The actual mode of spanning tree protocol runs
on the device. It can be one of the following:
pvstPlus -- PVST+ (Per VLAN Spanning Tree+ Protocol).
mistp -- MISTP (Multi Instance Spanning Tree Protocol).
mistpPvstPlus -- MISTP with the tunneling scheme
enabled for PVST+.
mst -- IEEE 802.1s Multiple Spanning Tree (MST)
with IEEE 802.1w Rapid Spanning Tree Protocol
(RSTP).
rapidPvstPlus -- IEEE 802.1w Rapid Spanning Tree
Protocol (RSTP) for all vlans in PVST+.
When the value of this MIB object gets changed, the
network connectivity would be affected and the
connectivity to this device would also be lost
temporarily.