Which version of STP is used by Cisco switches that runs a separate spanning tree instance in each VLAN?

The correct answer is that Cisco switches use Per VLAN Spanning Tree (PVST) to run a separate spanning tree instance in each VLAN. This allows for the optimization of network paths and load balancing by enabling each VLAN to independently manage its topology.

PVST creates distinct spanning tree instances for each VLAN, which means that each VLAN can have its own active paths and can react independently to topology changes. This is particularly beneficial in networks with multiple VLANs as it allows for better utilization of the available paths and reduces unnecessary blocking of ports that might otherwise occur with a single spanning tree instance.

Each instance can react to failures or changes in the network topology without impacting other VLANs. This granularity provides enhanced flexibility and redundancy, making PVST an excellent choice for environments utilizing VLANs extensively.

Other versions of Spanning Tree Protocol (STP) do not replicate this behavior: Rapid STP, for example, provides faster convergence times compared to earlier versions but does not support multiple spanning tree instances per VLAN to the same extent as PVST. Techniques like Multiple Spanning Tree (MST) allow for multiple VLANs to share a single spanning tree instance but do not create distinct instances for each VLAN. Therefore, PVST is the most suitable answer when referring