Cisco Systems OL-8241-02 Manual De Usuario

The path cost is the contribution of the interface to the vast path cost towards the 
spanning-tree root. Use the bridge pathcost command to set the spanning-tree 
path cost for an Ethernet interface or for a trunked Ethernet interface. Enter an 
integer from 1 to 65535. The default is dynamically configured based on the 
interface speed.

For example, to set a path cost of 9 for e7 on the CSS 11501, enter:

(config-if[e7])# bridge pathcost 9

For example, to set a path cost of 2 for the I/O module in slot 1, Ethernet port 1, 
in VLAN3, enter:

(config-if-vlan[1/1-3])# bridge pathcost 2

To restore the default path cost, enter:

(config-if-vlan[1/1-3])# no bridge pathcost

To set the spanning-tree bridge port priority for an Ethernet interface or for a 
trunked Ethernet interface, se the bridge port-priority command. If the CSS has 
a bridge port priority that is lower than all other switches, it will be automatically 
selected by the other switches as the root switch. Enter an integer from 0 to 255. 
The default is 128.

For example, to set a bridge port priority of 100 for e7 on the CSS 11501, enter:

(config-if[e7])# bridge port-priority 100

For example, to set a bridge port priority of 100 for the I/O module in slot 1, 
Ethernet port 1, in VLAN3, enter:

(config-if-vlan[1/1-3])# bridge port-priority 100

To restore the default port priority of 128, enter:

(config-if-vlan[1/1-3])# no bridge port-priority