After a change to the firewall policy, which practice is recommended?

• A. Immediately update logs and ignore testing
• B. Reboot device and apply
• C. Do nothing
• D. Run vulnerability testing

Answer: (D)

After a firewall policy change, you need to verify that the new rules actually protect the network and don’t introduce new weaknesses. Running vulnerability testing examines how the updated policy behaves from an attacker’s perspective, uncovering misconfigurations, exposed services, open ports, or bypass paths that could be exploited. It helps confirm that only the intended traffic is allowed and that the change doesn’t create gaps in security. This proactive validation is far more effective than just logging, rebooting the device, or doing nothing, because it provides concrete evidence of the policy’s security posture and guides remediation before deployment. In practice, pair vulnerability testing with functional checks and change-control processes to ensure both security and reliability.