H3C Technologies H3C S12500 Series Switches - Manual (Page 93)

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Step Command Remarks
2. Specify a standard for the
switch to use when calculating
the default path costs of its
ports.
stp pathcost-standard
{ dot1d-1998 | dot1t | legacy } Optional.
The default setting is legacy.
NOTE:
When calculating path cost for an aggregate interface, IEEE 802.1t takes into account the number of
Selected ports in its aggregation group, but IEEE 802.1d-1998 does not. The calculation formula of IEEE
802.1t is: Path Cost = 200,000,000/link speed (in 100 kbps), where link speed is the sum of the link
speed values of the Selected ports in the aggregation group.
Table 11 shows the mappings between the link speed and the path cost.
Table 11 Mappings between the link speed and the path cost
Link speed Port type
Path cost
IEEE
802.1d-1998
IEEE 802.1t Private standard
0 N/A 65535 200,000,000 200,000
10 Mbps
Single Port
100
2,000,000 2,000
Aggregate interface
containing 2 Selected
ports
1,000,000 1,800
Aggregate interface
containing 3 Selected
ports
666,666 1,600
Aggregate interface
containing 4 Selected
ports
500,000 1,400
100 Mbps
Single Port
19
200,000 200
Aggregate interface
containing 2 Selected
ports
100,000 180
Aggregate interface
containing 3 Selected
ports
66,666 160
Aggregate interface
containing 4 Selected
ports
50,000 140
1000 Mbps
Single Port
4
20,000 20
Aggregate interface
containing 2 Selected
ports
10,000 18
Aggregate interface
containing 3 Selected
ports
6666 16