300-420 Question 81
Single answerA network engineer is designing an enterprise network with high availability and fast convergence requirements. They have decided to implement Bidirectional Forwarding Detection (BFD) for rapid failure detection. Which of the following statements about BFD configuration and behavior is correct?
- A
BFD operates at Layer 3 and is independent of the routing protocol in use.
- B
BFD requires neighbor devices to have identical timers to establish a session.
- C
BFD can only be used with OSPF and EIGRP routing protocols.
- D
BFD uses control packets to detect failures and requires minimal processing overhead.
Show answer and explanation
Correct answer: D
Explanation
BFD is a high-performance failure detection mechanism that reduces convergence time by quickly identifying link or path failures. It uses control packets to detect issues and operates efficiently with minimal resource consumption. While BFD needs to be integrated with routing protocols for failure detection, it is not restricted to specific protocols and does not require identical timers between neighbors.
- A. Incorrect.
Incorrect. While BFD operates alongside Layer 3 routing protocols, it is not entirely independent. BFD must be integrated with the routing protocol to detect failures and trigger convergence.
- B. Incorrect.
Incorrect. BFD does not require identical timers between neighbors. However, the timers must be negotiated during the session establishment phase to ensure compatibility.
- C. Incorrect.
Incorrect. BFD is a versatile protocol and can be used with multiple protocols like OSPF, EIGRP, BGP, and IS-IS. It is not limited to only OSPF and EIGRP.
- D. Correct.
Correct. BFD uses lightweight control packets and is specifically designed for rapid failure detection with minimal processing and bandwidth overhead.