Administrator Guide

• Assign a bridge priority.
PROTOCOL PVST mode
vlan bridge-priority
The range is from 0 to 61440.
The default is 32768.
Example of the show spanning-tree pvst vlan Command
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
BPDU sent 449, received 0
The port is not in the Edge port mode, bpdu filter is disabled
Port 450 (TenGigabitEthernet 5/41) is disabled Discarding
Port path cost 2000, Port priority 128, Port Identifier 128.450
Designated root has priority 32768, address 001e.c9f1.00:f3
Designated bridge has priority 32768, address 001e.c9f1.00:f3
Designated port id is 128.450 , designated path cost 0
Number of transitions to forwarding state 0
BPDU sent 0, received 0
The port is not in the Edge port mode, bpdu filter is disabled
Port 459 (TenGigabitEthernet 5/50) is designated Forwarding
Port path cost 2000, Port priority 128, Port Identifier 128.459
Designated root has priority 32768, address 001e.c9f1.00:f3
Designated bridge has priority 32768, address 001e.c9f1.00:f3
Designated port id is 128.459 , designated path cost 0
Number of transitions to forwarding state 1
BPDU sent 457, received 0
The port is not in the Edge port mode, bpdu filter is disable
Modifying Global PVST+ Parameters
The root bridge sets the values for forward-delay and hello-time, and overwrites the values set on other PVST+ bridges.
• Forward-delay — the amount of time an interface waits in the Listening state and the Learning state before it transitions to the
Forwarding state.
• Hello-time — the time interval in which the bridge sends bridge protocol data units (BPDUs).
• Max-age — the length of time the bridge maintains conguration information before it refreshes that information by
recomputing the PVST+ topology.
To change PVST+ parameters on the root bridge, use the following commands.
Per-VLAN Spanning Tree Plus (PVST+)
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