Configuring path costs of ports – H3C Technologies H3C WX6000 Series Access Controllers User Manual

Page 187

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20-29

Configuring Path Costs of Ports

Path cost is a parameter related to the rate of port-connected links. On an MSTP-compliant device,
ports can have different priorities in different MST instances. Setting an appropriate path cost allows
VLAN traffic flows to be forwarded along different physical links, thus to enable per-VLAN load
balancing.

The device can automatically calculate the default path cost; alternatively, you can also configure the
path cost for ports.

Specifying a standard that the device uses when calculating the default path cost

You can specify a standard for the device to use in automatic calculation for the default path cost. The
device supports the following standards:

z

dot1d-1998

: The device calculates the default path cost for ports based on IEEE 802.1d-1998.

z

dot1t

: The device calculates the default path cost for ports based on IEEE 802.1t.

z

legacy

: The device calculates the default path cost for ports based on a private standard.

Follow these steps to specify a standard for the device to use when calculating the default path cost:

To do...

Use the command...

Remarks

Enter system view

system-view

Specify a standard for the device to use
when calculating the default path cost of
the link connected with the device

stp pathcost-standard

{ dot1d-1998 |

dot1t

| legacy }

Optional

legacy

by default

Table 20-7

Link speed vs. path cost

Link speed

Duplex state

802.1d-1998

802.1t

Private

standard

0 —

65535

200,000,000

200,000

10 Mbps

Single Port
Aggregated Link 2 Ports
Aggregated Link 3 Ports
Aggregated Link 4 Ports

100
100
100
100

2,000,000
1,000,000
666,666
500,000

2,000
1,800
1,600
1,400

100 Mbps

Single Port
Aggregated Link 2 Ports
Aggregated Link 3 Ports
Aggregated Link 4 Ports

19
19
19
19

200,000
100,000
66,666
50,000

200
180
160
140

1000 Mbps

Single Port
Aggregated Link 2 Ports
Aggregated Link 3 Ports
Aggregated Link 4 Ports

4
4
4
4

20,000
10,000
6,666
5,000

20
18
16
14

10 Gbps

Single Port
Aggregated Link 2 Ports
Aggregated Link 3 Ports
Aggregated Link 4 Ports

2
2
2
2

2,000
1,000
666
500

2
1
1
1

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