Dell PowerEdge FN I/O Module Configuration Guide 9.10(0.0)

PDF

Protocol Overview

STP is a Layer 2 protocol — specified by IEEE 802.1d — that eliminates loops in a bridged topology by enabling only a single path through the network.

By eliminating loops, the protocol improves scalability in a large network and allows you to implement redundant paths, which can be activated after the failure of active paths. Layer 2 loops, which can occur in a network due to poor network design and without enabling protocols like xSTP, can cause unnecessarily high switch CPU utilization and memory consumption.

The Dell Networking OS supports three other variations of spanning tree, as shown in the following table.

Table 1. Dell Networking OS Supported Spanning Tree Protocols
Dell Networking Term	IEEE Specification
Spanning Tree Protocol (STP)	802.1d
Rapid Spanning Tree Protocol (RSTP)	802.1w
Multiple Spanning Tree Protocol (MSTP)	802.1s
Per-VLAN Spanning Tree Plus (PVST+)	Third Party