Free Practice Questions for HP HPE7-A07 Exam

Comprehensive and Detailed Explanation (Verified Extract from HPE Aruba Networking Switching Documentation)

VOQ (Virtual Output Queuing) is a hardware-based queuing mechanism used in the ArubaOS-CX architecture to prevent head-of-line blocking and minimize packet drops in high-throughput environments.

How VOQ Works:

Each ingress port maintains a separate queue for every egress port in the system.

When a packet arrives, it is placed in the ingress buffer corresponding to its destination egress port.

This structure ensures that traffic destined for one congested egress port does not block packets heading to other ports.

This architecture is critical in high-speed modular switches and aggregation cores (such as the Aruba 8400 and 10000 Series), allowing the fabric interconnect to forward traffic efficiently without dropping packets due to port congestion.

ArubaOS-CX Technical Extract:

“Virtual Output Queuing (VOQ) provides per-egress-port queuing at ingress buffers, preventing head-of-line blocking and ensuring high throughput across the switch fabric. Each ingress queue corresponds to a specific egress port, allowing packets to be transmitted as soon as the egress port becomes available.”

Option Analysis:

A. Incorrect – Refers to priority marking (QoS), not VOQ operation.

B. Correct – VOQ provides ingress buffers with queues for each egress port, reducing dropped packets and head-of-line blocking.

C. Incorrect – VOQ is not related to LACP or VSX link aggregation.

D. Incorrect – VOQ does not dynamically allocate egress buffer space; it segregates ingress queues per egress destination.

Final Verified Answer: B

Reference Sources (HPE Aruba Official Materials):

Aruba AOS-CX Technical Architecture Overview – Virtual Output Queuing (VOQ)

Aruba 8400/10000 Series Switches Hardware and Performance Guide

Aruba Certified Switching Expert (ACSE) Study Guide – Switch Fabric and Queuing Mechanisms

In OSPF, when a router learns about an external network through both E1 and E2 advertisements, and if both have the same path cost, the router will prefer the E1 path. This is because E1 routes consider both the external cost to reach the external network and the internal cost to reach the ASBR, providing a more comprehensive metric. E2 routes only consider the external cost and ignore the internal cost to the ASBR, which could potentially lead to suboptimal routing. Therefore, the router will choose the E1 path due to its more accurate representation of the total path cost.