What is a firewall rule?

What is a firewall rule?

• A. A rule that encrypts data
• B. A rule that deletes files
• C. A firewall rule defines whether to allow or block traffic; example: allow outgoing HTTPS and block all other inbound connections by default
• D. A rule that backs up data

Answer: (C)

A firewall rule is a setting that determines whether network traffic is allowed or blocked. Each rule specifies what traffic it applies to—such as the direction (incoming or outgoing), the protocol, the ports, and the source or destination IPs—and assigns an action like allow or block. For example, a rule that allows outgoing HTTPS traffic permits connections to port 443 using the TCP protocol, while a policy might block all other inbound connections by default to reduce exposure. This combination of defining what traffic matches and what to do with it is what lets a firewall control access to a network. The other options describe functions handled by other parts of a system—encryption protects data, deleting files removes data, and backups copy data for recovery—not how a firewall governs network traffic.

A firewall rule is a setting that determines whether network traffic is allowed or blocked. Each rule specifies what traffic it applies to—such as the direction (incoming or outgoing), the protocol, the ports, and the source or destination IPs—and assigns an action like allow or block. For example, a rule that allows outgoing HTTPS traffic permits connections to port 443 using the TCP protocol, while a policy might block all other inbound connections by default to reduce exposure. This combination of defining what traffic matches and what to do with it is what lets a firewall control access to a network. The other options describe functions handled by other parts of a system—encryption protects data, deleting files removes data, and backups copy data for recovery—not how a firewall governs network traffic.