3Com 4200G 24-Port - Configuring the Timeout Time Factor; Configuring the Maximum Transmitting Rate on the Current Port

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You are recommended to specify the network diameter of the switched network and the hello time by
using the stp root primary or stp root secondary command. After that, the three proper time-related
parameters are determined automatically.
Configuration example
# Configure the forward delay parameter to be 1,600 centiseconds, the hello time parameter to be 300
centiseconds, and the max age parameter to be 2,100 centiseconds (assuming that the current switch
operates as the CIST root bridge).
<Sysname> system-view
[Sysname] stp timer forward-delay 1600
[Sysname] stp timer hello 300
[Sysname] stp timer max-age 2100
Configuring the Timeout Time Factor
When the network topology is stable, a non-root-bridge switch regularly forwards BPDUs received from
the root bridge to its neighboring devices at the interval specified by the hello time parameter to check
for link failures. Normally, a switch regards its upstream switch faulty if the former does not receive any
BPDU from the latter in a period three times of the hello time and then initiates the spanning tree
recalculation process.
Spanning trees may be recalculated even in a steady network if an upstream switch continues to be
busy. You can configure the timeout time factor to a larger number to avoid such cases. Normally, the
timeout time can be four or more times of the hello time. For a steady network, the timeout time can be
five to seven times of the hello time.
Configuration procedure
Follow these steps to configure the timeout time factor:
To do... Use the command... Remarks
Enter system view
system-view
—
Configure the timeout time
factor for the switch
stp timer-factor number
Required
The timeout time factor defaults
to 3.
For a steady network, the timeout time can be five to seven times of the hello time.
Configuration example
# Configure the timeout time factor to be 6.
<Sysname> system-view
[Sysname] stp timer-factor 6
Configuring the Maximum Transmitting Rate on the Current Port
The maximum transmitting rate of a port specifies the maximum number of configuration BPDUs a port
can transmit in a period specified by the hello time parameter. It depends on the physical state of the
port and network structure. You can configure this parameter according to the network.