Reference Guide

Spanning Tree Protocol (STP) | 889
50
Spanning Tree Protocol (STP)
Spanning Tree Protocol (STP) is supported on the S5000 switch.
This chapter covers the following information:
• Protocol Overview
• Configuring Spanning Tree
• Configuring Interfaces for Layer 2 Mode
• Enabling Spanning Tree Protocol Globally
• Adding an Interface to the Spanning Tree Group
• Removing an Interface from the Spanning Tree Group
• Modifying Global Parameters
• Modifying Interface STP Parameters
• Enabling PortFast
• Preventing Network Disruptions with BPDU Guard
• BPDU Filtering
• BPDU Filtering
• STP Root Guard
• SNMP Traps for Root Elections and Topology Changes
• Configuring Spanning Trees as Hitless
• STP Loop Guard
• Displaying STP Guard Configuration
Protocol Overview
Spanning Tree Protocol (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 enables you to implement redundant paths, which can be
activated upon 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.