300-420 Question 214
Select 3A company has deployed a single-homed design for their branch office, where the branch is connected to a single ISP using a single link. The company wants to ensure that the design provides basic reliability while minimizing costs. Which of the following considerations should be factored into this single-homed design?
- A
The branch office must implement a backup Internet link to another ISP to ensure redundancy.
- B
The branch office should configure static routing or BGP depending on the ISP's requirements.
- C
The company should monitor the single link's performance to proactively identify potential issues.
- D
The design inherently provides fault tolerance and redundancy as it uses one ISP.
- E
The availability of Service Level Agreements (SLAs) with the ISP should be reviewed.
Show answer and explanation
Correct answers: B, C, E
Explanation
In a single-homed design, the branch office connects to the network using a single ISP and a single link. While this keeps costs low, it lacks redundancy and fault tolerance. To mitigate risks in this design, static routing or basic BGP configurations should be implemented based on the ISP's requirements, the link's performance should be continuously monitored, and the ISP's SLAs must be reviewed to understand their commitments to uptime and reliability. Adding a backup link or another ISP would change the design to dual-homed and is not applicable here.
- A. Incorrect.
Incorrect. A single-homed design does not include a backup link, so implementing a second link would not align with the definition of single-homed. This would instead make the design dual-homed.
- B. Correct.
Correct. Single-homed designs often rely on static routing or basic BGP peering, depending on the ISP's requirements. This ensures basic connectivity without the complexity of dynamic routing protocols.
- C. Correct.
Correct. Monitoring the performance of the single link is critical in a single-homed design, as there is no backup link available. Proactive monitoring helps identify and address issues before they impact business operations.
- D. Incorrect.
Incorrect. A single-homed design does not provide fault tolerance or redundancy, as there is only one ISP and one link. If the link fails, the branch will lose connectivity.
- E. Correct.
Correct. Reviewing the ISP's SLAs is important in a single-homed design to ensure the ISP can meet the business's reliability and uptime requirements, given the lack of redundancy.