Enable PVST+
When you enable PVST+, FTOS instantiates STP on each active VLAN. To enable PVST+ globally:
Step
Task
1
Enter PVST context.
2
Enable PVST+.
Disable PVST+
Task
Disable PVST+ globally.
Disable PVST+ on an interface, or remove a PVST+
parameter configuration.
Display your PVST+ configuration by entering the command
context, as shown in fig.
Figure 40-2. Display the PVST+ Configuration
Force10_E600(conf-pvst)#show config verbose
!
protocol spanning-tree pvst
no disable
vlan 100 bridge-priority 4096
Influence PVST+ Root Selection
In
Figure
40-1, all VLANs use the same forwarding topology because R2 is elected the root, and all
GigabitEthernet ports have the same cost.
different forwarding topology is generated for each VLAN. This behavior demonstrates how you can use
PVST+ to achieve load balancing.
Command Syntax
protocol spanning-tree pvst
no disable
Command Syntax
disable
no spanning-tree pvst
show config
Figure 40-3
changes the bridge priority of each bridge so that a
Command Mode
PROTOCOL PVST
PROTOCOL PVST
Command Mode
PROTOCOL PVST
INTERFACE
from PROTOCOL PVST
Per-VLAN Spanning Tree Plus | 837