Users Guide

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
To remove a Layer 2 interface from the spanning tree topology, enter the no spanning-tree 0 command.
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 88. STP Default Values
STP Parameters Default Value
Forward Delay 15 seconds
Hello Time 2 seconds
Max Age 20 seconds
Port Cost
• 100-Mb/s Ethernet interfaces
• 1-Gigabit Ethernet interfaces
• 10-Gigabit Ethernet interfaces
• Port Channel with 100 Mb/s Ethernet interfaces
• Port Channel with 1-Gigabit Ethernet interfaces
• Port Channel with 10-Gigabit Ethernet
interfaces
• 19
• 4
• 2
• 18
• 3
• 1
Port Priority 8
• Change the forward-delay parameter (the wait time before the interface enters the Forwarding state).
PROTOCOL SPANNING TREE mode
forward-delay seconds
Spanning Tree Protocol (STP) 1080