Reverse Proxy vs. Forward Proxy: The Differences

What is a proxy server? 

A proxy server sometimes referred to as a forward proxy, is a server that routes traffic between the client(s) and another system, usually external to the network. 

By doing so, it can regulate traffic according to preset policies, convert and mask client IP addresses, enforce security protocols, and block unknown traffic.

Systems with shared networks, such as business organizations or data centers, often use proxy servers. 

Proxy servers expose a single interface with which clients interact without having to enforce all of the policies and route management logic within the clients themselves.

What is a reverse proxy?

A reverse proxy is a type of proxy server.  Unlike a traditional proxy server, which is used to protect clients, a reverse proxy is used to protect servers. 

A reverse proxy is a server that accepts a request from a client, forwards the request to another one of many other servers, and returns the results from the server that actually processed the request to the client as if the proxy server had processed the request itself. 

The client only communicates directly with the reverse proxy server and it does not know that some other server actually processed its request

Types of reverse proxies

In their functionality, all reverse proxies are more or less the same. However, we can distinguish two main types of reverse proxies based on their features. They are regular reverse proxies as such and load balancers. 

1. Regular reverse proxies. This proxy type intercepts the request from a client, directs it to the server to process it, and then sends it back to the client. This proxy type is mainly used for security purposes. 

2. Load balancers. This proxy is a reverse proxy subtype that leads to multiple backend instances instead of one.It is capable of distributing the traffic among multiple other servers and managing client-server communication between all of them. 

This type is more specifically tailored to distribute the load evenly among different servers, thus increasing the speed and performance.

What are reverse proxies used for?

Websites and service providers may use reverse proxies for different reasons, and here are some of them:

1. Load balancing. Frequently visited websites may sometimes need reverse proxy servers to deal with the flow of incoming traffic. Instead of handling it on its own, a popular site may distribute the traffic between multiple back-end servers and thus boost its capacity for handling many requests. 

If one of the servers is overloaded and out of order, the traffic can be redirected to other online servers keeping the web page running. 

The website engineers may even add more back-end servers to this load balancer to increase capacity and meet rising demand for performance.

2. Caching. A reverse proxy is capable of caching data that is commonly requested. Businesses that store a lot of pictures and videos may also speed up the performance of their websites by caching this content and reducing the load on the internet servers. 

3. Anonymity and security. Since reverse proxies intercept all the incoming requests,  they serve as an additional level of protection for backend servers. It helps prevent any malicious actors from abusing web servers by blocking suspicious traffic from specific IP addresses.

There are many reverse proxy software such as:

1. Nginx can act as a web server and a reverse proxy at the same time. 
2. Apache can act as a web server and a reverse proxy at the same time. 
3. HAProxy is a well-known, feature-rich, and open-source reverse proxy software.

Forward proxy vs reverse proxy

1. Differences

The key difference between a forward proxy and a reverse proxy is that the first one is used by a client, e.g., a user inside a private network, while the second one is used by an internet server. 

A forward proxy can be positioned in the private network together with the user, or it can be online.

2. Similarities
In essence, forward and reverse proxy services are meant for different tasks but they both:

1. Handle client requests and mediate web traffic.
2. Authorize or block access to a service.
3. Act as a single access point for either devices or servers.

3. Forward proxies: common use cases

There are quite a good few reasons why single users or businesses use forward proxy servers:

1. A remedy for geo-restrictions

First and foremost, a forward proxy will let you enjoy no geo-blocks and avoid country restrictions. Forget about the great firewall of China or other blocked resources anywhere in the world!

When using a forward proxy, users can access the content intended for other countries. For example, imagine you need to see if your ads are visible in Canada. Just use a Canada proxy and access content in Canada. Simple, right?

2. Anonymity

A forward proxy hides the identity and location of the original client by changing their IP address with that of the proxy. It's actually the proxy that connects to the end server.

3. Web scraping

The most common use of proxies is web scraping. To stay competitive, a company needs to collect information from various resources to improve its social media campaigns, marketing, pricing, and other business strategies.

4. Reverse proxies: common use cases

Reverse proxy capabilities are enormous. There's a bunch of reasons why (and how) businesses use reverse proxy servers, but let us give you three key ones:

1. Load balancing

These days, web traffic is heavy! Just imagine all those millions of visitor requests hitting websites every second. If you have only one server, your internet site might not handle all incoming network traffic. 

This is why it's vital to distribute traffic among a group of backend servers that all handle client requests for the same website.

A reverse proxy can provide excellent load balancing solutions, equally distributing incoming traffic between different servers. This way, servers stay protected from being overwhelmed by multiple requests at the same time. If there's a point of failure at one server, the other servers can handle the traffic as well.

2. Security

The reverse proxy server blocks requests from being sent to a backend server. A website, which uses a reverse proxy server, will never reveal the IP addresses of the origin server, which makes it difficult to execute attacks.

Besides, if you're a server owner, you can use reverse proxies to hide the rest of your servers behind a firewall that is only accessible with the help of the reverse proxy. This way, your servers stay even more secure and anonymous.

3. Speed

A reverse proxy server can compact incoming and outgoing data and cache frequently requested content. If you do both, this will boost the flow of traffic between the client and the server.

On top of that, reserve proxy servers can also perform some additional tasks, such as SSL encryption or HTTP access authentication, which reduces the load on your web servers. What's the result of that? Your website performance improves!