- Rapid PVST+
Explanation: MST is the Cisco implementation of MSTP, an IEEE standard protocol that provides up to 16 instances of RSTP and combines many VLANs with the same physical and logical topology into a common RSTP instance. Each instance supports PortFast, BPDU guard, BPDU filter, root guard, and loop guard. STP and RSTP assume only one spanning-tree instance for the entire bridged network, regardless of the number of VLANs. PVST+ provides a separate 802.1D spanning-tree instance for each VLAN that is configured in the network.