Stp Pathcost-Standard - 3Com 5500-EI PWR Reference Manual

<Sysname> system-view
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[Sysname]stp interface Ethernet1/0/1 no-agreement-check

stp pathcost-standard

Syntax
stp pathcost-standard { dot1d-1998 | dot1t | legacy }
undo stp pathcost-standard
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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
0 —
Half-duplex/Full-duplex
Aggregated link 2 ports
10 Mbps
Aggregated link 3 ports
Aggregated link 4 ports
Half-duplex/Full-duplex
Aggregated link 2 ports
100 Mbps
Aggregated link 3 ports
Aggregated link 4 ports
Full-duplex
Aggregated link 2 ports
1,000 Mbps
Aggregated link 3 ports
Aggregated link 4 ports
Duplex state
65,535
100
95
95
95
19
15
15
15
4
3
3
3
1-29
Path cost in Path cost in
802.1d-1998 IEEE 802.1t
standard standard
200,000,000
200,000
1,000,000
666,666
500,000
200,000
100,000
66,666
50,000
200,000
10,000
6,666
5,000
Path cost in
private
standard
200,000
2,000
1,800
1,600
1,400
200
180
160
140
20
18
16
14