HP Aruba Certified Professional - Campus Access HPE7-A06 Question # 6 Topic 1 Discussion

The requirement is to prevent loops on Edge-1 switch ports connected to third-party CCTV switches that donotsupport STP. The solution must also include an automatic recovery feature if a port gets disabled.

Loop Prevention without STP:When connecting to non-STP devices, standard STP loop prevention (like BPDU Guard) might not work if the connected device doesn't send BPDUs. AOS-CX offers a feature called loop-protect which sends probes to detect loops in non-STP environments.

Automatic Recovery:Features that disable ports (like BPDU Guard or Loop Protect) often have a timeout or auto-recovery option (port-disable-timer for Loop Protect) allowing the port to automatically re-enable after a configured period.

Analysis of Options:

A: LACP fallback applies to LAGs, not general loop prevention.

B: TCN-guard is an STP feature, irrelevant here.

C: Suggests spanning-tree with bpdu-guard timeout. BPDU Guard detects loops by listening for BPDUs, which these CCTV switches don't send. However, the timeout featuredoesprovide the required automatic recovery mechanism if the portweredisabled by BPDU Guard.

D: UDLD detects unidirectional links, not typically bridging loops caused by topology.

Re-evaluation:The ideal AOS-CX feature is loop-protect with port-disable-timer. Since this isn't explicitly an option, we must evaluate the given choices. Option C is theonlyone that mentions a mechanism (bpdu-guard timeout) providing automatic recovery from a disabled state. While BPDU Guard isn't the right detection mechanism here, it's the closest fit regarding the auto-recoveryrequirement. It's possible the question implicitly assumes some stray BPDUs might trigger it or that it's the intended "best fit" answer despite the detection mechanism mismatch.

Conclusion:Given the options, Option C is the most plausible because it includes the timeout feature associated with bpdu-guard, fulfilling the automatic recovery requirement, even though BPDU guard itself is not the ideal detection method for loops involving non-STP devices.