A school district wants faster failure detection on Metro Ethernet links between OSPF routers. How should they compare sub-second OSPF hellos with BFD?
Select an answer to reveal the explanation.
Short Explanation
Fast hellos are like checking your mailbox every half-second—OSPF itself does all the knocking. BFD is a dedicated doorbell that can wake OSPF without flooding the protocol with tiny hellos. Same goal, less OSPF busywork with BFD.
Full Explanation
Aggressive OSPF Hello/Dead timers can shorten detection but increase protocol control-plane load and remain OSPF-specific. BFD offers a separate, lightweight failure-detection service that OSPF (and other clients) can register with, often preferred for sub-second detection on Metro links. Claiming hellos always beat BFD or that BFD cannot be fast misstates the trade-off. Choose BFD when you want independent, efficient detection feeding OSPF.