404 | Per-VLAN Spanning Tree Plus (PVST+)
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The Dell Force10 operating software (FTOS) supports three other variations of spanning tree (Table 23-1).
Implementation Information
• The FTOS implementation of PVST+ is based on RPVST.
• The FTOS implementation of PVST+ uses IEEE 802.1s costs as the default costs (Table 23-2). Other 
implementations use IEEE 802.1d costs as the default costs. If you are using Dell Force10 systems in a 
multi-vendor network, verify that the costs are values you intended.
• You can enable PVST+ on 255 VLANs.
 
Configuring Per-VLAN Spanning Tree Plus
Configuring PVST+ is a four-step process:
1. Configure interfaces for Layer 2.
2. Place the interfaces in VLANs.
3. Enable PVST+. 
4. Optionally, for load balancing, select a non-default bridge-priority for a VLAN. 
Related Configuration Tasks
• Modify Global PVST+ Parameters
• Enable BPDU Filtering globally
• Configure an EdgePort
• Flush MAC Addresses after a Topology Change
• Preventing Network Disruptions with BPDU Guard
• SNMP Traps for Root Elections and Topology Changes
• PVST+ in Multi-vendor Networks
• PVST+ Extended System ID
• PVST+ Sample Configurations
Table 23-1.  FTOS Supported Spanning Tree Protocols
Dell Force10 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