ACSP Quality of Service (QoS) 3

Question 1

On an Aruba AOS-CX switch, which QoS profile type defines the mapping between DSCP values and local priority queues?

Accepted Answer

DSCP map

Answer

A DSCP map (configured with 'qos dscp-map') defines how incoming DSCP values are translated to local queue priorities on the switch.

Question 2

Which feature allows an Aruba switch to automatically configure QoS for Cisco IP phones detected via CDP/LLDP on an access port?

Accepted Answer

Auto QoS

Answer

Auto QoS detects IP phones via CDP or LLDP and automatically applies appropriate trust settings and queue configurations for voice traffic.

Question 3

What happens to packets that exceed the configured police rate when the action is set to 'drop' on an Aruba switch?

Accepted Answer

Packets are discarded immediately

Answer

With a police action of 'drop', packets exceeding the committed rate are immediately discarded rather than buffered or remarked.

Question 4

In AOS-CX QoS, what does the 'strict' scheduling mode mean when applied to a queue?

Accepted Answer

The queue is always serviced before lower-priority queues, regardless of their content

Answer

Strict priority scheduling always services the strict queue before moving to lower-priority queues, which can starve lower queues if the strict queue is always busy.

Question 5

Which Layer 2 field is used to carry QoS markings in 802.1Q-tagged Ethernet frames on Aruba switch trunk ports?

Accepted Answer

802.1p Priority Code Point (PCP)

Answer

The 802.1p PCP field (3 bits within the 802.1Q tag) carries Class of Service (CoS) values 0–7 for Layer 2 QoS on trunk links.

(ACSP) Aruba Certified Switching Professional Practice Test

(ACSP) Aruba Certified Switching Professional Practice Test

ACSP Quality of Service (QoS) 3