300-420 Question 226
Select 3A company has deployed two redundant Layer 3 switches in their enterprise network to ensure high availability. Both switches are configured with HSRP (Hot Standby Router Protocol) to provide gateway redundancy. During a failover test, it was observed that the failover time was longer than expected, causing traffic disruption. Which of the following configurations can help minimize failover time in this scenario?
- A
Reduce the HSRP hello and hold timers.
- B
Enable HSRP preemption on the primary device.
- C
Configure a higher HSRP priority on the backup device.
- D
Enable rapid spanning tree protocol (RSTP) on the switches.
- E
Implement Bidirectional Forwarding Detection (BFD) with HSRP.
Show answer and explanation
Correct answers: A, B, E
Explanation
Reducing HSRP hello and hold timers and enabling preemption on the primary device are essential configurations to optimize HSRP failover time. Additionally, integrating BFD with HSRP can significantly enhance failure detection speed. The other options either address unrelated issues or do not directly impact HSRP failover timing.
- A. Correct.
Reducing the HSRP hello and hold timers allows the standby router to detect a failure more quickly and take over the active role, minimizing failover time.
- B. Correct.
Enabling HSRP preemption on the primary device ensures that when the primary router comes back online, it can reclaim its role as the active router, which helps maintain predictable failover behavior.
- C. Incorrect.
Configuring a higher HSRP priority on the backup device would result in the backup router becoming active by default, which does not address the issue of failover time.
- D. Incorrect.
Enabling rapid spanning tree protocol (RSTP) improves layer 2 convergence but does not directly impact HSRP failover time, which operates at layer 3.
- E. Correct.
Implementing Bidirectional Forwarding Detection (BFD) with HSRP provides a more rapid mechanism for detecting link failures, reducing failover time.