Spanning Tree Protocol (Stp); Protocol Overview - Dell C9000 Series Networking Configuration Manual

Spanning Tree Protocol (STP)

The 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.
Topics:
•

Protocol Overview

• Configure Spanning Tree
• Important Points to Remember
• Configuring Interfaces for Layer 2 Mode
• Enabling Spanning Tree Protocol Globally
• Adding an Interface to the Spanning Tree Group
• Modifying Global Parameters
• Modifying Interface STP Parameters
• Enabling PortFast
• Preventing Network Disruptions with BPDU Guard
• Selecting STP Root
• STP Root Guard
• Enabling SNMP Traps for Root Elections and Topology Changes
• STP Loop Guard
• Displaying STP Guard Configuration
Protocol Overview
By eliminating loops, STP 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 system supports three other versions of spanning tree, as shown in the following table.
Table 87. Dell Networking OS Supported Spanning Tree Protocols
Dell Networking Term
Spanning Tree Protocol (STP)
Rapid Spanning Tree Protocol (RSTP)
Multiple Spanning Tree Protocol (MSTP)
IEEE Specification
802.1d
802.1w
802.1s
Spanning Tree Protocol (STP)
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