300-420 Question 89
Select 3You are designing a large Layer 2 network for a campus environment with hundreds of switches. The design must ensure STP (Spanning Tree Protocol) scalability while minimizing convergence time and ensuring efficient management. Which of the following design considerations would best address these requirements?
- A
Use Rapid PVST+ instead of traditional IEEE 802.1D STP.
- B
Design the network with a flat Layer 2 topology to simplify STP.
- C
Enable BPDU Guard on all edge ports connected to end devices.
- D
Implement Multiple Spanning Tree Protocol (MSTP) to group VLANs into instances.
- E
Increase the STP timer values to reduce the frequency of recalculations.
Show answer and explanation
Correct answers: A, C, D
Explanation
For a scalable STP design, it is essential to use advanced protocols like Rapid PVST+ for faster convergence, enable features like BPDU Guard to prevent topology issues, and consider MSTP to reduce the complexity of managing multiple VLANs in large environments. Avoiding flat Layer 2 topologies and tuning STP timers inappropriately ensures the network remains efficient and resilient.
- A. Correct.
Using Rapid PVST+ enhances STP scalability by reducing convergence time through faster transitions and improved performance compared to 802.1D STP.
- B. Incorrect.
A flat Layer 2 topology increases the size of the STP domain, which can lead to scalability challenges and longer convergence times.
- C. Correct.
Enabling BPDU Guard on edge ports prevents accidental loops caused by misconfigurations or unauthorized devices, contributing to a more stable and scalable STP environment.
- D. Correct.
MSTP groups VLANs into fewer spanning tree instances, which reduces the number of STP calculations, improving scalability and efficiency.
- E. Incorrect.
Increasing STP timer values slows down the protocol's response to topology changes, which negatively impacts convergence time and is not recommended for scalability.