DELL N3000 User Manual

Switch Feature Overview

For information about configuring Spanning Tree Protocol features, see 

"Configuring the Spanning Tree Protocol" on page 715.

Spanning Tree Protocol (IEEE 802.1D) is a standard requirement of Layer 2 

switches that allows bridges to automatically prevent and resolve L2 

forwarding loops.

The STP feature supports a variety of per-port settings including path cost, 

priority settings, Port Fast mode, STP Root Guard, Loop Guard, TCN Guard, 

and Auto Edge. These settings are also configurable per-LAG.

Rapid Spanning Tree Protocol (RSTP) detects and uses network topologies to 

enable faster spanning tree convergence after a topology change, without 

creating forwarding loops. The port settings supported by STP are also 

supported by RSTP.

Multiple Spanning Tree (MSTP) operation maps VLANs to spanning tree 

instances. Packets assigned to various VLANs are transmitted along different 

paths within MSTP Regions (MST Regions). Regions are one or more 

interconnected MSTP bridges with identical MSTP settings. The MSTP 

standard lets administrators assign VLAN traffic to unique paths.
The switch supports IEEE 802.1Q-2005, which is a version of corrects 

problems associated with the previous version, provides for faster transition-

to-forwarding, and incorporates new features for a port (restricted role and 

restricted TCN).