300-420 Question 223
Select 3A retail company operates a primary data center and has deployed a secondary site as a disaster recovery location. The company uses an MPLS network as its primary connectivity to branch offices and is designing backup connectivity to maintain business continuity in case of primary link failure. Which of the following design considerations are most important when implementing backup connectivity solutions?
- A
Ensure the backup link supports the same bandwidth as the primary MPLS circuit to maintain performance.
- B
Implement a different transport technology, such as broadband Internet, for the backup link to reduce the risk of a single point of failure.
- C
Use a routing protocol that can dynamically failover to the backup link when the primary MPLS circuit is unavailable.
- D
Configure the backup link to always be active to distribute traffic across both primary and backup links.
- E
Ensure the backup link uses a different physical path to prevent failure due to common outages.
Show answer and explanation
Correct answers: B, C, E
Explanation
When designing backup connectivity, it is crucial to focus on resilience and failover capabilities. Using a different transport technology (e.g., broadband Internet) and physical path reduces risks from shared points of failure. Dynamic routing protocols enable automated failover, ensuring business continuity with minimal manual intervention. While bandwidth matching and active-active configurations may have advantages, they are not primary considerations for backup connectivity in most enterprise designs.
- A. Incorrect.
While matching the bandwidth of the primary link may be desirable, it is not always cost-effective or necessary for backup connectivity. The focus should be on maintaining critical services during a failure.
- B. Correct.
Using a different transport technology, such as broadband Internet, minimizes the risk of a single point of failure by diversifying connectivity methods.
- C. Correct.
Dynamic failover using a routing protocol ensures seamless switching to the backup link when the primary link fails, maintaining service availability.
- D. Incorrect.
Configuring the backup link to always be active may not be ideal for cost or performance reasons, and it may not align with the role of a true backup link.
- E. Correct.
Using a different physical path for the backup link ensures resilience against failures caused by shared infrastructure, such as fiber cuts or equipment failures.