R1-SW24L2B User’s Manual
13-24
Configuring the Path Cost
When spanning tree is configured, if there are over two paths, lower cost of the path is selected.
By default, path cost of a port is decided by physical link speed as follows:
y
Ethernet link (10Mbps): 2,000,000
y Fast Ethernet link (100Mbps): 2000,000
y Gigabit Ethernet link (1Gbps): 20,000
If you want to rarely use a port that is high speed because of a lack of stability or other reasons,
you specify high path cost of the port.
To configure the path cost for the specified port, use the following commands.
Table 13-12 Configuring the path cost
Command Task
configure terminal
1. Enter Global configuration mode.
port <port-type>
<slot>/<port>
pathcost <path-cost>
2. Set the path cost for a specific port..
y <port-type>: The type of Ethernet port.
- fastethernet: Fast Ethernet port
- gigabitethernet
: Gigabit Ethernet port
y <slot>/<port> slot/port number of a port
y <path-cost> path cost of a port (1 ~ 200000000).
end
3. Return to Privileged mode.
show stp port <port-
type> <slot>/<port>
4. Verify the configuration result.
The following example shows how to set the path cost for the Fast Ethernet port 2/1 to 20000:
(config)# port fastethernet 2/1 pathcost 20000
(config)# end
# show stp port fastethernet 2/1
Link S tate : up
Protocol Operation: enabled
Pathcost Encoding: 32bit
Port Number(logical): 129
Port Priority: 0x8
Designated Path Cost: 20000
AdminE dge: false
