Administrator Guide

Rapid Spanning Tree Protocol (RSTP)
Protocol Overview
The Dell Networking OS supports three other versions of spanning tree, as shown in the following table.
Table 84. Spanning Tree Versions Supported
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
Configuring Rapid Spanning Tree
Configuring RSTP is a two-step process.
1. Configure interfaces for Layer 2.
2. Enable the rapid spanning tree protocol.
Related Configuration Tasks
• Adding and Removing Interfaces
• Modifying Global Parameters
• Modifying Interface Parameters
• Configuring an EdgePort
• Prevent Network Disruptions with BPDU Guard
• Influencing RSTP Root Selection
• Enabling SNMP Traps for Root Elections and Topology Changes
• Configuring Fast Hellos for Link State Detection
• Flush MAC Addresses after a Topology Change
Important Points to Remember
• RSTP is disabled by default on the switch.
• The system supports only one Rapid Spanning Tree (RST) instance.
• All interfaces in virtual local area networks (VLANs) and all enabled interfaces in Layer 2 mode are automatically added to the RST
topology.
• Adding a group of ports to a range of VLANs sends multiple messages to the RSTP task, avoid using the range command. When
using the range command, Dell Networking recommends limiting the range to five ports and 40 VLANs.
RSTP and VLT
Virtual link trunking (VLT) provides loop-free redundant topologies and does not require RSTP.
RSTP can cause temporary port state blocking and may cause topology changes after link or node failures. Spanning tree topology
changes are distributed to the entire Layer 2 network, which can cause a network-wide flush of learned media access control (MAC) and
address resolution protocol (ARP) addresses, requiring these addresses to be re-learned. However, enabling RSTP can detect potential
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