Modifying Global Pvst+ Parameters - Dell Z9000 Configuration Manual

Root Identifier has priority 4096, Address 0001.e80d.b6d6
Root Bridge hello time 2, max age 20, forward delay 15
Bridge Identifier has priority 4096, Address 0001.e80d.b6d6
Configured hello time 2, max age 20, forward delay 15
We are the root of VLAN 100
Current root has priority 4096, Address 0001.e80d.b6d6
Number of topology changes 5, last change occurred 00:34:37 ago on Gi 1/32
Port 375 (GigabitEthernet 1/22) is designated Forwarding
Port path cost 20000, Port priority 128, Port Identifier 128.375
Designated root has priority 4096, address 0001.e80d.b6:d6
Designated bridge has priority 4096, address 0001.e80d.b6:d6
Designated port id is 128.375 , designated path cost 0
Number of transitions to forwarding state 2
BPDU sent 1159, received 632
The port is not in the Edge port mode
Port 385 (GigabitEthernet 1/32) is designated Forwarding
Port path cost 20000, Port priority 128, Port Identifier 128.385
Designated root has priority 4096, address 0001.e80d.b6:d6
Designated bridge has priority 4096, address 0001.e80d.b6:d6
Designated port id is 128.385 , designated path cost 0

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 configuration information before it refreshes that
information by recomputing the PVST+ topology.
To change PVST+ parameters on the root bridge, use the following commands.
• Change the forward-delay parameter.
PROTOCOL PVST mode
vlan forward-delay
The range is from 4 to 30.
The default is 15 seconds.
• Change the hello-time parameter.
PROTOCOL PVST mode
vlan hello-time
NOTE: With large configurations (especially those configurations with more ports), Dell
Networking recommends increasing the hello-time.
The range is from 1 to 10.
The default is 2 seconds.
• Change the max-age parameter.
Per-VLAN Spanning Tree Plus (PVST+)
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