Classifier-based QoS restrictions

The following restrictions apply to QoS policies configured with the classifier-based model:

A classifier-based QoS policy cannot be applied on a port or VLAN interface on which a classifier-based QoS policy is already configured. It is possible to apply a classifier-based policy of a different type, such as port mirroring.
A QoS policy that uses the rate-limit command is not supported on a port interface on which ICMP rate limiting has already been globally configured. To apply the QoS policy, you must first disable the ICMP rate limiting configuration. See the ArubaOS-Switch Multicast and Routing Guide for your switch.In cases where an ICMP rate limiting configuration is to be maintained, configure a QoS policy by adding the necessary match statements for the ICMP traffic in a class configuration, then configure a rate-limit action for the class in the policy configuration.
In a QoS policy that uses the class action rate-limit command, the rate limit is calculated on a per-module or per port-bank basis. If trunked ports or VLANs with a configured rate limit span multiple modules or port-banks, the configured rate limit is not guaranteed.
In a QoS policy that uses the class action dscp command, the DSCP value entered must be already configured with an 802.1p priority in the DSCP Policy table.