Stp Timer Hello - H3C S3100-52P Command Manual

Command Manual – MSTP
H3C S3100-52P Ethernet Switches
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 command: stp timer hello, stp timer max-age, and stp bridge-diameter.
Example
# Set the forward delay of the switch to 2,000 centiseconds.
<H3C> system-view
System View: return to User View with Ctrl+Z.
[H3C] stp timer forward-delay 2000

1.1.43 stp timer hello

Syntax
stp timer hello centi-seconds
undo stp timer hello
View
System view
Parameter
centi-seconds: Hello time in centiseconds to be set. This argument is an integer
ranging from 100 to 1,000 and defaults to 200.
Description
Use the stp timer hello command to set the hello time of the switch.
Use the undo stp timer hello command to restore the hello time of the switch to the
default value.
A root bridge regularly sends out configuration BPDUs to maintain the stability of
existing spanning trees. If the switch does not receive BPDU packets in a specified
period, spanning trees will be recalculated because BPDU packets time out. When a
switch becomes a root bridge, it regularly sends BPDUs at the interval specified by the
hello time you have configured on it. The other none-root-bridge switches adopt the
interval specified by the hello time.
Chapter 1 MSTP Configuration Commands
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