The FortiGate firewall implementation must manage excess bandwidth to limit the effects of packet flooding types of denial-of-service (DoS) attacks.

A firewall experiencing a DoS attack will not be able to handle production traffic load. The high utilization and CPU caused by a DoS attack will also have an effect on control keep-alives and timers used for neighbor peering resulting in route flapping and will eventually black hole production traffic. The device must be configured to contain and limit a DoS attack's effect on the device's resource utilization. The use of redundant components and load balancing are examples of mitigating "flood-type" DoS attacks through increased capacity.