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All glossary terms

Proxy & networking

Firewall rule

A firewall rule is a condition and action used to control whether traffic is allowed, denied, or routed for another decision. In an application proxy, the rule can evaluate only the request attributes and connection details that the proxy can observe.

Also known as proxy rule.

Why it matters in practice

Rule order, default behavior, protocol visibility, and error handling affect the outcome of a policy. HTTPS requests hidden inside opaque CONNECT cannot be evaluated by application path unless the proxy inspects TLS. A set of rules should be tested against expected and unexpected requests; it is not automatically a complete SSRF defense.

Example

An administrator writes a rule that allows a specific request method for api.example.com and verifies that a different destination is handled as intended.

Educational note

This definition is general information, not legal advice. It may omit facts that matter to a specific situation and does not establish or guarantee compliance.