Cisco Cyber Security Practice Exam

What type of firewall inspects outgoing traffic and monitors the establishment of connections before permitting related traffic?

1. Stateless firewall

2. Content-filtering firewall

3. Stateful firewall

4. Next-generation firewall (NGFW)

The correct answer is: Stateful firewall

A stateful firewall is designed to inspect outgoing traffic and monitor the establishment of connections, maintaining a state table that keeps track of the state of active connections. This allows the firewall to determine whether incoming traffic is part of an already established connection, thereby enabling it to permit or deny traffic based on the context of the connection rather than simply on the packet level. This connection tracking feature allows stateful firewalls to provide a more sophisticated level of security compared to stateless firewalls, which do not keep track of the state of connections and only inspect packets in isolation. While next-generation firewalls also offer advanced capabilities, such as intrusion prevention and application awareness, the fundamental characteristic being described—involvement with connection states—aligns specifically with stateful firewalls. Content-filtering firewalls, on the other hand, focus on inspecting the content of traffic rather than the state of the connections. Thus, the ability of a stateful firewall to monitor and inspect traffic throughout the life cycle of a connection justifies its selection as the correct answer for this question.