Administrator Guide

• Enable Multiple Spanning Tree Globally
• Adding and Removing Interfaces
• Creating Multiple Spanning Tree Instances
• Influencing MSTP Root Selection
• Interoperate with Non-Dell Bridges
• Changing the Region Name or Revision
• Modifying Global Parameters
• Modifying the Interface Parameters
• Configuring an EdgePort
• Flush MAC Addresses after a Topology Change
• MSTP Sample Configurations
• Debugging and Verifying MSTP Configurations
Spanning Tree Variations
The Dell Networking OS supports four variations of spanning tree, as shown in the following table.
Table 60. Spanning Tree Variations
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
Implementation Information
MSTP is implemented as follows in Dell Networking OS:
• The Dell Networking OS MSTP implementation is based on IEEE 802.1Q-2003 and interoperates only with bridges that also use this
standard implementation.
• MSTP is compatible with STP and RSTP.
• Dell Networking OS supports only one MSTP region.
• When you enable MSTP, all ports in Layer 2 mode participate in MSTP.
• You can configure 64 MSTIs including the default instance 0 (CIST).
Configure Multiple Spanning Tree Protocol
Configuring multiple spanning tree is a four-step process.
1 Configure interfaces for Layer 2.
2 Place the interfaces in VLANs.
3 Enable the multiple spanning tree protocol.
4 Create multiple spanning tree instances and map VLANs to them.
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Multiple Spanning Tree Protocol (MSTP)