Which of the following is a typical firewall capability?

• A. Encrypts data at rest
• B. Filtering services and packets
• C. Generating digital certificates
• D. Providing single sign-on

Answer: (B)

Firewalls are designed to control network access by inspecting and enforcing rules on the traffic that traverses them. A typical firewall capability is filtering services and packets, meaning it can allow or block traffic based on criteria such as source and destination IP addresses, ports, protocols, and even application characteristics. This filtering is what lets the firewall enforce security policies, block malicious or unwanted communications, and permit legitimate services to function.

Encrypting data at rest protects stored data on disk, which is a data protection function rather than a firewall task. Generating digital certificates relates to establishing trusted identities and secure key exchange, usually handled by PKI systems. Providing single sign-on is about user authentication across systems, which belongs to identity and access management.