A managed firewall is a firewall service operated by a third-party provider that handles monitoring, rule administration, tuning, and often updates on behalf of the customer. The customer may own the device or subscribe to a hosted service, but the day-to-day work is outsourced to specialists.
This model matters because firewall security depends on continuous maintenance, not just initial installation. Attackers often exploit stale rules, accidental exceptions, or policy drift that leaves ports and services exposed. A managed firewall can help by reviewing logs, blocking suspicious traffic, applying changes quickly, and keeping configurations aligned with business policy. The tradeoff is trust: the organization must rely on the provider’s process, visibility, and change control. In practice, managed firewalls are used both as a defense against noisy scanning and intrusion attempts, and as an operational safeguard for teams that need consistent administration across many sites or mixed firewall products.