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Table 13 Mappings between the link speed and the path cost
Link speed
Port type
Path cost
IEEE 802.1d-1998
IEEE 802.1t
Private
standard
0 N/A
65535 200,000,000
200,000
10 Mbps
Single port
100
2,000,000 2000
Aggregate interface
containing 2 Selected
ports
1,000,000 1800
Aggregate interface
containing 3 Selected
ports
666,666 1600
Aggregate interface
containing 4 Selected
ports
500,000 1400
100 Mbps
Single port
19
200,000 200
Aggregate interface
containing 2 Selected
ports
100,000 180
Aggregate interface
containing 3 Selected
ports
66,666 160
Aggregate interface
containing 4 Selected
ports
50,000 140
1000 Mbps
Single port
4
20,000 20
Aggregate interface
containing 2 Selected
ports
10,000 18
Aggregate interface
containing 3 Selected
ports
6666 16
Aggregate interface
containing 4 Selected
ports
5000 14
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 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-1998 does not. The