H3C S3100 8C SI Operation Manual page 279

Operation Manual – MSTP
H3C S3100 Series Ethernet Switches
Table 1-28 Specify the standard for calculating path costs
Enter system view
Specify the standard for
calculating the default
path costs of the links
connected to the ports of
the switch
Table 1-29 Transmission speeds and the corresponding path costs
Transmiss
ion speed
0
10 Mbps
100 Mbps
1,000
Mbps
10 Gbps
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:
Operation
system-view
stp pathcost-standard
{ dot1d-1998 | dot1t |
legacy }
Operation mode
(half-/full-duplex)
—
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
Path cost = 200,000,000/ link transmission speed,
Command
802.1D-1998
65,535
100
95
95
95
19
15
15
15
4
3
3
3
2
1
1
1
1-38
Chapter 1 MSTP Configuration
Description
—
Optional
By default, the legacy
standard is used to
calculate the default path
costs of ports.
Proprietary
IEEE 802.1t
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