H3C LS-3100-52P-OVS-H3 Operation Manual - page 265
1-29
Table 1-7 Link speed vs. path cost
Link speed
Duplex state
802.1d-1998
802.1t
Private standard
0 —
65535
200,000,000
200,000
10 Mbps
Single Port
Aggregate Link 2 Ports
Aggregate Link 3 Ports
Aggregate Link 4 Ports
100
100
100
100
2,000,000
1,000,000
666,666
500,000
2,000
1,800
1,600
1,400
100 Mbps
Single Port
Aggregate Link 2 Ports
Aggregate Link 3 Ports
Aggregate Link 4 Ports
19
19
19
19
200,000
100,000
66,666
50,000
200
180
160
140
1000 Mbps
Single Port
Aggregate Link 2 Ports
Aggregate Link 3 Ports
Aggregate Link 4 Ports
4
4
4
4
20,000
10,000
6,666
5,000
20
18
16
14
10 Gbps
Single Port
Aggregate Link 2 Ports
Aggregate Link 3 Ports
Aggregate Link 4 Ports
2
2
2
2
2,000
1,000
666
500
2
1
1
1
When calculating path cost for an aggregate interface, 802.1d-1998 does not take into account the
number of member ports in its aggregation group as 802.1t does. The calculation formula of 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 non-blocked ports in the aggregation group.
Configuring Path Costs of Ports
Follow these steps to configure the path cost of ports:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter Ethernet
interface view
or Layer-2
aggregate
interface view
interface interface-type
interface-number
Enter
interface view
or port group
view
Enter port
group view
port-group manual
port-group-name
Required
Use either command.
Configurations made in interface
view will take effect on the current
port only; configurations made in
port group view will take effect on all
ports in the port group.
Configure the path cost of the
port(s)
stp [ instance
instance-id ] cost cost
Required
By default, MSTP automatically
calculates the path cost of each port.