3Com 4210 PWR Configuration Manual page 171

Standards for calculating path costs of ports
Currently, a switch can calculate the path costs of ports based on one of the
following standards:
dot1d-1998: Adopts the IEEE 802.1D-1998 standard to calculate the default
■
path costs of ports.
dot1t: Adopts the IEEE 802.1t standard to calculate the default path costs of
■
ports.
legacy: Adopts the proprietary standard to calculate the default path costs of
■
ports.
Table 122 Specify the standard for calculating path costs
Operation
Enter system view
Specify the standard for
calculating the default path
costs of the links connected to
the ports of the switch
Table 123 Transmission speeds and the corresponding path costs
Transmission Operation mode
speed (half-/full-duplex)
0 -
10 Mbps Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
100 Mbps Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
1,000 Mbps Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
10 Gbps Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
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,
Command
system-view
stp pathcost-standard {
dot1d-1998 | dot1t | legacy}
802.1D-1998
65,535
100
95
95
95
19
15
15
15
4
3
3
3
2
1
1
1
Configuring Leaf Nodes
Description
-
Optional
By default, the legace
standard is used to calculate
the default path costs of
ports.
Proprietary
IEEE 802.1t standard
200,000,000 200,000
200,000 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
200,000 20
10,000 18
6,666 16
5,000 14
200,000 2
1,000 1
666 1
500 1
169