Which of the following is a best practice for configuring firewall policies?

Setting the least privileged access necessary is a fundamental principle of network security known as the principle of least privilege. This practice involves granting users and systems only the access they need to perform their tasks, and nothing more. By implementing this approach in firewall policies, you effectively minimize the potential attack surface.

When you configure firewall policies to allow only the necessary traffic, you reduce the risk of unauthorized access and potential exploits. This is particularly important because it helps in ensuring that any vulnerabilities in the network or application are not easily exploitable through excessive permissions. Firewalls configured with the least privilege in mind serve as a crucial layer of defense against both internal and external threats.

This practice is proactive in maintaining a secure posture and aligns closely with overall security best practices, including regular reviews and adjustments based on changing organizational needs or emerging threats. It contrasts sharply with less secure options such as allowing all traffic and restricting later, which can lead to unmonitored vulnerabilities, or using a single policy for all traffic, which fails to consider the varied requirements of different applications and services.