration and security services. Proxies help applications work better over the Internet. Such proxies include caching proxies, web accelerators or agents, firewall agents, security agents or gateways, etc.