What Is a Reverse Proxy Server?

With every extensive, distributed network, several types of servers are in play, such as web, email, file, and FTP, often relying on protocols like the Server Message Block Protocol (SMB) for efficient file sharing and communication. There are several types of proxy servers; two prominent proxies are a forward proxy server (tunnel or gateway) and a reverse proxy.

A proxy server is an intermediary between a client seeking a resource and a server that provides the resource. In simpler terms, a proxy is an application (or server) that sits between someone clicking on a website to buy cookies and the website taking the order and shipping gooey chocolate cookies.

Proxies give personal and commercial users several advantages on distributed networks, the most significant being security. Proxies are commonplace when accessing the internet from a home computer or desktop at work. A valuable layer of security is created when web requests are routed through a proxy.

For a business, proxies offer multiple benefits:

• Internet Security is improved
• Employees are secure from malicious internet activity
• Load balancing internet traffic
• Employees and staff activities are controlled
• Caching and compressing internet traffic requests

What Is a Reverse Proxy Server and How It Works?

Forward proxies are positioned in front of consumers or clients, securing internet traffic on internal networks. At the other end of the scale is a reverse proxy, positioned in front of web servers sending and receiving requests from the origin server. Reverse proxies are effective options for popular websites needing to load balance internet traffic, reduce bandwidth, and provide security.

Reverse proxies can be integral to an organization’s security footprint, positioned between web servers and clients. Reverse proxies ensure that no client, regardless of where they are on the network or who owns the website, has the ability to communicate with the origin server. Forward proxies are focused on managing messages and content for the client, whereas a reverse proxy application is focused on vetting content for the origin server.

Reverse proxies provide an extra layer of control and abstraction on the network, ensuring the smooth content flow between clients and servers.

What's the Difference Between Forward Proxy and Reverse Proxy?

A reverse proxy and forward proxy both serve a common mission in enterprise architectures: to facilitate requests for resources between private networks and the public internet. However, they perform drastically different functions and serve decidedly different clients.

The key difference between a reverse proxy and a forward proxy is that a forward proxy enables computers isolated on a private network to connect to the public internet, while a reverse proxy enables computers on the internet to access a private subnet.

Forward proxies help users on private subnets access the public internet. A reverse proxy enables requests that come from the public internet to access resources that reside on an otherwise private subnet.

What Are the Benefits of a Reverse Proxy Server?

• Activity Monitoring and Logging help an IT team to manage where client requests are received and how the origin server responds to each request. With detailed information from the reverse proxy, teams can see how each site handles requests. Performance statistics by date and time can be analyzed to see if site infrastructure is up to the task.
• Caching is vital for reverse proxies to help load content faster because the cache is immediately available to clients and hosts. Content requests are handled solely by a backend server without a reverse proxy. 
• Load Balancing by a reverse proxy distributes incoming content requests so it is delivered to the client quicker. The reverse proxy helps to decide how to route HTTP sessions. The proxy helps origin servers from being overworked by limiting the number of network bottlenecks. Reverse proxies act as traffic cops sitting in front of backend servers distributing client requests across a group of network servers. Load balancing produces a more efficient and valuable network.
• Web acceleration is accomplished with a well-configured reverse proxy by compressing inbound and outbound data speeding the traffic flow.  
• Security is a fundamental function of reverse proxies in that admins can hide an origin server’s IP address. Hackers cannot directly target origin servers from malicious actors. Reverse proxies can be set up to detect malicious attacks such as DDoS and other harmful content.
• SSL Encryption can be costly due to the large amount of content streaming in and out of an origin server. However, all SSL Encryption can be run through a reverse proxy. 

Implementing a reverse proxy begins with rules and knowing precisely what the proxy will be used for. Ensure the reverse proxy and your site are hosted on the same server. A system admin will take the objectives and rules to configure the proxy. Rules give the proxy design and implementation instructions on what to do in specific situations. 

What Are the Disadvantages of Implementing a Reverse Proxy?

Even though a reverse proxy effectively improves network performance, the application has some disadvantages.

• Increased complexity is added to an already complex network. Reverse proxies require additional configuration and maintenance, making the application challenging to troubleshoot. The reverse proxy requires costly additional resources such as network CPU and memory.
•  A reverse proxy must be configured correctly to ensure no new vulnerabilities are introduced to the system. The proxy makes it difficult to scale a network system and handle additional loads. Reverse proxies must handle additional content requests without adding latency to an overworked network.
• Lack of flexibility is added to a network by implementing a reverse proxy because the server must be explicitly configured to a group of tasks. These tasks will be hard to handle if outside the scope of the proxy. Additional processing, such as authentication and encryption, will be limited.
• Implementing a reverse proxy to a distributed network adds significant additional costs, such as hardware and software required to run the proxy. Maintaining a reverse proxy can be hard to sustain, requiring added time and personnel resources. 
• The increased latency is introduced to the system because of additional processing and response time with forwarding the content to an origin server. If the content is sent through a reverse proxy with low latency, this can be a problem with applications that require real-time processing. Additional configuration is required to account for low latency correctly.
• Additional security risks are added to a network with a reverse proxy. Proxies must be configured correctly to ensure that it is not adding any vulnerabilities to an overworked system. Additional resources are required to monitor the server against attack.

When to Use VPN and Reverse Proxy?

The general rule of thumb for a network admin is to use a VPN if internet traffic needs to be encrypted. If the content only needs rerouting or enforcement of restrictions, then a reverse proxy is the best bet. Plus, a reverse proxy will be more cost-effective in most instances. If the content is threatened, a reverse proxy can act as a firewall to correctly protect incoming requests and routing.