STP - Multiple Spanning Tree (MST)

Multiple Spanning Tree (MST) is a version of Spanning Tree Protocol (STP) that is used to map multiple VLANs to the same spanning tree instance. This way,  instead of calculating a spanning tree for each VLAN, we can assign multiple VLANs to a single instance, minimizing the requirement of calculating a separate spanning tree for each VLAN.

This is especially useful in situations where there are an extensively large number of VLANs (dozens or even hundreds). This is done by mapping groups of VLANs together.

In contrast, Per VLAN Spanning Tree plus (PVST+) protocol requires the creation of a separate spanning tree for each VLAN, consuming CPU cycles, and system memory and resources for each one.

MST is compatible with PVST+.