H3C LS-3100-52P-OVS-H3 Operation Manual page 265

Table 1-7 Link speed vs. path cost
Link speed
0 —
Single Port
Aggregate Link 2 Ports
10 Mbps
Aggregate Link 3 Ports
Aggregate Link 4 Ports
Single Port
Aggregate Link 2 Ports
100 Mbps
Aggregate Link 3 Ports
Aggregate Link 4 Ports
Single Port
Aggregate Link 2 Ports
1000 Mbps
Aggregate Link 3 Ports
Aggregate Link 4 Ports
Single Port
Aggregate Link 2 Ports
10 Gbps
Aggregate Link 3 Ports
Aggregate Link 4 Ports
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...
Enter system view
Enter Ethernet
interface view
Enter
or Layer-2
interface view
aggregate
or port group
interface view
view
Enter port
group view
Configure the path cost of the
port(s)
Duplex state 802.1d-1998
65535
100
100
100
100
19
19
19
19
4
4
4
4
2
2
2
2
Use the command...
system-view
interface interface-type
interface-number
port-group manual
port-group-name
stp [ instance
instance-id ] cost cost
1-29
802.1t Private standard
200,000,000 200,000
2,000,000 2,000
1,000,000 1,800
666,666 1,600
500,000 1,400
200,000 200
100,000 180
66,666 160
50,000 140
20,000 20
10,000 18
6,666 16
5,000 14
2,000 2
1,000 1
666 1
500 1
Remarks
—
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.
Required
By default, MSTP automatically
calculates the path cost of each port.