300-415 Question 147
Select 3A company has deployed Cisco SD-WAN with multiple branch sites. The IT team wants to configure VRRP to ensure high availability for the local gateway routers at a branch site. The team has configured two SD-WAN Edge routers as VRRP peers. After testing, they notice that traffic is not failing over to the standby router during a planned primary router shutdown. Which of the following steps should the team take to ensure proper VRRP failover functionality?
- A
Ensure that the VRRP priority value is higher on the primary router.
- B
Verify that the VRRP virtual IP address is reachable from the LAN devices.
- C
Configure OMP to advertise the VRRP virtual IP address across the SD-WAN fabric.
- D
Check the hello and hold timers configured for VRRP to ensure proper failover timing.
- E
Enable preemption on the VRRP primary router.
Show answer and explanation
Correct answers: A, B, D
Explanation
VRRP is a redundancy protocol used for high availability at the gateway level. To ensure proper failover, the primary router must have a higher priority than the standby router, the virtual IP must be reachable by LAN devices, and the hello/hold timers must be configured correctly to avoid delays in failover. While preemption is optional and OMP does not impact VRRP, these core configurations are essential for proper VRRP functionality in an SD-WAN environment.
- A. Correct.
A higher VRRP priority value ensures the router is elected as the primary router. Without this, failover behavior may not work as expected.
- B. Correct.
The VRRP virtual IP address must be reachable by LAN devices to ensure proper gateway redundancy. If not reachable, failover will not occur as expected.
- C. Incorrect.
OMP does not advertise VRRP virtual IP addresses across the SD-WAN fabric; VRRP is a local gateway protocol and does not depend on OMP for failover.
- D. Correct.
Proper hello and hold timer configuration is critical for ensuring that failover occurs within the desired time frame. Improper timer settings can delay or prevent failover.
- E. Incorrect.
Preemption is not required for basic VRRP failover functionality. It only ensures that the primary router reclaims its role when it comes back online.