Administrator Guide

Spanning Tree Variations
The Dell Networking operating system (OS) supports four variations of spanning tree, as shown in the following table.
Table 42. Spanning Tree Variations
Dell Networking Term IEEE Specication
Spanning Tree Protocol (STP) 802 .1d
Rapid Spanning Tree Protocol (RSTP) 802 .1w
Multicast Source Discovery Protocol (MSDP) 802 .1s
Per-VLAN Spanning Tree Plus (PVST+) Third Party
Implementation Information
The following describes the MSTP implementation information.
• 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.
• The Dell Networking OS supports only one MSTP region.
• When you enable MSTP, all ports in Layer 2 mode participate in MSTP.
• On the MXL switch, you can congure 64 MSTIs including the default instance 0 (CIST).
Congure Multiple Spanning Tree Protocol
Conguring multiple spanning tree is a four-step process.
1. Congure 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.
Related Conguration Tasks
The following are the related conguration tasks for MSTP.
• Creating Multiple Spanning Tree Instances
• Inuencing MSTP Root Selection
• Interoperate with Non-Dell Networking OS Bridges
• Enable BPDU Filtering Globally
• Modifying Global Parameters
• Conguring an EdgePort
• Flush MAC Addresses after a Topology Change
• Debugging and Verifying MSTP Congurations
• Prevent Network Disruptions with BPDU Guard
• SNMP Traps for Root Elections and Topology Changes
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Multiple Spanning Tree Protocol (MSTP)