H3C s3600 series Command Manual page 266

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Parameters
dot1d-1998: Uses the IEEE 802.1D-1998 standard to calculate the default path costs of ports.
dot1t: Uses the IEEE 802.1t standard to calculate the default path costs of ports.
legacy: Uses the proprietary standard to calculate the default path costs of ports.
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, a switch uses the legacy standard to calculate the default path costs of ports.
Table 1-8 Link speeds and the corresponding path costs
Link speed
0
10 Mbps
100 Mbps
1,000 Mbps
10 Gbps
Normally, when a port operates in full-duplex mode, the corresponding path cost is slightly less than that
when the port operates in half-duplex mode.
When the path cost of an aggregated link is calculated, the 802.1D-1998 standard does not take the
number of the ports on the aggregated link into account, whereas the 802.1T standard does. The
following formula is used to calculate the path cost of an aggregated link:
Path cost = 200,000 / link speed,
In this formula, the link speed is the sum of the speeds of the unblocked ports on the aggregated link,
which is measured in 100 Kbps.
Operating mode
(half-/full-duplex)
—
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
802.1D-1998 IEEE 802.1t
65,535 200,000,000
100 200,000
95 1,000,000
95 666,666
95 500,000
19 200,000
15 100,000
15 66,666
15 50,000
4 200,000
3 10,000
3 6,666
3 5,000
2 200,000
1 1,000
1 666
1 500
1-37
Proprietary
standard
200,000
2,000
1,800
1,600
1,400
200
180
160
140
20
18
16
14
2
1
1
1