Reference Guide

896 | Spanning Tree Protocol (STP)
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To change STP global parameters:
View the current values for global parameters using the
show spanning-tree 0 command from EXEC
privilege mode. Refer to the second example in Enabling Spanning Tree Protocol Globally.
Modifying Interface STP Parameters
You can set the port cost and port priority values of interfaces in Layer 2 mode.
• Port cost is a value that is based on the interface type. The greater the port cost, the less likely the port
will be selected to be a forwarding port.
• Port priority influences the likelihood that a port will be selected to be a forwarding port in case that
several ports have the same port cost.
The default values are listed in Table 50-2.
To change the port cost or priority of an interface:
View the current values for interface parameters using the
show spanning-tree 0 command from EXEC
privilege mode.Refer to the second example in Enabling Spanning Tree Protocol Globally.
Task Command Syntax Command Mode
Change the forward-delay parameter (the wait time before the
interface enters the forwarding state).
Range: 4 to 30. Default: 15 seconds
forward-delay seconds PROTOCOL
SPANNING TREE
Change the hello-time parameter (the BPDU transmission interval).
Note: With large configurations (especially those with more
ports) Dell Networking recommends that you increase the
hello-time.
Range: 1 to 10. Default: 2 seconds
hello-time seconds PROTOCOL
SPANNING TREE
Change the max-age parameter (the refresh interval for configuration
information that is generated by recomputing the Spanning Tree
topology).
Range: 6 to 40. Default: 20 seconds
max-age seconds PROTOCOL
SPANNING TREE
Task Command Syntax Command Mode
Change the port cost of an interface.
Range: 0 to 65535
Default: see Table 50-2.
spanning-tree 0 cost cost INTERFACE
Change the port priority of an interface.
Range: 0 to 15
Default: 8
spanning-tree 0 priority
priority-value
INTERFACE