Set Forward Delay Of A Specified Bridge - Huawei Quidway S3000 Series Operation Manual

Operation Manual - STP
Quidway S3000 Series Ethernet Switches
Note:
To configure a switch as the root of the spanning tree instance, you can specify its priority as 0 or simply
set it as the root, using the command.
It is not necessary to specify two or more roots for an STI. In other words, please do not specify the root for
an STI on two or more switches.
You can configure more than one secondary root for a spanning tree through specifying the secondary STI
root on two or more switches.
Generally, you are recommended to designate one primary root and more than one secondary roots for a
spanning tree.
By default, a switch is neither the primary root nor the secondary root of the spanning
tree.

1.2.6 Set Forward Delay of a Specified Bridge

Link failure will cause recalculation of the spanning tree and change its structure.
However, the newly calculated configuration BPDU cannot be propagated throughout
the network immediately. If the newly selected root port and designated port begin to
forward data frame right away, occasional loop can be caused. Accordingly, the
protocol adopts a state transition mechanism, that is, the root port and the designated
port must undergo a transition state for a period of Forward Delay before they transition
to the forwarding state and resume data frame forwarding. This delay ensures that the
new configuration BPDU has been propagated throughout the network before the data
frame forwarding is resumed.
You can use the following command to set the Forward Delay for a specified bridge.
Perform the following configurations in system view.
Table1-6 Set forward delay of a specified bridge
Set Forward Delay of a specified bridge
Restore the default Forward Delay of specified bridge
Forward Delay of the bridge is related to the diameter of the switching network. As a
rule , the larger the network diameter , the longer the Forward Delay. Note that if the
Forward Delay is configured too short, occasional path redundancy may occur. If the
Forward Delay is configured too long, the restoring of network connection may take a
long time. It is recommended to use the default setting.
By default, the bridge Forward Delay is 15 seconds.
Operation
1-11
Chapter 1 RSTP Configuration
Command
stp timer forward-delay centiseconds
undo stp timer forward-delay