617
In the calculation of the path cost value of an aggregated link, 802.1D-1998 does
not take into account the number of ports in the aggregated link. Whereas,
802.1T takes the number of ports in the aggregated link into account. The
calculation formula 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
aggregated link.
Examples # Configure the device to calculate the default path cost for ports based on IEEE
802.1D-1998.
<Sysname> system-view
[Sysname] stp pathcost-standard dot1d-1998
# Configure the device to calculate the default path cost for ports based on IEEE
802.1t.
<Sysname> system-view
[Sysname] stp pathcost-standard dot1t
stp point-to-point
Syntax stp point-to-point { auto | force-false | force-true }
undo stp point-to-point
View Ethernet interface view, port group view
100Mbps Single Port
Aggregated
Link 2 Ports
Aggregated
Link 3 Ports
Aggregated
Link 4 Ports
19
19
19
19
200,000
100,000
66,666
50,000
200
180
160
140
1000Mbps Single Port
Aggregated
Link 2 Ports
Aggregated
Link 3 Ports
Aggregated
Link 4 Ports
4
4
4
4
20,000
10,000
6,666
5,000
20
18
16
14
10Gbps Single Port
Aggregated
Link 2 Ports
Aggregated
Link 3 Ports
Aggregated
Link 4 Ports
2
2
2
2
2,000
1,000
666
500
2
1
1
1
Table 110 Link speed vs. path cost
Link speed Duplex state 802.1D-1998 IEEE 802.1t Private standard
