Cisco APIC Layer 3 Networking Configuration Guide, Release 6.2(x)

L3Out QoS

Updated: April 17, 2026

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Describes how contracts and custom QoS policies classify Layer 3 Out traffic into QoS queues according to ingress DSCP or CoS values.

L3Out QoS is a traffic-management capability that

applies contracts at the external EPG level,
applies custom QoS policies directly to L3Out interfaces, and
classifies ingress traffic into QoS queues according to DSCP or CoS values.

L3Out QoS configuration

Beginning with Cisco APIC release 4.0(1), you can configure L3Out QoS directly on L3Out interfaces. The ingress DSCP or CoS value classifies packets and enables custom QoS policies to map traffic to Cisco ACI QoS queues.

A custom QoS policy maps DSCP or CoS values to a user queue and to a new DSCP or CoS marking value. If a value has no mapping, the QoS priority setting on the ingress L3Out interface selects the user queue, if that setting is configured.

Tip

For Cisco APIC release 4.0(1) or later, apply custom QoS policies directly to L3Out interfaces.

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