What type of firewall filters traffic based on connection state?

A stateful firewall is designed to filter traffic based on the connection state, meaning it keeps track of active connections and determines whether a packet is part of an existing connection or a new request. This allows the firewall to make more informed decisions about which packets to allow or deny based on the context of the transmission.

Unlike stateless firewalls, which analyze packets in isolation without considering the state of the connection, stateful firewalls evaluate the state of a connection and can recognize packet sequences, thus providing enhanced security. They maintain a state table that stores information about active sessions, enabling them to permit or block packers based on set rules and the context of the entire session.

Application-layer firewalls operate at a higher level, inspecting the payload of the packets rather than focusing on the connection state, while packet filtering firewalls check packets against a set of predetermined rules but do so without maintaining information about connection states. The capabilities of stateful firewalls make them more effective at handling various types of network traffic and enhancing overall security.