3Com Switch 7754, Configuration Manual

Page: 260 / 940

260 C
HAPTER
30: MSTP C
ONFIGURATION
MST Region
Configuration
Refer to “MST Region Configuration” on page 247.
MSTP Operation Mode
Configuration
Refer to “MSTP Operation Mode Configuration” on page 250.
Timeout Time Factor
Configuration
Refer to “Timeout Time Factor Configuration” on page 254.
Maximum Transmitting
Speed Configuration
Refer to “Maximum Transmitting Speed Configuration” on page 254.
Edge Port Configuration Refer to “Edge Port Configuration” on page 255.
Path Cost Configuration The path cost parameters reflects the link rates on ports. For a port on an
MSTP-enabled switch, the path cost may differ with spanning tree instance. You
can enable flows of different VLANs to travel along different physical links by
configuring appropriate path costs on ports, so that load balancing can be
achieved by VLANs.
Path cost can be determined by switch or through manual configuration.
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 standard defined by private to calculate the default path
costs of ports.
Table 190 Specify the standard for calculating path costs
Operation Command Description
Enter system view system-view -
Specify the standard to be
used to calculate the default
path costs of the links
connected to the ports of the
switch stp
pathcost-standard
{ dot
1d-1998 | dot1t |
legacy }
Optional
By default, the legacy standard is
used to calculate the default path
costs.
Table 191 Transmission speeds and the corresponding path costs
Transmis
sion
speed
Operation mode
(half-/full-duplex) 802.1D-1998 IEEE
802.1t
Proprietary
standard
0 - 65,535 200,000,000 200,000