A reverse proxy is a server or software application that sits between clients and backend servers, intercepting client requests and forwarding them to the appropriate backend servers. Unlike a traditional forward proxy that handles outbound client requests, a reverse proxy manages inbound client requests on behalf of backend servers. It acts as an intermediary that enhances security, improves performance, and provides additional features such as load balancing, SSL termination, caching, and web application firewall (WAF) protections.
Reverse proxies are used extensively in web hosting, application delivery, and security architectures. They serve several key purposes, including:
- Load Balancing: Distributing incoming client requests across multiple backend servers to optimize resource utilization and improve application performance.
- SSL Termination: Decrypting SSL/TLS encrypted traffic at the reverse proxy before forwarding it to backend servers, reducing the computational load on backend resources.
- Caching: Storing frequently accessed content at the edge of the network to reduce response times and lower server load.
- Security: Acting as a shield between clients and backend servers, protecting against attacks such as DDoS (Distributed Denial of Service) and providing a centralized point for implementing security policies like access control and WAF rules.
A reverse proxy is not the same as a Virtual Private Network (VPN). While both technologies involve intermediary servers, they serve different purposes. A reverse proxy manages and optimizes traffic between clients and backend servers, focusing on performance enhancement and security for server-side applications. In contrast, a VPN establishes a secure, encrypted tunnel between a client device and a remote server, encrypting all traffic passing through it to protect privacy and ensure data integrity.
NGINX is often referred to as a reverse proxy because it excels in handling inbound client requests and efficiently forwarding them to backend servers. Originally designed as a high-performance web server, NGINX has evolved to include robust reverse proxy capabilities. It is renowned for its ability to handle large volumes of concurrent connections, perform load balancing across backend servers, and manage SSL/TLS termination effectively. NGINX’s architecture and features make it a popular choice for enhancing the performance, scalability, and security of web applications and services deployed in diverse environments.