Which type of firewall only inspects packet headers for allowing or denying traffic?

The correct choice focuses on a Packet-Filtering Firewall, which functions by examining the header information of packets as they traverse the network. This includes evaluating information such as source and destination IP addresses, ports, and the protocol used. By analyzing these aspects, the firewall can make decisions to allow or deny traffic based solely on these criteria without considering the state of the connection, which is a distinguishing feature of more advanced firewalls.

Packet-filtering firewalls operate at the network layer of the OSI model and are generally considered simpler and faster than their stateful counterparts since they do not track the connection state or keep a session table. They work well for basic filtering tasks and are often used as a first line of defense in a network security strategy. However, this simplicity means they may not offer robust protection against more sophisticated attacks that exploit stateful behavior or application-layer vulnerabilities.