Configuring Path Costs Of Ports - HP 6125G Configuration Manual

Link speed
10 Gbps
Configuration restrictions and guidelines
When it calculates 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- 1 998 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.
• When multiple ports operate at a rate higher than 10 Gbps and the standard for default path cost
calculation is dot1d-1998 or legacy, the path cost of a single port or an aggregate interface takes
the smallest value. As a result, the forwarding path selected might not be optimal. To solve this
problem, use dot1t as the standard for default path cost calculation, or manually set the path cost
for a port
Configuration procedure
To specify a standard for the device to use when it calculates the default path cost:
Step
1. Enter system view.
2. Specify a standard for the
device to use when it
calculates the default path
costs of its ports.

Configuring path costs of ports

When the path cost of a port changes, the system re-calculates the role of the port and initiates a state
transition.
To configure the path cost of ports:
Step
1. Enter system view.
Port type
Aggregate interface
containing 3 Selected ports
Aggregate interface
containing 4 Selected ports
Single port
Aggregate interface
containing 2 Selected ports
Aggregate interface
containing 3 Selected ports
Aggregate interface
containing 4 Selected ports
(Configuring path costs of
Command
system-view
stp pathcost-standard
{ dot1d-1998 | dot1t | legacy }
Command
system-view
Path cost
IEEE 802.1d-1998
2
ports).
74
IEEE 802.1t Private standard
6666 16
5000 14
2000 2
1000 1
666 1
500 1
Remarks
N/A
Optional.
legacy by default.
Remarks
N/A