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Table Of Contents
Spanning Tree Protocol (STP)
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
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
Prevent Network Disruptions with BPDU Guard
Global BPDU Filtering
Interface BPDU Filtering
Selecting STP Root
STP Root Guard
Enabling SNMP Traps for Root Elections and Topology Changes
Configuring Spanning Trees as Hitless
STP Loop Guard
Displaying STP Guard Configuration
Protocol Overview
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 STP, can cause
unnecessarily high switch CPU utilization and memory consumption.
Dell Networking OS supports three other variations of spanning tree, as shown in the following table.
Table 99. 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
Configure Spanning Tree
Configuring spanning tree is a two-step process.
Configuring Interfaces for Layer 2 Mode
Enabling Spanning Tree Protocol Globally
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858 Spanning Tree Protocol (STP)