Cisco Cyber Security Practice Exam 2025 – Your All-in-One Guide to Exam Success!

A firewall's primary function is to monitor and control incoming and outgoing network traffic based on predetermined security rules. By examining packets of data as they attempt to enter or exit a network, firewalls can block or allow traffic based on specific criteria, thus protecting the network from unauthorized access and potential threats. This capability is essential for safeguarding sensitive information and maintaining the overall integrity of the network.

In contrast, physical security of servers is related to protecting the hardware from physical threats, which does not involve the network traffic management that a firewall provides. Managing user passwords pertains more to identity and access management rather than traffic control. Conducting data backups is focused on data recovery and integrity, which is a separate function entirely. Therefore, the monitoring and controlling of network traffic is the defining characteristic that identifies a firewall’s role in network security.