In ArubaOS-CX, a Quality of Service (QoS) policy is built using class maps and policy maps. A class map is used to classify traffic based on specific criteria. The command class-map match dscp creates a class map (or enters its configuration context) and defines the matching criterion as the Differentiated Services Code Point (DSCP) value in the IP header. This command effectively "assigns" traffic with a specific DSCP value to the defined traffic class for further policy actions like queuing or remarking.

A. qos dscp 46

This is not a valid ArubaOS-CX command for defining a traffic class or assigning a DSCP value within a QoS policy structure.

B. set traffic-class dscp 46

The set command is used within a policy map to apply an action (like remarking), not to define a class. The syntax is also incorrect.

D. ip qos dscp 46

This command syntax is not used in ArubaOS-CX for configuring modular QoS policies. It does not align with the class-map/policy-map framework.

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1. ArubaOS-CX 10.12 Quality of Service Guide

Page 21

"Configuring a class map". The guide details the process of creating a class map and using match criteria. It shows the command match dscp is used within the class-map context to classify traffic based on its DSCP value. This directly supports the structure and keywords presented in option C.

2. ArubaOS-CX 10.12 Quality of Service Guide

Page 27

"Configuring a policy map". This section shows that actions

such as setting a new DSCP value

are performed using the set dscp command within a policy map

not a class map. This confirms that options B and D

which imply setting or assigning values outside the correct context

are incorrect.