Question 50
A multi-area OSPF service-provider network carries hundreds of branch subnets. Observed: SPF CPU spikes following frequent flaps in a low-value access segment. After the correction, which result would most convincingly show that this fault is resolved?
Explanation
Correct Answer
After repair the flapping link and tune supported convergence controls without masking real failures, inspect whether sPF event frequency falls and legitimate topology changes still converge. This closes the loop between the reported observation (SPF CPU spikes following frequent flaps in a low-value access segment) and the underlying issue (Unstable access LSAs cause repeated area-wide SPF recalculation).
Incorrect Answers
It confirms an unrelated service correction: Redistribution tags and loop-prevention controls were omitted. The present case reports SPF CPU spikes following frequent flaps in a low-value access segment. Its completion test is SPF event frequency falls and legitimate topology changes still converge.
This result is useful in another case with evidence Two nodes advertise the same router ID and neighbor behavior becomes unstable. It does not test recovery from spf cpu spikes following frequent flaps in a low-value access segment. Check instead whether sPF event frequency falls and legitimate topology changes still converge.
That observation would verify a separate fault involving the totally stubby default-route and interarea advertisement policy is not consistently applied. Its symptom is Branch routers still receive numerous interarea type-3 advertisements after migration. For this case the actual issue is unstable access lsas cause repeated area-wide spf recalculation, and the relevant success signal is SPF event frequency falls and legitimate topology changes still converge.