Configure and Verify Differentiated Services Code Points DSCP and 802.1p (CoS) POWERSWITCH-CAMPUS-DEPLOY Practice Questions (Page 3)

Questions 11–15

1. 11foundation · easy

   In an 802.1Q tagged Ethernet frame, which bits are used for 802.1p priority?

   • AThe 12-bit VLAN ID field
   • BThe 2-bit Canonical Format Indicator (CFI)
   • CThe 3-bit Priority Code Point (PCP) field
   • DThe 1-bit Drop Eligible Indicator (DEI)
   Reveal Solution Discussion Select an answer first
2. 12foundation · easy

   How does a switch typically map DSCP values to 802.1p priority classes?

   • ABy using the DSCP value directly as the 802.1p priority
   • BBy using a configurable mapping table that assigns each DSCP value to a specific 802.1p priority
   • CBy using the IP precedence bits to derive the 802.1p priority
   • DBy using the DSCP value modulo 8 to compute the priority
   Reveal Solution Discussion Select an answer first
4. 13foundation · easy

   What is the purpose of 802.1p priority tagging in an Ethernet frame?

   • ATo indicate the frame's VLAN ID
   • BTo provide a Layer 2 QoS marking that switches can use to prioritize frames
   • CTo encrypt the frame payload for secure transmission
   • DTo identify the source MAC address of the frame
   Reveal Solution Discussion Select an answer first
5. 14application · medium

   A network engineer is configuring QoS on a Dell PowerSwitch. The switch receives traffic marked with DSCP AF32 (28) and needs to map it to the appropriate 802.1p priority. According to the standard DSCP-to-802.1p mapping, which priority should AF32 map to?

   • A5
   • B4
   • C3
   • D2
   Reveal Solution Discussion Select an answer first
6. 15expert · hard

   A Dell PowerSwitch port connects to a Cisco IP phone. The phone marks voice traffic with DSCP EF (46) and 802.1p priority 5. The port is currently configured to trust 802.1p. The network team notices that voice traffic is being queued at a lower priority than expected. They suspect the DSCP marking is being ignored. What is the most likely cause and the correct fix?

   • AThe port trusts 802.1p, so the DSCP EF marking is ignored. Change the port to trust DSCP.
   • BThe 802.1p priority 5 is not mapped to the correct queue. Reconfigure the queue mapping.
   • CThe phone is not sending DSCP EF. Verify the phone's configuration.
   • DThe switch is re-marking DSCP EF to a lower value. Check the DSCP override configuration.
   Reveal Solution Discussion Select an answer first