300-420 Question 211
Select 3Your organization has a hybrid WAN deployment that connects on-premises data centers to multiple SaaS applications hosted in the cloud. The WAN design must ensure high availability by providing redundancy for critical traffic flows while optimizing performance. Which of the following design considerations should you implement to achieve this goal?
- A
Employ dual WAN edge routers with diverse ISPs for connectivity to the cloud.
- B
Implement path monitoring and automatic failover using technologies like IP SLA or Bidirectional Forwarding Detection (BFD).
- C
Use a single high-bandwidth MPLS circuit to carry all traffic between on-premises and cloud environments.
- D
Leverage SD-WAN to dynamically route traffic based on application performance requirements.
- E
Configure static routing to ensure consistent traffic flow and avoid routing protocol complexity.
Show answer and explanation
Correct answers: A, B, D
Explanation
High availability for enterprise WAN, especially in hybrid and cloud-connected environments, requires redundancy at multiple levels (e.g., physical, ISP diversity), rapid failure detection and recovery, and dynamic routing capabilities. A combination of dual WAN edge routers, path monitoring with failover technologies, and SD-WAN ensures resiliency, performance optimization, and seamless recovery from failures. Static routing and reliance on a single MPLS circuit fail to provide the necessary redundancy and adaptability, making them unsuitable for this scenario.
- A. Correct.
Correct: Dual WAN edge routers with diverse ISPs ensure redundancy at the physical and service provider level, minimizing the risk of single points of failure.
- B. Correct.
Correct: Path monitoring and automatic failover mechanisms such as IP SLA or BFD are critical for detecting and quickly reacting to link or path failures, ensuring high availability.
- C. Incorrect.
Incorrect: Relying on a single MPLS circuit introduces a single point of failure and does not meet the high availability requirement for a hybrid WAN design.
- D. Correct.
Correct: SD-WAN provides intelligent routing based on real-time application performance, enabling both redundancy and performance optimization in hybrid WAN environments.
- E. Incorrect.
Incorrect: Static routing lacks flexibility and does not support dynamic response to failures or performance degradation, making it unsuitable for high availability in enterprise WANs.