3Com 5500-EI PWR, Reference Manual

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stp timer forward-delay
Syntax
stp timer forward-delay centi-seconds
undo stp timer forward-delay
View
System view
Parameters
centi-seconds : Forward delay in centiseconds to be set. This argument ranges from 400 to 3,000.
Description
Use the stp timer forward-delay command to set the forward delay of the switch.
Use the undo stp timer forward-delay command to restore the forward delay to the default value.
By default, the forward delay of the switch is 1,500 centiseconds.
To prevent the occurrence of temporary loops, when a port changes its state from discarding to
forwarding, it undergoes an intermediate state and waits for a specific period to synchronize with the
state transition of the remote switches. This state transition period is determined by the forward delay
configured on the root bridge.
The forward delay setting configured on a root bridge applies to all non-root bridges.
As for the configuration of the three time-related parameters (namely, the hello time, forward delay, and
max age parameters), the following formulas must be met to prevent frequent network jitter.
2 x (forward delay – 1 second) >= max age
Max age >= 2 x (hello time + 1 second)
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 automatically calculated by MSTP.
Related commands: stp timer hello , stp timer max-age , stp bridge-diameter .
Examples
# Set the forward delay to 2,000 centiseconds.
<Sysname> system-view
System View: return to User View with Ctrl+Z.
[Sysname] stp timer forward-delay 2000
stp timer hello
Syntax
stp timer hello centi-seconds
undo stp timer hello
View
System view