Cisco Certified Network Professional Practice Test 2025 – Your All-in-One Guide to Exam Success!

The significance of the correct choice lies in the nature of Rapid Per-VLAN Spanning Tree Plus (RPVST+), which is an enhancement of the Spanning Tree Protocol (STP) designed to improve network convergence times while still operating per-VLAN.

Each VLAN in an RPVST+ setup indeed has its own independent Spanning Tree instance. While this allows for optimal traffic management and loop prevention for each VLAN—enabling better load balancing—it also means that the switch must manage multiple spanning tree instances. This can lead to increased resource utilization on the switch, including CPU and memory load, as each VLAN's topology has to be maintained and calculated independently. Therefore, as the number of VLANs increases, the management overhead can become significant, affecting the performance, especially in larger networks.

Identifying the nature of RPVST+'s operation helps highlight why this option accurately reflects a disadvantage of the protocol, especially in environments with many VLANs, where the cumulative load on the switch can become a critical consideration in network design.