ACSP VLANs and Link Aggregation 5 — Questions and Answers
Question 1: A network administrator configures VLAN translation on an Aruba CX switch. What does this feature accomplish?
- It maps an incoming VLAN tag to a different VLAN ID as traffic enters the switch (Correct answer)
- It converts 802.1Q tagged frames to 802.1ad (QinQ) frames
- It removes VLAN tags from all frames on a port
- It duplicates frames across multiple VLANs simultaneously
Correct answer: It maps an incoming VLAN tag to a different VLAN ID as traffic enters the switch
VLAN translation (also called VLAN mapping) rewrites the VLAN ID of incoming frames, enabling connectivity between networks using different VLAN numbering schemes.
Question 2: What happens to a LAG member port on Aruba CX when its physical link goes down while LACP is active?
- The port is automatically removed from the LAG and traffic redistributes across remaining members (Correct answer)
- The LAG is torn down and must be manually re-established
- LACP switches the port to passive mode until the link recovers
- Traffic continues to hash to the failed port until timers expire
Correct answer: The port is automatically removed from the LAG and traffic redistributes across remaining members
When a LAG member's physical link fails, LACP detects the failure and removes the port from the bundle, redistributing load to the remaining active members.
Question 3: Which VLAN range is reserved for internal use and cannot be assigned to user ports on Aruba CX switches?
- 4094 and above (implementation-specific reserved range) (Correct answer)
- 1-100
- 1000-1999
- 2000-2999
Correct answer: 4094 and above (implementation-specific reserved range)
Aruba CX reserves certain VLAN IDs at the upper end of the range (near 4094) for internal switch operations, and these cannot be assigned to user-facing ports.
Question 4: An Aruba CX switch is configured with QinQ (802.1ad). What is the outer tag called in a double-tagged frame?
- S-Tag (Service Tag) (Correct answer)
- C-Tag (Customer Tag)
- P-Tag (Provider Tag)
- B-Tag (Backbone Tag)
Correct answer: S-Tag (Service Tag)
In 802.1ad QinQ, the outer tag is the S-Tag (Service Tag) added by the service provider, while the inner tag is the C-Tag (Customer Tag) from the customer's network.
Question 5: When configuring LACP system priority on an Aruba CX switch, which value results in the switch having higher authority in LAG negotiations?
- Lower system priority value (Correct answer)
- Higher system priority value
- System priority of 32768 always wins
- System priority is irrelevant when ports have equal priority
Correct answer: Lower system priority value
A lower LACP system priority value gives the switch higher authority to determine which ports are active when there are more ports than the LAG maximum allows.
Question 6: An administrator needs to verify that VLAN 100 exists and is active on an Aruba CX switch. Which command provides this information?
- show vlan 100 (Correct answer)
- show interface vlan 100
- show vlan summary
- show running-config vlan 100
Correct answer: show vlan 100
'show vlan 100' displays the status, name, and port membership of VLAN 100, confirming whether it exists and is active.
Question 7: What is the primary advantage of using LACP over a static LAG on an Aruba CX switch?
- LACP automatically detects and responds to link failures and misconfigurations without manual intervention (Correct answer)
- LACP provides higher bandwidth than static LAG
- LACP supports more member ports than static LAG
- LACP reduces CPU overhead compared to static LAG
Correct answer: LACP automatically detects and responds to link failures and misconfigurations without manual intervention
LACP continuously exchanges PDUs to detect link failures, miscabling, and configuration mismatches, providing automatic recovery that static LAG cannot offer.
ACSP VLANs and Link Aggregation 5
A network administrator configures VLAN translation on an Aruba CX switch.
What does this feature accomplish?