Proxying

Proxying is the practice of routing network requests through a proxy server or service so that the request to the origin resource appears to come from the proxy rather than the client. Proxies act as intermediaries between clients and servers, and can be configured for various purposes, including performance, security, and access control.

Proxies are commonly categorized as forward proxies, which act on behalf of clients to retrieve resources from the internet; reverse proxies, which act on behalf of servers to handle requests from clients; and other variants such as transparent proxies, anonymous proxies, open proxies, and SOCKS proxies. Each type serves different architectural goals and deployment scenarios.

How proxying works: a client directs traffic to the proxy, which then forwards the request to the destination server. The destination’s response travels back through the proxy to the client. Proxies can provide caching to reduce latency, enforce security policies, and distribute load among multiple backend servers. With TLS, proxies may terminate or pass through encryption depending on configuration; some deployments employ TLS inspection, which can expose contents to the proxy if configured to decrypt traffic.

Common use cases include enhancing privacy or anonymity, bypassing geographic or content restrictions, and enforcing corporate security policies. Reverse proxies are widely used by content delivery networks and web services to balance load, terminate TLS, and shield origin servers.

Advantages include improved performance, centralized control, and enhanced security. Drawbacks include added latency, reliance on the proxy operator, potential misconfiguration, and privacy concerns. Proxying differs from VPNs in that proxies typically operate at the application level and may only route specific traffic, whereas VPNs aim to tunnel all traffic from a device. Legal and ethical considerations apply when using proxies to circumvent restrictions or monitoring.