3Com 5500-EI PWR, Справочное руководство

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<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 .
Table 1-8 Link speeds and the corresponding path costs
Link speed Duplex state
Path cost in
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