How do firewalls aid in protecting mission-critical systems?

Firewalls play a crucial role in protecting mission-critical systems by monitoring and controlling network traffic according to predefined security rules. This proactive approach enables organizations to filter out unauthorized access attempts while allowing legitimate traffic to pass through.

By establishing rules that specify what types of traffic are acceptable and what should be blocked, firewalls create a protective barrier around sensitive systems. This is particularly important for mission-critical systems, which often contain sensitive data or are involved in essential operations where downtime or data breaches can result in significant consequences.

In contrast to the other options, firewalls do not disable all inbound network traffic, as that would prevent legitimate users from accessing necessary resources. Firewalls cannot completely remove all vulnerabilities from a system since new threats may emerge or existing ones may not have been identified. Additionally, while some firewalls may include features for backup, their primary purpose is not to facilitate automatic data backups, but rather to enforce security protocols for incoming and outgoing network traffic.