AOS-CX VSF and VSX Flashcards

A network administrator is designing a highly available core layer using two Aruba 8325 switches. The primary requirement is to allow for live software upgrades with no downtime and to maintain independent control planes for maximum resiliency. Which Aruba AOS-CX technology should be used?

Answer: VSX (Virtual Switching Extension)

VSX is the ideal technology for this scenario. It provides high availability by allowing two switches to act as a single logical device at Layer 2, but maintain separate, independent control planes at Layer 3. This dual control plane architecture is key to performing live, non-disruptive software upgrades.

An engineer is configuring a VSF stack using Aruba 6300M switches. What is a key requirement to enable VSF split-detection?

Answer: Connecting the out-of-band management (OOBM) ports of the Conductor and Standby members, either directly or through a management network.

For VSF split-detection to function, the out-of-band management (OOBM) ports on the conductor and standby members must be connected. This connection allows the members to communicate even if the VSF links themselves are severed, preventing a split-brain scenario where both switches assume the conductor role.

In an Aruba AOS-CX VSX environment, what is the primary purpose of the keepalive connection?

Answer: To provide a heartbeat mechanism to detect a split-brain scenario when the ISL is down.

The VSX keepalive is a lightweight, out-of-band heartbeat mechanism (typically a UDP-based probe) that runs between the two VSX switches. Its sole purpose is to distinguish between a secondary switch failure and an Inter-Switch Link (ISL) failure. If the ISL goes down but the keepalive is still up, the secondary switch knows the primary is still active and will disable its own VSX LAG interfaces to prevent a network loop, thus avoiding a split-brain condition.

A company is deploying a stack of eight Aruba 6200F switches in a wiring closet to provide user access. They need a simplified management approach where all eight switches are managed as a single logical device with a unified control plane. Which technology should be implemented?

Answer: Virtual Switching Framework (VSF)

VSF is designed for stacking multiple access layer switches (like the 6200F and 6300 series) into a single logical device. This creates a shared control and management plane, simplifying configuration and monitoring. VSX is limited to two switches and is typically used in the aggregation or core layer.

Which of the following statements accurately describes a key difference between AOS-CX VSF and VSX?

Answer: VSX allows for active-active Layer 3 forwarding and gateway redundancy, while VSF operates as a single logical router.

A primary advantage of VSX is its dual control plane, which enables active-active Layer 3 forwarding using Active Gateway, providing superior redundancy and load balancing compared to VSF. In a VSF stack, the entire stack acts as a single device with one control plane and one router IP.

During a VSX split-brain event, where both the Inter-Switch Link (ISL) and the keepalive connection have failed, what is the default behavior of the secondary VSX switch?

Answer: It maintains all its links in an active state, becoming a second primary switch.

In a true split-brain scenario where both the ISL and keepalive fail, the secondary switch can no longer determine the state of the primary peer. In this situation, the secondary switch assumes the primary has failed and also becomes a primary, bringing up its interfaces to continue forwarding traffic. This can cause duplicate IP and MAC addresses on the network, but is designed to maintain connectivity for its connected devices. The keepalive mechanism is what normally prevents this by telling the secondary to shut down its VSX links if the ISL fails.