3.12.5. spanning-tree mst cost

Syntax

spanning-tree mst instance-id cost cost

no spanning-tree mst instance-id cost cost

Parameter

instance-id Specify the instance ID. The valid range is from 0 to 15.

cost Specify the path cost for the interfaces on the specific MSTP instance. For the long path cost method, its valid range is from 0 to 200000000; and the valid range is from 0 to 65535 for the short path cost method. The value 0 indicates AUTO, which the port path cost is determined by the port speed and the path cost method.

Default

The default port path cost is 0, and it is determined by the port speed and the path cost method (long or short).

Interface Long Short Gigabit Ethernet(1000Mbps)20000 4 Fast Ethernet (100Mbps) 200000 19 Ethernet (10Mbps) 2000000 100

Mode

Interface Configuration

Usage

To configure the path cost for MSTP calculations, use the command spanning-tree mst cost in the Interface Configuration mode. If the loop occurs, the MSTP considers the path cost when selecting the interface into the Forwarding state. For the default configuration, use the no form of the command. When configuring the path cost on the CIST (instance 0), it is equal to the command spanning-tree cost in the Interface Configuration mode.

Example

The following example configures the path cost of interface fa1 on the instance 1 to 30000.

Switch(config)# interface gi1
Switch(config-if)# spanning-tree mst 1 cost 30000