300-415 Question 37
Select 3You are configuring a Cisco SD-WAN overlay network and need to ensure rapid failure detection and failover between transport tunnels. Bidirectional Forwarding Detection (BFD) is being implemented to monitor tunnel performance. What are the key characteristics of BFD in Cisco SD-WAN that you need to consider?
- A
BFD sessions are established automatically for all transport tunnels between SD-WAN edge devices.
- B
BFD can only monitor physical link status and cannot detect issues like high latency or packet loss.
- C
BFD operates by sending periodic hello packets to detect tunnel liveliness and performance.
- D
The default BFD hello interval and multiplier can be customized to meet specific network requirements.
- E
BFD is disabled by default for all SD-WAN tunnels and must be manually enabled.
Show answer and explanation
Correct answers: A, C, D
Explanation
BFD in Cisco SD-WAN is a key protocol for monitoring transport tunnels. It is automatically enabled and establishes sessions for all tunnels to ensure rapid failure detection and failover. BFD hello packets are sent periodically to monitor tunnel status, and its parameters (such as hello interval and multiplier) can be customized to optimize performance. This ensures that SD-WAN networks remain resilient and can respond quickly to link degradations or failures.
- A. Correct.
Correct. In Cisco SD-WAN, BFD sessions are automatically established for every transport tunnel between SD-WAN edge devices, ensuring fast detection of tunnel failures.
- B. Incorrect.
Incorrect. BFD not only monitors physical link status but also detects other issues such as high latency, packet loss, and jitter within transport tunnels.
- C. Correct.
Correct. BFD operates by sending periodic hello packets, which are used to monitor the liveliness and performance of transport tunnels.
- D. Correct.
Correct. The default BFD hello interval and multiplier can be adjusted to suit specific network performance and failover requirements.
- E. Incorrect.
Incorrect. BFD is enabled by default for all SD-WAN tunnels, ensuring immediate monitoring and failover capabilities without manual configuration.