H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 84)

74
Link speed Port type
Path cost
IEEE
802.1d-1998
IEEE 802.1t Private standard
Aggregate interface
containing 3 selected ports
666 1
Aggregate interface
containing 4 selected ports
500 1
NOTE:
When calculating path cost for an aggregate interface, IEEE 802.1t takes into account the number of
selected ports in its aggregation group, but IEEE 802.1d-1998 does not. The calculation formula of IEEE
802.1t is: Path Cost = 200,000,000/link speed (in 100 kbps), where link speed is the sum of the link
speed values of the selected ports in the aggregation group.
Configuring path costs of ports
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter interface view or port
group view.
• Enter Ethernet interface view:
interface interface-type
interface-number
• Enter port group view:
port-group manual
port-group-name
Use either command.
3. Configure the path cost of the
ports.
• In STP/RSTP mode:
stp cost cost
• In MSTP mode:
stp [ instance instance-id ] cost
cost
Use either command.
By default, the system
automatically calculates the
path cost of each port.
NOTE:
When the path cost of a port changes, the system re-calculates the role of the port and initiates a state
transition.
Configuration example
# In MSTP mode, specify the device to calculate the default path costs of its ports by using IEEE
802.1d-1998, and set the path cost of GigabitEthernet 1/0/3 to 200 on MSTI 2.
system-view
[Sysname] stp pathcost-standard dot1d-1998
[Sysname] interface gigabitethernet 1/0/3
[Sysname-GigabitEthernet1/0/3] stp instance 2 cost 200