What kind of firewall makes decisions based both on predefined rules and the state of active connections?

A stateful firewall is designed to monitor the state of active connections and make decisions based on predefined rules as well as the context of the traffic associated with those connections. Unlike stateless firewalls, which evaluate each packet in isolation based solely on set rules, stateful firewalls maintain a record of active sessions and are able to understand the state and characteristics of those connections.

This means they can assess whether incoming packets are part of an established session or if they are new connection attempts. As a result, stateful firewalls offer enhanced security features compared to their stateless counterparts, making them better suited to handle complex applications and protocols that involve multiple packets and sessions.

In contrast, proxy firewalls act as intermediaries for data traffic without maintaining stateful information about connections, while hybrid firewalls combine features of both stateful and stateless firewalls but are not specifically defined by the core principle of stateful tracking.