CCDE: Cisco Certified Design Expert (Practical) — Question 234

Two routers R1 and R2 are directly connected through an Ethernet link. Both routers are running OSPF. OSPF has been registered with BFD and BFD is running in asynchronous mode with the echo function enabled. Which two actions occur that are related to the echo function? (Choose two.)

Answer options

• A. BFD echo packets are sent from forwarding engines along the Layer 2 path to perform detection
• B. BFD control packets are sent at a higher pace because the echo function is enabled
• C. BFD sessions at either end actively participate in the forwarding of echo packets
• D. BFD control packets are sent at a slower pace because the echo function is enabled
• E. Only BFD control packets are sent from forwarding engines along the Layer 2 path to perform detection

Correct answer: A, D

Explanation

The correct answers are A and D. A is correct because BFD echo packets are indeed sent to verify connectivity over the Layer 2 path. D is correct as the echo function causes BFD control packets to be sent less frequently, which is contrary to option B. Options B, C, and E are incorrect as they misrepresent how the echo function impacts BFD operations.