This object set spanning-tree mode. stp - The Spanning Tree Protocol(IEEE 802.1D) is a network protocol that ensures a loop-free topology for any bridged Ethernet local area network. rstp - Rapid Spanning Tree Protocol(IEEE 802.1w), an enhancement to Spanning Tree Protocol. RSTP provides significantly faster spanning tree convergence after a topology change, introducing new convergence behaviors and bridge port roles to do this. RSTP was designed to be backwards-compatible with standard STP.