300-420 Question 86
Select 4A company is designing the Layer 2 infrastructure for their campus network. They want to ensure high availability, scalability, and fast convergence while minimizing the risk of Layer 2 loops. Which design considerations should they follow?
- A
Implement Rapid Spanning Tree Protocol (RSTP) to achieve fast convergence.
- B
Use a hierarchical design with access, distribution, and core layers.
- C
Deploy Layer 2 EtherChannel for redundancy between switches.
- D
Enable spanning-tree portfast on all trunk ports to reduce forwarding delays.
- E
Avoid VLAN spanning multiple access layer switches to limit fault domains.
Show answer and explanation
Correct answers: A, B, C, E
Explanation
To design a robust Layer 2 campus infrastructure, it's important to consider fast convergence mechanisms (like RSTP), a scalable hierarchical topology, redundancy through technologies like EtherChannel, and fault domain isolation by limiting VLAN spans. These design principles ensure the network is highly available, scalable, and protected against risks such as Layer 2 loops.
- A. Correct.
Implementing Rapid Spanning Tree Protocol (RSTP) ensures fast convergence in the Layer 2 topology, which is essential for high availability.
- B. Correct.
A hierarchical design with access, distribution, and core layers provides scalability and simplifies network management.
- C. Correct.
Layer 2 EtherChannel provides redundancy and increases bandwidth between switches, reducing the risk of single points of failure.
- D. Incorrect.
Enabling spanning-tree portfast on all trunk ports is not recommended, as it can cause loops if applied incorrectly. Portfast should only be enabled on edge ports connected to end devices.
- E. Correct.
Limiting VLANs to a single access layer switch helps to minimize the impact of Layer 2 faults, improving network stability and scalability.