Set Forward Delay Of A Specified Bridge; Set Hello Time Of The Specified Bridge; Set Max Age Of The Specified Bridge - 3Com 5500-SI Configuration Manual

550 C 26: RSTP C
HAPTER
Set Forward Delay of a
Specified Bridge
Set Hello Time of the
Specified Bridge
Set Max Age of the
Specified Bridge
ONFIGURATION
By default, a Switch is neither the primary root nor the secondary root of the
spanning tree.
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 frames right away, this can cause an occasional loop. 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.
Table 602 Set Forward Delay of a Specified Bridge
Operation

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, restoring the network connection may take a
long time. It is recommended to use the default setting.
By default, the bridge Forward Delay is 15 seconds.
A bridge transmits hello packet regularly to the adjacent bridges to check if there is
link failure.
You can use the following command to set the Hello Time of a specified bridge.
Perform the following configurations in System View.
Table 603 Set Hello Time of the Specified Bridge
Operation

Set Hello Time of the specified bridge

Restore the default Hello Time of the specified bridge undo stp timer hello
An appropriate Hello Time can ensure that the bridge can detect certain link failures
in the network in a timely manner. It is strongly recommended that default value of 2
seconds is retained.
By default, the Hello Time of the bridge is 2 seconds.
Max Age is a parameter to judge whether the configuration BPDU is "timeout". Users
can configure it according to the actual network situation.
You can use the following command to set Max Age of a specified bridge.
Perform the following configuration in System View.
Command
stp timer forward-delay centiseconds
undo stp timer forward-delay
Command
stp timer hello centiseconds