H3C Technologies H3C S3100 Series Switches - Manual (Page 203)

Operation Manual – MSTP
H3C S3100-52P Ethernet Switch
Chapter 1 MSTP Configuration
1-28
1.3.7 Configuring the Path Cost for a Port
The path cost parameter reflects the rate of the link connected to the port. For a port on
an MSTP-enabled switch, the path cost may be different in different spanning tree
instances. You can enable flows of different VLANs to travel along different physical
links by configuring appropriate path costs on ports, so that VLAN-based load
balancing can be implemented.
Path cost of a port can be determined by the switch or through manual configuration.
I. Standards for calculating path costs of ports
Currently, a switch can calculate the path costs of ports based on one of the following
standards:
z dot1d-1998 : Adopts the IEEE 802.1D-1998 standard to calculate the default path
costs of ports.
z dot1t : Adopts the IEEE 802.1t standard to calculate the default path costs of ports.
z legacy : Adopts the proprietary standard to calculate the default path costs of
ports.
Table 1-22 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 IEEE
802.1t standard is used to
calculate the default path
costs of ports.
Table 1-23 Transmission speeds and the corresponding path costs
Transmissio
n speed
Operation
mode
(half-/full-dup
lex)
802.1D-1998 IEEE 802.1t
Proprietary
standard
0 — 65,535 200,000,000 200,000
10 Mbps
Half-duplex/F
ull-duplex
Aggregated
link 2 ports
Aggregated
link 3 ports
Aggregated
link 4 ports
100
95
95
95 200,000
1,000,000
666,666
500,000 2,000
1,800
1,600
1,400