H3C S5120-SI Series Command Reference Manual page 205

Description
Use the stp timer max-age command to set the max age timer of the device.
Use the undo stp timer max-age command to restore the system default.
By default, the max age is set to 2,000 centiseconds.
MSTP can detect link failures and automatically restore the forwarding state of the redundant link. In the
CIST, the device determines whether a configuration BPDU received on a port has expired based on
the max age timer. If a port receives a configuration BPDU that has expired, that MSTI needs to be
re-computed.
The max age timer is not meaningful for MSTIs. If the current device is the root bridge of the CIST, it
determines whether a configuration BPDU has expired based on the configured max age timer; if the
current device is not the root bridge of the CIST, it uses the max age timer set on the CIST root bridge.
The settings of the hello time, forward delay and max age timers must meet the following formulae, thus
avoiding frequent network changes:
2 × (forward delay – 1 second) ƒ max age
Max age ƒ 2 × (hello time + 1 second)
We recommend that you specify the network diameter using the stp root primary command and let
MSTP automatically calculate an optimal setting of these three timers.
Related commands: stp timer forward-delay, stp timer hello, stp bridge-diameter.
Examples
# Set the max age timer of the device to 1,000 centiseconds.
<Sysname> system-view
[Sysname] stp timer max-age 1000
stp timer-factor
Syntax
stp timer-factor factor
undo stp timer-factor
View
System view
Default Level
2: System level
Parameters
factor: Timeout factor, in the range of 1 to 20.
Description
Use the stp timer-factor command to set the timeout factor, which decides the timeout time. Timeout
time = timeout factor × 3 × hello time.
Use the undo stp timer-factor command to restore the default.
By default, the timeout factor is 3.
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