ACSP VLANs and Link Aggregation 3 — Questions and Answers
Question 1: Which hashing algorithm component is NOT typically used by Aruba CX switches for LAG load balancing?
- VLAN ID of the frame (Correct answer)
- Source and destination MAC address
- Source and destination IP address
- Layer 4 source and destination port
Correct answer: VLAN ID of the frame
LAG load balancing hashes on MAC, IP, and L4 port fields, but VLAN ID is not a standard hashing input for load distribution.
Question 2: A network engineer configures VLAN 99 as the management VLAN on an Aruba CX switch. Which additional step is required to manage the switch via SSH over VLAN 99?
- Assign an IP address to the VLAN 99 SVI (Correct answer)
- Enable SSH on the physical port in VLAN 99
- Add VLAN 99 to the allowed list of the uplink trunk
- Configure VLAN 99 as the native VLAN on all ports
Correct answer: Assign an IP address to the VLAN 99 SVI
The switch needs an IP address configured on the VLAN 99 SVI (Switch Virtual Interface) to route management traffic.
Question 3: When using LACP in passive mode on both ends of a link, what is the result?
- The LAG will never form because neither side initiates negotiation (Correct answer)
- The LAG forms after a 30-second timeout
- One side automatically switches to active mode
- The LAG forms using static fallback
Correct answer: The LAG will never form because neither side initiates negotiation
LACP passive mode waits for the peer to initiate; if both sides are passive, neither sends PDUs and the LAG never establishes.
Question 4: On an Aruba CX switch, which VLAN configuration is required before a port can be assigned to that VLAN?
- The VLAN must be created in the global VLAN database (Correct answer)
- The VLAN must be assigned a name
- The VLAN must be added to an uplink trunk first
- The VLAN must have an SVI configured
Correct answer: The VLAN must be created in the global VLAN database
A VLAN must exist in the global VLAN database before it can be assigned to any port as an access or trunk VLAN.
Question 5: What is the purpose of the LACP 'short' timer compared to the 'long' timer?
- Short timer sends PDUs every 1 second for faster failure detection versus every 30 seconds with long timer (Correct answer)
- Short timer forms the LAG faster during initial negotiation
- Short timer reduces the number of active ports in the LAG
- Short timer is used only on access ports, long timer on trunk ports
Correct answer: Short timer sends PDUs every 1 second for faster failure detection versus every 30 seconds with long timer
The LACP short timer transmits PDUs every 1 second (timeout 3 seconds), enabling much faster link failure detection compared to the long timer's 30-second interval.
Question 6: An Aruba switch trunk port shows VLAN 50 as 'inactive'. What is the most likely cause?
- VLAN 50 has not been created on the switch (Correct answer)
- The port is in err-disabled state
- VLAN 50 is not in the allowed list of the trunk
- The SVI for VLAN 50 is shutdown
Correct answer: VLAN 50 has not been created on the switch
A VLAN appearing inactive on a trunk most commonly means the VLAN does not exist in the switch's VLAN database.
Question 7: Which Aruba CX feature allows a single physical switch to be logically divided, with each partition having its own VLAN and routing table?
- VRF (Virtual Routing and Forwarding) (Correct answer)
- VLAN pooling
- VSF (Virtual Switching Framework)
- MSTP regions
Correct answer: VRF (Virtual Routing and Forwarding)
VRF creates multiple independent routing instances on a single switch, each with its own routing and forwarding table, enabling network segmentation.
ACSP VLANs and Link Aggregation 3
Which hashing algorithm component is NOT typically used by Aruba CX switches for LAG load balancing?