Pass the HP Aruba Certified Switching Expert HPE7-A08 Questions and answers with ValidTests

Comprehensive Detailed Explanation:

When a recent configuration change causes a spike in CPU utilization that negatively impacts users, the fastest way to restore normal operation is to revert the change. This rollback immediately removes the offending configuration, potentially stabilizing the CPU and restoring service.

Rebooting the switch (Option A) is disruptive and takes more time.

Disabling debug logging (Option C) may help if debug is causing high CPU, but it doesn't undo config changes.

Pausing NAE monitoring (Option D) only suspends monitoring and doesn’t address the root cause.

Hence, reverting the recent config change is the best immediate action.

The question concerns an OSPF configuration where the interface does not come up as expected.

Common reasons for no OSPF adjacency or interface participation include:

Interfaces being passive (no adjacency formed)

Mismatched OSPF process IDs

Missing loopback interfaces (for router ID)

Layer-3 interfaces not associated with VRFs when VRFs are configured

Option D (a Layer-3 interface has not been associated with a VRF) is the root cause because in Aruba CX switches, when VRF is configured, all Layer-3 interfaces that participate in OSPF must be associated with the correct VRF instance to establish adjacency and participate correctly.

If an interface is not part of the VRF configured for OSPF, it will not appear in the OSPF interface list or form neighbors.

The issue is VMware vMotion traffic on VLAN 3903 failing, while other VLANs work normally. vMotion traffic requires support for larger frame sizes (jumbo frames) because vMotion packets are large and benefit from increased MTU to improve performance and reduce fragmentation.

Configuring jumbo frames on VLAN 3903 ensures that frames on this VLAN can use an MTU larger than the default 1500 bytes.

Configuring jumbo on the interface alone may not be sufficient if the VLAN itself is not set to support jumbo frames.

Setting MTU on VLAN or interface might not work unless jumbo frames are enabled.

The customer wants to tunnel traffic from APs through CX switches, similar to what they currently do with a gateway cluster. Aruba’s User-Based Tunneling (UBT) is designed specifically for this use case. UBT allows traffic from wireless and wired clients to be tunneled to a centralized gateway or controller for policy enforcement and traffic inspection.

IPSec and GRE are general tunneling protocols but not Aruba’s recommended solution for AP traffic.

VNBT relates to colorless ports and dynamic segmentation, not tunneling client traffic.

Thus, UBT is the correct tunneling solution for AP traffic through CX switches.

The Aruba CX switches REST API supports the JSON (JavaScript Object Notation) data format for both requests and responses. JSON is widely adopted for REST APIs due to its lightweight and readable format.

XML and YAML are not supported for REST API on CX switches.

SOAP is a different protocol not used by Aruba CX REST API.

Therefore, JSON is the correct and supported data format.

When a recent routing change causes an outage affecting all users, the recommended immediate action is to restore the last-known working configuration to quickly return the network to a stable state. This is critical to minimize downtime and impact.

Asking customers to send logs or explaining the issue takes time and delays remediation.

Collecting show tech and opening TAC cases can be done after restoring service.

Hence, the quickest way to mitigate the impact is to restore the last known good configuration.

The error message " Invalid input: interface " typically appears if the switch is managed by HPE Aruba Central, which restricts CLI interface configuration to prevent configuration drift. When managed externally, certain commands are disabled or locked.

Password recovery mode or authorization enabled would not cause this error.

Manager context is not a concept in Aruba CX CLI.

LACP (Link Aggregation Control Protocol) modes can be active or passive. When two switches are both configured in passive mode, no LACP packets are initiated, causing the link aggregation to fail or go into a block state.

Changing one side from passive to active causes that switch to initiate LACP negotiation, resolving the block state.

Changing to static mode disables LACP negotiation, which is not recommended unless both sides are static.

Changing timeout does not solve LACP block issues caused by mode mismatches.

Therefore, changing one switch’s LACP mode from passive to active is necessary to resolve the block.

If interfaces 1/1/53 and 1/1/54 connected to the primary VSX switch are disconnected and Client A experiences disruptions, configuring VSX shutdown on-split on SW-A (the primary) is necessary to prevent traffic forwarding during a split-brain scenario. This feature ensures that in case of link failure, the switch does not continue forwarding traffic independently, avoiding network loops or inconsistent states.

Configuring keepalive VLANs on downstream or upstream lags helps in monitoring but does not prevent traffic disruption.

VSX shutdown on-split must be configured on the affected primary switch to protect network integrity.

The exhibit shows a configuration for a standard Stub Area (area 1 stub). To meet the customer requirement of having only a default route, we must understand how OSPF area types filter Link State Advertisements (LSAs).

Stub Area (Current Config): Blocks Type 5 (External) LSAs. The Area Border Router (ABR) injects a Type 3 LSA default route. However, Type 3 LSAs (Inter-Area routes from other parts of the OSPF network) are still allowed in. This explains why the user still sees other OSPF routes in the table.

Totally Stubby Area (The Solution): This area type is a Cisco/Aruba enhancement to the OSPF standard. It blocks both Type 5 (External) and Type 3 (Inter-Area) LSAs. The ABR replaces all of these with a single Type 3 default route . This is the most efficient configuration for a small branch switch with limited memory and a single exit point.

AOS-CX Configuration: To convert the current " Stub " to a " Totally Stubby " area, you would add the no-summary keyword on the ABR:

Bash

router ospf 1

area 1 stub no-summary

Why other options are incorrect:

Option A and D: NSSA (Not-So-Stubby Areas) are used when you need to redistribute external routes from the branch into the rest of the OSPF network. The prompt doesn ' t mention a local external source.

Option B: This is what is currently configured and is explicitly described as not meeting the requirement.