300-420 Question 209
Select 3An organization is designing a highly available WAN architecture for its hybrid environment, which includes on-premises data centers and applications hosted in a public cloud. The organization wants to ensure minimal downtime and uninterrupted connectivity between its on-premises network, cloud applications, and branch offices. Which of the following design considerations would best achieve high availability in this scenario?
- A
Implement dual MPLS circuits with diverse ISPs for the on-premises data center.
- B
Use a single SD-WAN controller to manage all branch connectivity.
- C
Enable dynamic routing protocols such as BGP or OSPF for automated failover.
- D
Deploy redundant VPN tunnels between the on-premises site and the cloud provider.
- E
Configure a single link from each branch office to the on-premises network for simplicity.
Show answer and explanation
Correct answers: A, C, D
Explanation
High availability for enterprise WAN in hybrid environments requires redundancy at multiple levels, including physical links, routing protocols, and connectivity to the cloud. Dual MPLS circuits with diverse ISPs eliminate reliance on a single provider, while dynamic routing protocols ensure automated failover. Redundant VPN tunnels to the cloud provider maintain connectivity to critical cloud services. These considerations collectively address the need for minimal downtime and uninterrupted connectivity in a hybrid network design.
- A. Correct.
Implementing dual MPLS circuits with diverse ISPs provides redundancy and ensures that the on-premises data center remains connected in case of a failure of one circuit or ISP.
- B. Incorrect.
Using a single SD-WAN controller without redundancy creates a single point of failure, which contradicts the goal of high availability.
- C. Correct.
Dynamic routing protocols like BGP or OSPF facilitate automated failover, ensuring traffic is rerouted immediately in case of any connectivity issues.
- D. Correct.
Redundant VPN tunnels between the on-premises site and the cloud provider allow for failover, ensuring uninterrupted connectivity to cloud-hosted applications.
- E. Incorrect.
A single link from each branch office to the on-premises network creates a single point of failure, which does not align with high availability design principles.