3Com 7750 Series, Справочник по командам

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3Com Switch 7750 Series
Command Reference Guide – MSTP Chapter 1 MSTP Configuration Commands
1-33
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System view
Parameter
dot1d-1998 : Uses the IEEE 802.1D-1998 standard to calculate the default path costs
of ports.
dot1t : Uses the IEEE 802.1t standard to calculate the default path costs of ports.
legacy : Uses the proprietary standard to calculate the default path costs of ports.
Description
Use the stp pathcost-standard command to set the standard to be used to calculate
the default path costs of the links connected to the switch.
Use the undo stp pathcost-standard command to specify to use the default standard.
By default, a switch uses the IEEE 802.1t standard to calculate the default path costs of
ports.
Table 1-4 Transmission speeds and the corresponding path costs
Transm
ission
speed
Operation mode
(half-/full-duplex)
802.1D-1998 IEEE 802.1t
Standard
defined by
Private
0 - 65,535 200,000,000 200,000
10
Mbps
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
100
95
95
95
200,000
1,000,000
666,666
500,000
2,000
1,800
1,600
1,400
100
Mbps
Half-duplex/Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
19
15
15
15
200,000
100,000
66,666
50,000
200
180
160
140
1,000
Mbps
Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
4
3
3
3
200,000
10,000
6,666
5,000
20
18
16
14
10
Gbps
Full-duplex
Aggregated link 2 ports
Aggregated link 3 ports
Aggregated link 4 ports
2
1
1
1
200,000
1,000
666
500
2
1
1
1