300-415 Question 146
Select 2In a Cisco SD-WAN deployment, a customer is using VRRP to provide gateway redundancy for branch offices. However, they notice that when the primary device in the VRRP group fails, there is a delay before traffic begins to flow through the secondary device. Which of the following actions can reduce the failover time in this scenario?
- A
Reduce the VRRP advertisement interval on all devices in the group
- B
Enable preemption on the secondary device
- C
Increase the VRRP priority value of the secondary device
- D
Configure Bidirectional Forwarding Detection (BFD) for VRRP
- E
Disable preemption on the primary device
Show answer and explanation
Correct answers: A, D
Explanation
In VRRP, failover time is primarily influenced by the advertisement interval and the failure detection mechanism. Reducing the advertisement interval ensures faster detection of the active router's unavailability. Additionally, integrating BFD with VRRP provides sub-second failure detection, which further minimizes downtime and improves failover performance. These two actions directly address the issue of delayed failover in the described scenario.
- A. Correct.
Reducing the VRRP advertisement interval decreases the time it takes to detect a failure, thus speeding up failover. This is a valid action to reduce failover time.
- B. Incorrect.
Enabling preemption on the secondary device does not directly reduce failover time. Preemption allows a device with a higher priority to take over the active role but does not affect the detection or transition speed.
- C. Incorrect.
Increasing the VRRP priority value of the secondary device does not reduce failover time. It only influences which device becomes the active gateway during normal operation.
- D. Correct.
Configuring BFD for VRRP can significantly reduce failover time by enabling faster failure detection. This is a valid action to address the issue.
- E. Incorrect.
Disabling preemption on the primary device is unrelated to failover time and is not relevant to solving the described problem.