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Figure 99. Load Balancing with PVST+
The bridge with the bridge value for bridge priority is elected root. Because all bridges use the default priority (until configured
otherwise), the lowest MAC address is used as a tie-breaker. To increase the likelihood that a bridge is selected as the STP root,
assign bridges a low non-default value for bridge priority.
To assign a bridge priority, use the following command.
● Assign a bridge priority.
PROTOCOL PVST mode
vlan bridge-priority
The range is from 0 to 61440.
The default is 32768.
To display the PVST+ forwarding topology, use the show spanning-tree pvst [vlan vlan-id] command from EXEC
Privilege mode.
Dell(conf-if-te-5/41)#do show spanning-tree pvst vlan 2
VLAN 2
Root Identifier has priority 32768, Address 001e.c9f1.00f3
Root Bridge hello time 2, max age 20, forward delay 15
Bridge Identifier has priority 32768, Address 001e.c9f1.00f3
Configured hello time 2, max age 20, forward delay 15
Bpdu filter disabled globally
We are the root of VLAN 2
Current root has priority 32768, Address 001e.c9f1.00f3
Number of topology changes 2, last change occured 00:14:39 ago on Po 23
Port 24 (Port-channel 23) is designated Forwarding
Port path cost 1600, Port priority 128, Port Identifier 128.24
Designated root has priority 32768, address 001e.c9f1.00:f3
Designated bridge has priority 32768, address 001e.c9f1.00:f3
Designated port id is 128.24 , designated path cost 0
Number of transitions to forwarding state 1
600
Per-VLAN Spanning Tree Plus (PVST+)