Transparent Proxy

A proxy that intercepts and redirects network traffic without requiring any client configuration — the client is unaware that a proxy is present. Transparent proxies are implemented using network-level traffic redirection, typically via iptables REDIRECT rules, WCCP with Cisco hardware, or policy-based routing. ISPs use them for bandwidth caching and traffic shaping; enterprises use them for security inspection. They cannot intercept HTTPS without performing TLS interception (MITM with a trusted corporate CA), which raises both security and privacy considerations.