What best practice should organizations follow regarding their firewall rules?

The best practice for organizations regarding their firewall rules is to regularly remove unused entries. Firewall rules are critical components of a network’s security posture, as they dictate what traffic is allowed or denied. Over time, as networks evolve, certain rules may become obsolete or irrelevant due to changes in business processes, application usage, or infrastructure updates.

By regularly removing unused entries, organizations can minimize the attack surface, reduce the potential for misconfigurations, and enhance overall firewall performance. Unused rules can lead to confusion and unnecessary complexity in rule management, making it easier for security vulnerabilities to go unnoticed. Keeping the ruleset clean and relevant allows for better monitoring and quicker responses to threats, ensuring that the firewall operates efficiently and effectively blocks unauthorized access.

Reviewing firewall rules annually or updating them monthly doesn't specifically address the need to maintain a streamlined and effective rule set. Similarly, only reviewing rules after an incident can lead to reactive rather than proactive security measures, which may not adequately protect the organization from various threats. Removing unused entries regularly is a proactive approach that enhances security and simplifies rule management.