To serve and protect: forward vs reverse proxy.

Julia Smith
Julia Smith
Community manager @ SOAX07 April, 2022

Forward and reverse proxies look similar and the difference between the two types of proxies is subtle, it’s crucial to distinguish them. Both function as a mediator between a client and the Internet, but they stand on the opposite sides of the client-server connection.

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Proxy is a service that operates on behalf of another machine; hence it works as a middleman. It mediates online connections, traffic, and user requests to websites and web apps, and it can be used for different purposes. It does not only widen the opportunities for business growth. It also routes and secures traffic between networks and clients’ requests. Proxy is a general term for different services and protocols that act as described above. No wonder there are different types of proxies. Some define the range of privacy; others manage the client’s access to the web, still, others specify what device acts as a proxy. It is important to understand how they work and differentiate between them. There is a type of proxy that determines the client-server relationships. 

When speaking of a proxy, we refer to safe access to the web. A proxy that determines the relationship between a client and the external web is usually called a forward proxy. It operates between a client and any server it connects with, and among other uses it sets for a client’s protection

A forward proxy is used in the internal network by a client — a user or a web browser — usually to bypass firewall restrictions in order to visit the websites that are blocked or to gain an easy access to data so as to parse it

And here, we have got a reverse proxy that protects not a client but a server. This type of proxy can be referred to as a reverse proxy. It controls access to the original server on a private network. 

Not only a client wants to have safe access to the web. The Web server also does not know who addresses it: a client or malware. When there are millions of requests to the web server, the desire to hide its location and ensure anonymity is reasonable. 

A reverse proxy is also used by different businesses, but it provides anonymity and security for backend server(s), not clients. It also serves as a load balancer and in some other cases it improves the website performance.

A reverse proxy is useful when there is one server. If there is a group of web servers, a reverse proxy can act as a perfect load balancer. Sites with over a million visitors per day generally have many servers. And a reverse proxy can evenly distribute the oncoming traffic between them, so they run faster and without breakdowns.   

What is a forward proxy?

When people speak of “a proxy”, they refer to a forward proxy. The main goal of a forward proxy is to connect and regulate the traffic between a client in the internal network and the Internet.

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As a forward proxy sits in front of a client, the request goes through the proxy first and then reaches the target webpage. Retrieving all the desired data from the website it redirects it back to the requester. A proxy and not the client make the request to the web server. Hence it ensures its anonymity. A forward proxy will mask the original user’s IP address from a connection target. With that, a forward proxy helps a client unblock a website’s security protocols or a service it needs to have access to.

What is a reverse proxy?

As a forward proxy acts on behalf of a client, a reverse proxy does the opposite. It sits in front of the origin server(s) on a private network and sends clients’ requests to these servers defining if a request would or would not pass through. A reverse proxy protects web servers from attacks ensuring that no user ever communicates with the origin server. 

This way, it controls access to a backend server, helping to increase its security and hide its location. By blocking requests headed to the backend server, a reverse proxy protects its identities against hacker attacks; thus it serves as a filter to a web server or a group of servers. Most clients do not even know that they address a reverse proxy.

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The other practical purpose is a performance boost: a reverse proxy caches commonly requested content so the web server runs faster. Moreover, a reverse proxy ensures reliability by acting as load balancer. It distributes clients’ requests across a group of servers to maximize speed and targeted resource capacities ensuring that no one server is overloaded. If one server goes down the traffic would be redirected to the remaining servers. 

A reverse proxy can also decrypt and encrypt all incoming and outgoing SSL/TLS communications freeing up resources on the original server. 

Forward vs reverse proxies

Differences

Although it sounds similar and the difference between the two types of proxies is subtle, it’s crucial to distinguish them. Indeed both function as a mediator between a client and the Internet, but they stand on the opposite sides of the client-server connection. 

The forward proxy sits in front of a client and is used, ensuring that no original server ever communicates with it. The reverse proxy at the other end is an intermediate server that sits in front of a backend server and blocks the direct interaction with a client.

In other words, a forward proxy protects a client, whereas a reverse proxy protects a backend server. Besides, there is a difference in their usage. Forward proxies avoid blocking, access geo-restricted content, parse data for business purposes and many more. Whereas web servers use a reverse proxy to ensure additional safety from hacker attacks, avoid overloading, cache content, encrypt ssl/tls, etc.    

Similarities

In general, both types of proxy help increase security, improve performance and ensure reliability. Although they fulfil different tasks, the proxies, however:

  1. Process users’ requests and control web traffic.
  2. Allow or block access to a network. 
  3. Act as a single entry point for clients. 

What are forward proxies used for?

There are quite a few good reasons for single users or businesses to use a forward proxy:

1. It helps to bypass geo-restrictions

With a forward proxy, you will have access to the blocked site in the country. Now you can pass over any geo-restrictions and make it to the whole world! 

Furthermore, a forward proxy allows a user to see how the ads are visible from websites in different countries. This helps make certain adjustments to improve ads performance and boost sales. 

2. It masks the identity

A proxy masks the identity and location of a client by changing its IP address. The client does not communicate directly with the target source; it‘s the proxy that connects to it and transfers data back from the end server to the client.

3. It’s the best for web-scraping

The life of a business is web-scraping. A forward proxy is meant to overcome the web access limitation for collecting the client’s data to improve ads campaigns and marketing metrics, set competitive prices and elaborate business strategies. 

What are reverse proxies used for?

If a forward proxy makes it easy for a client, what use cases can be numbered for the reverse proxy? The capabilities are vast, and sometimes they are not so obvious. Let’s see why and how businesses can use a reverse proxy?

1. Load balancing

A popular website gets millions of users every day. A single server hardly handles incoming traffic without complete failure. Clients’ requests can be distributed evenly among different servers to prevent any single server from being overloaded. If that happens, a reverse proxy redirects traffic to another backend server in a private network.

2. Security

A reverse proxy hides the IP address of the original server and makes it harder for hackers to attack and deface it. Instead, DDoS attacks will be targeted only on a reverse proxy. Besides, a reverse proxy protects its identity by intercepting requests headed to the backend server. Your backend server stays secure and anonymous.

3. Speed

A reverse proxy server can cache content. It collects and temporarily saves the response data boosting traffic flow between a client and a server when similar requests occur. This will result in faster performance. 

On top of that, a reserve proxy can also decrypt all incoming requests and encrypt all outgoing responses and reduce the load on the web servers. It also authenticates and authorises requests, improving the website’s performance. 

The common idea is that a reverse proxy generally acts as a load-balancer, but it does more than that. It encrypts and decrypts SSL/TLS communications, cache content and authenticates clients. Using a reverse proxy, you can boost the website performance metrics and secure it from hacker attacks. 

In conclusion

Many businesses use proxy to control and secure traffic on the Internet. Both types of proxies – forward and reverse ones – are two different concepts of management control. Although similar (they help to interact between a client and the web), these are meant for different purposes: a forward proxy protects a client, whereas a reverse proxy protects the server ensuring the safety, control and smooth flow of network traffic.