Reference Guide
4. Optionally, for load balancing, select a nondefault bridge-priority for a VLAN.
Related Configuration Tasks
● Modifying Global PVST+ Parameters
● Modifying Interface PVST+ Parameters
● Configuring an EdgePort
● Flush MAC Addresses after a Topology Change
● Prevent Network Disruptions with BPDU Guard
● Enabling SNMP Traps for Root Elections and Topology Changes
● PVST+ in Multi-Vendor Networks
● Enabling PVST+ Extended System ID
● PVST+ Sample Configurations
Enabling PVST+
When you enable PVST+, the system instantiates STP on each active VLAN.
1. Enter PVST context.
PROTOCOL PVST mode
protocol spanning-tree pvst
2. Enable PVST+.
PROTOCOL PVST mode
no disable
Disabling PVST+
To disable PVST+ globally or on an interface, use the following commands.
● Disable PVST+ globally.
PROTOCOL PVST mode
disable
● Disable PVST+ on an interface, or remove a PVST+ parameter configuration.
INTERFACE mode
no spanning-tree pvst
To display your PVST+ configuration, use the show config command from PROTOCOL PVST mode.
Dell_E600(conf-pvst)#show config verbose
!
protocol spanning-tree pvst
no disable
vlan 100 bridge-priority 4096
Influencing PVST+ Root Selection
As shown in the previous PVST+ illustration, all VLANs use the same forwarding topology because R2 is elected the root, and all
TengigabitEthernet ports have the same cost.
The following per-VLAN spanning tree illustration changes the bridge priority of each bridge so that a different forwarding
topology is generated for each VLAN. This behavior demonstrates how you can use PVST+ to achieve load balancing.
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Per-VLAN Spanning Tree Plus (PVST+)