Stp Timer-Factor - 3Com 8807 Command Reference Manual

MSTP Configuration Commands 207
When you configure Hello time, Forward Delay and Max Age, remember to
guarantee the following equations:
2 x (Forward Delay -1.0 second) >= Max Age
Max Age >= 2 x (Hello Time + 1.0 second)
Only if the earlier-mentioned formulas are equal can the MSTP normally operate
on the entire network. Otherwise, the network may flap frequently. You are
recommended to use the stp bridge-diameter command to specify the diameter
of the switching network, so that MSTP can automatically calculate and give the
moderate values for the time parameters.
Related command: stp timer forward-delay, stp timer hello, stp
bridge-diameter.
Example
# Set Max Age of the device to 1000 centiseconds.
<SW8800>system-view
System View: return to User View with Ctrl+Z.
[SW8800] stp timer max-age 1000

stp timer-factor

Syntax
stp timer-factor number
undo stp timer-factor
View
System view
Parameter
number: Specifies the multiple of hello time, in the range of 1 to 10. The default
value is 3.
Description
Use the stp timer-factor command to configure the multiple of hello time for the
switch.
Use the undo stp timer-factor command to restore the default multiple value.
The Ethernet switch transmits STP packets every hello time. Generally, if the switch
does not receive the STP packets from the upstream switch for three times of hello
time, the switch will decide the upstream switch is dead and will recalculate the
topology of the network. Then in steady network, the recalculation may be caused
when the upstream is busy. In this case, users can redefine the timeout interval to
a longer time (four times the hello time or larger) by define the multiple of hello
time. It is recommended to set 5, 6 or 7 as the value of multiple in the steady
network.
Example
# Set the multiple value of hello time to 7.