Command Line Interface
4-164
4
spanning-tree cost
This command configures the spanning tree path cost for the specified interface.
Use the no form to restore the default.
Syntax
spanning-tree cost cost
no spanning-tree cost
cost - The path cost for the port. (Range: 1-200,000,000))
The recommended range is:
• Ethernet: 200,000-20,000,000
• Fast Ethernet: 20,000-2,000,000
• Gigabit Ethernet: 2,000-200,000
Default Setting
• Ethernet – half duplex: 2,000,000; full duplex: 1,000,000; trunk: 500,000
• Fast Ethernet – half duplex: 200,000; full duplex: 100,000; trunk: 50,000
• Gigabit Ethernet – full duplex: 10,000; trunk: 5,000
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
• This command is used by the Spanning Tree Algorithm to determine the best
path between devices. Therefore, lower values should be assigned to ports
attached to faster media, and higher values assigned to ports with slower
media.
• Path cost takes precedence over port priority.
• When the spanning-tree pathcost method (page 4-158) is set to short, the
maximum value for path cost is 65,535.
Example
spanning-tree port-priority
This command configures the priority for the specified interface. Use the no form to
restore the default.
Syntax
spanning-tree port-priority priority
no spanning-tree port-priority
priority - The priority for a port. (Range: 0-240, in steps of 16)
Console(config)#interface ethernet 1/5
Console(config-if)#spanning-tree cost 50
Console(config-if)#