A reverse proxy is a device or service placed between a client and a server in a network infrastructure. Incoming requests are handled by the proxy, which interacts on behalf of the client with the desired server or service residing on the server. The most common use of a reverse proxy is to provide load balancing for web applications and APIs. Reverse proxies can also be deployed to offload services from applications as a way to improve performance through SSL acceleration, intelligent compression, and caching. They can also enable federated security services for multiple applications.
A reverse proxy may act either as a simple forwarding service or actively participate in the exchange between client and server. When the proxy treats the client and server as separate entities by implementing dual network stacks, it is called a full proxy. A full reverse proxy is capable of intercepting, inspecting, and interacting with requests and responses. Interacting with requests and responses enables more advanced traffic management services such as application layer security, web acceleration, page routing, and secure remote access.
A reverse proxy is most commonly used to provide load balancing services for scalability and availability. Increasingly, reverse proxies are also used as a strategic point in the network to enforce web application security through web application firewalls, application delivery firewalls, and deep content inspection to mitigate data leaks.
A reverse proxy also provides the ability to direct requests based on a wide variety of parameters such as user device, location, network conditions, and even the time of day. When combined with cloud, a reverse proxy can enable cloud bursting and split-application architectures that offer the economic benefits of cloud without compromising control or security.
The F5 BIG-IP system is a full proxy that can be deployed to provide basic and advanced application network services, including load balancing, web performance optimization, application delivery firewall, and secure remote access.