H3C Technologies H3C WX5500E Series Access Controllers - Manual (Page 91)

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Link speed Port type
Path cost
IEEE
802.1d-1998
IEEE 802.1t Private standard
10 Gbps
Single port
2
2000 2
Aggregate interface
containing 2 Selected ports
1000 1
Aggregate interface
containing 3 Selected ports
666 1
Aggregate interface
containing 4 Selected ports
500 1
Configuration guidelines
When you specify a standard for the device to use when it calculates the default path cost, follow these
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-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.
• When the link speed of a single port exceeds 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. This affects the reasonableness of forwarding path selection. To solve this
problem, use dot1t as the standard for default path cost calculation, or manually set the path cost
for a port. For how to set the path costs of ports, see " Configuring path costs of ports ."
Configuration procedure
To specify a standard for the device to use when it calculates the default path cost:
Step Command Remarks
1. Enter system view. system-view N/A
2. Specify a standard for the
device to use when it
calculates the default path
costs of its ports.
stp pathcost-standard
{ dot1d-1998 | dot1t | legacy } Optional.
The default setting is legacy.
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 Command Remarks
1. Enter system view. system-view N/A