300-420 Question 135
Select 2An enterprise is designing an optimal topology for their campus network to ensure scalability, redundancy, and high availability. The design includes a three-tier architecture with core, distribution, and access layers. Which of the following design considerations align with building an optimal topology for this scenario?
- A
Use a full mesh topology between the access layer and the distribution layer for maximum redundancy.
- B
Design the core layer to provide high-speed forwarding and avoid direct connections to endpoints.
- C
Implement equal-cost multipath (ECMP) routing in the core layer to improve load balancing.
- D
Place Layer 2 VLANs spanning across the entire campus to simplify management.
- E
Ensure the access layer connects directly to the core layer to reduce complexity.
Show answer and explanation
Correct answers: B, C
Explanation
An optimal campus network topology leverages a three-tier architecture with well-defined roles for each layer. The core layer should focus on high-speed forwarding without directly connecting endpoints, while ECMP ensures efficient load balancing. Avoiding unnecessary complexity, such as spanning Layer 2 VLANs across the campus or using full mesh designs, ensures scalability and high availability.
- A. Incorrect.
Using a full mesh topology between the access and distribution layers is not optimal because it adds unnecessary complexity and cost without significant benefit. A partial or structured redundancy design is more appropriate.
- B. Correct.
The core layer should focus on high-speed forwarding and should not connect directly to endpoints to avoid overloading the core and to maintain scalability.
- C. Correct.
ECMP routing in the core layer is a best practice for load balancing and ensuring optimal utilization of network paths in a scalable topology.
- D. Incorrect.
Spanning VLANs across the entire campus network is not recommended as it introduces risks such as large broadcast domains and difficulties in fault isolation.
- E. Incorrect.
Connecting the access layer directly to the core layer bypasses the distribution layer, which violates the principles of the three-tier architecture and reduces scalability.