3com 5500-ei pwr Instruccion De Instalación

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1-30 
Configuring the Timeout Time Factor 
Refer to 
Configuring the Maximum Transmitting Rate on the Current Port 
Refer to 
Configuring a Port as an Edge Port 
Refer to 
Configuring the Path Cost for a Port 
The path cost parameter reflects the rate of the link connected to the port. For a port on an 
MSTP-enabled switch, the path cost may be different in different MSTIs. You can enable flows of 
different VLANs to travel along different physical links by configuring appropriate path costs on ports, so 
that VLAN-based load balancing can be implemented. 
Path cost of a port can be determined by the switch or through manual configuration. 
Standards for calculating path costs of ports 
Currently, a switch can calculate the path costs of ports based on one of the following standards: 
z
 
dot1d-1998
: Adopts the IEEE 802.1D-1998 standard to calculate the default path costs of ports. 
z
 
dot1t
: Adopts the IEEE 802.1t standard to calculate the default path costs of ports. 
z
 
legacy
: Adopts the proprietary standard to calculate the default path costs of ports. 
Follow these steps to specify the standard for calculating path costs: 
To do... 
Use the command... 
Remarks 
Enter system view 
system-view 
— 
Specify the standard for 
calculating the default path 
costs of the links connected to 
the ports of the switch 
stp pathcost-standard
 
dot1d-1998 | dot1t | legacy }
Optional 
By default, the legacy standard 
is used to calculate the default 
path costs of ports. 
 
Table 1-7 
Transmission rates vs. path costs 
Rate 
Operation mode 
(half-/full-duplex) 
802.1D-1998 
IEEE 802.1t 
Latency 
standard  
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 
2,000,000 
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