Operation Manual – MSTP
H3C S3100 Series Ethernet Switches
Chapter 1 MSTP Configuration
1-38
Table 1-28
Specify the standard for calculating path costs
Operation
Command
Description
Enter system view
system-view
—
Specify the standard for
calculating the default
path costs of the links
connected to the ports of
the switch
stp pathcost-standard
{
dot1d-1998
|
dot1t
|
legacy
}
Optional
By default, the legacy
standard is used to
calculate the default path
costs of ports.
Table 1-29
Transmission speeds and the corresponding path costs
Transmiss
ion speed
Operation mode
(half-/full-duplex)
802.1D-1998
IEEE 802.1t
Proprietary
standard
0 —
65,535
200,000,000
200,000
10 Mbps
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
100
95
95
95
2,000,000
1,000,000
666,666
500,000
2,000
1,800
1,600
1,400
100 Mbps
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
19
15
15
15
200,000
100,000
66,666
50,000
200
180
160
140
1,000
Mbps
Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
4
3
3
3
20,000
10,000
6,666
5,000
20
18
16
14
10 Gbps
Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
2
1
1
1
2,000
1,000
666
500
2
1
1
1
Normally, the path cost of a port operating in full-duplex mode is slightly less than that of
the port operating in half-duplex mode.
When calculating the path cost of an aggregated link, the 802.1D-1998 standard does
not take the number of the ports on the aggregated link into account, whereas the
802.1T standard does. The following formula is used to calculate the path cost of an
aggregated link:
Path cost = 200,000,000/ link transmission speed,
