Question

Which two types of spanning tree protocols can cause suboptimal traffic flows because they assume only one spanning-tree instance for the entire bridged network? (Choose two)

a) Rapid Spanning Tree Protocol (RSTP)
b) Multiple Spanning Tree Protocol (MSTP)
c) Per-VLAN Spanning Tree (PVST)
d) Spanning Tree Protocol (STP)

Answer 1

Rapid Spanning Tree Protocol (RSTP) and Per-VLAN Spanning Tree (PVST) can cause suboptimal traffic flows.

Step-by-step explanation:

The two types of spanning tree protocols that can cause suboptimal traffic flows because they assume only one spanning-tree instance for the entire bridged network are:

• Rapid Spanning Tree Protocol (RSTP)
• Per-VLAN Spanning Tree (PVST)

RSTP is an improvement over the original Spanning Tree Protocol (STP) and aims to provide faster convergence. However, it can lead to suboptimal traffic flows as it assumes only one spanning-tree instance for the entire network. PVST is a Cisco proprietary protocol that allows for a separate spanning-tree instance for each VLAN, which can also result in suboptimal traffic flows.