Adding an Interface to the Spanning Tree Group
To add a Layer 2 interface to the spanning tree topology, use the following command.
• Enable spanning tree on a Layer 2 interface.
INTERFACE mode
spanning-tree 0
Removing an Interface from the Spanning Tree Group
To remove a Layer 2 interface from the spanning tree topology, use the following command.
• Disable spanning tree on a Layer 2 interface.
INTERFACE mode
no spanning-tree 0
Modifying Global Parameters
You can modify the spanning tree parameters. The root bridge sets the values for forward-delay, hello-
time, and max-age and overwrites the values set on other bridges participating in STP.
NOTE: Dell Networking recommends that only experienced network administrators change the
spanning tree parameters. Poorly planned modification of the spanning tree parameters can
negatively affect network performance.
The following table displays the default values for STP.
Table 68. STP Default Values
STP Parameters Default Value
Forward Delay 15 seconds
Hello Time 2 seconds
Max Age 20 seconds
Port Cost
• 40-Gigabit Ethernet interfaces
• 10-Gigabit Ethernet interfaces
• Port Channel with 40-Gigabit Ethernet
interfaces
• Port Channel with 10-Gigabit Ethernet
interfaces
• 1
• 2
• 1
• 1
Port Priority 8
• Change the forward-delay parameter (the wait time before the interface enters the Forwarding
state).
Spanning Tree Protocol (STP) 915