Configuration Example - HP A3100-8 v2 SI Configuration Manual

Link speed
NOTE:
When calculating path cost for an aggregate interface, IEEE 802.1d-1998 does not take into account the
number of selected ports in its aggregation group as IEEE 802.1t does. 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
Follow these steps to configure the path cost of ports:
To do...
Enter system view
Enter interface
view or port
group view
Configure the path cost of the ports
CAUTION:
When the path cost of a port changes, MSTP re-calculates the role of the port and initiates a state
transition.

Configuration example

# Specify that the device uses IEEE 802.1d- 1 998 to calculate the default path costs of its ports.
<Sysname> system-view
[Sysname] stp pathcost-standard dot1d-1998
# Set the path cost of Ethernet 1/0/3 on MSTI 2 to 200.
<Sysname> system-view
[Sysname] interface ethernet 1/0/3
[Sysname-Ethernet1/0/3] stp instance 2 cost 200
Port type
Aggregate interface
containing 3 selected ports
Aggregate interface
containing 4 selected ports
Enter Ethernet interface
view or Layer 2 aggregate
interface view
Enter port group view
Path cost
IEEE
IEEE 802.1t
802.1d-1998
666
500
Use the command...
system-view
interface interface-type
interface-number
port-group manual
port-group-name
stp [ instance instance-id ]
cost cost
69
Private standard
1
1
Remarks
—
Required
Use either command.
Required
By default, MSTP
automatically calculates the
path cost of each port.