Proxy Server

Forward vs. Reverse Proxies

A forward proxy sits between clients and external servers, forwarding client requests on their behalf. Clients are configured to send requests to the proxy rather than directly to the destination. Uses include web filtering in corporate environments, caching frequently accessed content, and anonymizing client IP addresses. From the server's perspective, all requests appear to originate from the proxy.

A reverse proxy sits between external clients and internal servers. Clients connect to the reverse proxy thinking they are connecting directly to the origin. The proxy forwards requests to appropriate backend servers based on routing rules. Nginx and HAProxy are common reverse proxy implementations. Reverse proxies provide load balancing, SSL termination, caching, and protection of backend server identities.

Transparent vs. Explicit Proxies

An explicit proxy requires client configuration — the browser or application must be told the proxy's address and port. A transparent proxy intercepts traffic at the network level without client awareness. ISPs sometimes deploy transparent proxies for caching or content filtering without user knowledge.

Proxy Chains and Privacy

SOCKS ProxyA general-purpose proxy protocol (SOCKS4/SOCKS5) that relays any TCP (and optionally UDP) traffic through a proxy server. Unlike HTTP proxies, SOCKS operates at a lower level and is protocol-agnostic. proxies operate at the transport layer, supporting any TCP or UDP protocol without protocol-specific handling. Chaining multiple proxies can increase anonymity, though each hop reduces performance and adds trust dependencies. TorThe Onion Router. An anonymity network that routes traffic through multiple encrypted relays (typically three) worldwide, making it extremely difficult to trace the origin of a connection. The basis of .onion hidden services. automates multi-hop proxy chaining with cryptographic layering for stronger anonymity guarantees.

Use IP Lookup to verify your apparent IP address when using a proxy, and DNS Leak Test to check whether DNS queries are bypassing the proxy and leaking your ISP's resolver.