How Often Should a Business Firewall Be Reviewed?

Why firewall configurations need regular attention

A firewall may continue passing traffic while its security posture gradually weakens. Temporary rules can become permanent, unused VPN accounts can remain active, firmware can fall behind and administrative access may be broader than intended.

Regular review helps confirm that the firewall still matches the current business environment. The goal is not simply to prove that the device is online; it is to confirm that access is necessary, controlled, documented and monitored.

Events that should trigger an immediate review

A new office, branch, internet connection or major network redesign.

Deployment of a new server, cloud service, public application or VPN.

Employees, administrators or service providers leaving or changing roles.

A security incident, suspicious login, malware alert or unexpected traffic pattern.

Replacement of switches, wireless systems or other important network equipment.

A significant firmware advisory or the end of vendor support for the device.

Repeated connectivity problems, unexplained blocked traffic or unauthorized configuration changes.

Changes to compliance, insurance or customer security requirements.

What should a firewall review cover?

·       Rule base: Confirm that inbound and outbound rules have a valid business purpose, correct source and destination, necessary services and an identifiable owner.

·       Unused and duplicate rules: Remove or disable obsolete entries through an approved change process. Review temporary rules and overly broad access.

·       Administrative access: Limit management access to authorized people and trusted paths. Use individual administrator accounts and MFA where supported.

·       VPN configuration: Review site-to-site and remote-access VPNs, inactive accounts, authentication methods, permitted networks and encryption settings.

·       Firmware and subscriptions: Confirm vendor support, relevant updates and the status of security-service subscriptions or certificates.

·       Logging and alerts: Check that important security events are recorded, time settings are correct, storage is adequate and alerts reach the responsible team.

·       Network segmentation: Verify that guest, user, server, management and other sensitive networks are separated according to business requirements.

·       Backups and recovery: Maintain a protected configuration backup and document how the firewall would be restored or replaced after failure.

Should every old rule be deleted?

No. Age alone does not make a rule unnecessary. A long-standing rule may support a critical application, while a recently added rule may be too broad. Each rule should be evaluated using its purpose, owner, traffic evidence, exposure and operational impact.

Changes should follow a controlled process with documentation, approval and a rollback plan. Deleting rules without understanding dependencies can interrupt business applications, phones, remote access or communication between locations.

Who should perform the review?

The reviewer should understand firewall policy, routing, VPNs, the network design and the business services being protected. They also need authorized administrative access and a clear scope.

Whenever possible, the review should include input from the business owner of each important service. An IT engineer can identify the technical effect of a rule, but the relevant department may be needed to confirm whether access is still required.

What should the final report contain?

A useful report separates urgent security concerns, recommended improvements and informational observations. Each item should explain the business impact, evidence, proposed action and any dependency or downtime risk.

The review should not automatically authorize remediation. Configuration changes, upgrades, licensing and further testing should be agreed separately so the business can approve the scope and timing.