Users Guide

Dell Networking Term IEEE Specification
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
Related Configuration Tasks
• Adding an Interface to the Spanning Tree Group
• Modifying Global Parameters
• Modifying Interface STP Parameters
• Enabling PortFast
• Prevent Network Disruptions with BPDU Guard
• STP Root Guard
• Enabling SNMP Traps for Root Elections and Topology Changes
Important Points to Remember
• STP is disabled by default.
• The Dell Networking OS supports only one spanning tree instance (0). For multiple instances, enable the
multiple spanning tree protocol (MSTP) or per-VLAN spanning tree plus (PVST+). You may only enable
one flavor of spanning tree at any one time.
• All ports in virtual local area networks (VLANs) and all enabled interfaces in Layer 2 mode are
automatically added to the spanning tree topology at the time you enable the protocol.
• To add interfaces to the spanning tree topology after you enable STP, enable the port and configure it
for Layer 2 using the switchport command.
• The IEEE Standard 802.1D allows 8 bits for port ID and 8 bits for priority. The 8 bits for port ID provide
port IDs for 256 ports.
Spanning Tree Protocol (STP) 1075