3Com 8807 Configuration Manual page 143

The actual rate counts.
2 Calculating the path cost
Table 121 details the correspondence between the rate range and the path cost
values of the ports.
Table 121 Correspondence between the rate range and the PATH cost values
Rate range
[0, 10]
(10, 100]
(100,1000]
(1000,10000]
> 10000
3Com's legacy calculation standard
1 Calculating the rate
Aggregation port
■
The rate of the primary port in an aggregation group is determined by the sum of
the port rates in this group. No calculation is performed for secondary port.
Non-aggregation port
■
The actual rate counts, but the rate is 0 if the port is down.
2 Calculating the path cost
Table 122 details the correspondence between the rate range and the value range
of the path cost of the ports.
Table 122 Correspondence between the rate range and PATH cost range
Rate range
[0, 100]
(100,1000]
(1000,10000]
> 10000
You can specify the intended standard by using the following commands.
Perform the following configuration in system view.
Configuring MSTP
PATH cost value
99 (for full-duplex port)
95 (for aggregation port)
100 (default)
18 (for full-duplex port)
15 (for aggregation port)
19 (default)
3 (for aggregation port)
4 (default)
1 (for aggregation port)
2 (default)
1
PATH cost range
2200 to (20 × rate)
220 to the integer of [(0.2 × rate)]
22 to the integer of [(0.002 × rate)]
1
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