3com 5500-ei pwr Reference Guide
1-29
<Sysname> system-view
System View: return to User View with Ctrl+Z.
[Sysname]stp interface Ethernet1/0/1 no-agreement-check
stp pathcost-standard
Syntax
stp pathcost-standard { dot1d-1998 | dot1t | legacy }
undo stp pathcost-standard
View
System view
Parameters
dot1d-1998: The device calculates the default path cost for ports based on IEEE 802.1d-1998.
dot1t: The device calculates the default path cost for ports based on IEEE 802.1t.
legacy: The device calculates the default path cost for ports based on a private standard.
Description
Use the stp pathcost-standard command to set the standard to be used to calculate the default path
costs of the links connected to the switch.
Use the undo stp pathcost-standard command to specify to use the default standard.
By default, the device calculates the default path cost for ports based on a private standard. STP uses
path costs to indicate the quality of links. A smaller path cost indicates a higher link quality. The path
cost of a port is related to the rate of the link connecting the port. The higher the link rate, the smaller the
path cost. The path cost of a port may vary when different standards are used to calculate it. For details,
see
Table 1-8 Link speeds and the corresponding path costs
Link speed
Duplex state
Path cost in
802.1d-1998
802.1d-1998
standard
Path cost in
IEEE 802.1t
standard
Path cost in
private
standard
0 —
65,535
200,000,000
200,000
10 Mbps
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
100
95
95
95
200,000
1,000,000
666,666
500,000
2,000
1,800
1,600
1,400
100 Mbps
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
19
15
15
15
200,000
100,000
66,666
50,000
200
180
160
140
1,000 Mbps
Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
4
3
3
3
200,000
10,000
6,666
5,000
20
18
16
14