Some traffic management features require that you set a bandwidth limit for each network interface. For example, you must configure the Outgoing Interface Bandwidth setting to use QoS marking and prioritization.
If you set the Outgoing Interface Bandwidth to anything other than 0, the outgoing bandwidth through the interface is limited to the value you specify. If you do not change this setting from the default value of 0, the outgoing bandwidth is set to the auto-negotiated link speed for that interface.
After you set this limit, your Firebox or XTM device can complete basic prioritization tasks on network traffic to prevent problems with too much traffic on the specified interface. Also, a warning appears in
To set the bandwidth limit:
About Traffic Management and QoS
Define a Traffic Management Action in v11.8.x and Lower