200-301 Question 48
Single answerYou are designing a network for a medium-sized company. The company requires a three-tier architecture to ensure scalability, modularity, and fault isolation. Which of the following correctly represents the roles of the tiers in a three-tier architecture?
- A
Core layer provides high-speed interconnection between distribution layers; Distribution layer manages policy-based connectivity; Access layer connects end devices.
- B
Distribution layer provides high-speed backbone connectivity; Core layer implements policy decisions; Access layer connects end devices.
- C
Access layer provides high-speed backbone connectivity; Distribution layer manages fault isolation; Core layer connects end devices.
- D
Core layer connects end devices; Access layer provides policy enforcement; Distribution layer provides high-speed interconnection between layers.
Show answer and explanation
Correct answer: A
Explanation
The three-tier architecture consists of the core layer, distribution layer, and access layer. The core layer is responsible for high-speed interconnectivity and acts as the backbone of the network. The distribution layer enforces policies, manages routing, and provides fault isolation between access layers. The access layer connects end devices to the network, such as user PCs, printers, and other devices.
- A. Correct.
Correct. The core layer provides fast and efficient interconnection between distribution layers, the distribution layer is responsible for policy-based connectivity (such as routing and filtering), and the access layer is where end devices like PCs and printers connect.
- B. Incorrect.
Incorrect. The core layer does not implement policy decisions, and the distribution layer does not provide backbone connectivity. These roles are reversed.
- C. Incorrect.
Incorrect. The access layer does not provide backbone connectivity, and the core layer does not connect end devices. This misrepresents the roles of each tier.
- D. Incorrect.
Incorrect. The core layer does not connect end devices, and the access layer does not enforce policies. These functions are misattributed to the wrong tiers.