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Table 7 Mappings between the link speed and the path cost
Link speed
0
10 Mbps
100 Mbps
1000 Mbps
10 Gbps
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
To configure the path cost of ports:
Port type
N/A
Single Port
Aggregate interface
containing 2 selected ports
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
Single Port
Aggregate interface
containing 2 selected ports
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
Path cost
IEEE
IEEE 802.1t
802.1d-1998
65535
200,000,000
2,000,000
1,000,000
100
666,666
500,000
200,000
100,000
19
66,666
50,000
20,000
10,000
4
6666
5000
2000
1000
2
666
500
49
Private standard
200,000
2,000
1,800
1,600
1,400
200
180
160
140
20
18
16
14
2
1
1
1
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