Bridge Stp Timer Hello - 3Com 3C13618 Command Reference Manual

3Com Router Command Reference Guide — V1.00
the network immediately. If the newly selected root interface and the designated
interface begin to forward data frames right away, temporary loop can be caused.
Therefore, the protocol adopts a state transition mechanism, that is, the root interface
and the designated interface will undergo a transitional state for an interval of
Forwarding Delay before they enter the forwarding state to resume data forwarding.
This delay ensures that the new BPDUs have been propagated throughout the network
before the data forwarding is resumed. In fact, the Forward Delay timer is used to
control the interval that the system will wait to enter the forwarding state.
It should be noted when configuring the Forward Delay timer of bridge:
In the spanning tree, all the bridges use the time value of Hello Time timer of the
root bridge, and their own configurations take no effect.
If the Forward Delay is configured too short, there is the possibility of redistributing
temporary redundant paths. If the Forward Delay is configured too long, however,
restoring of network connection may take a long time because the STP cannot
converge to a stable state for a long period. It is recommended that users use the
default value.
Example
# Configure the time value of the Forward Delay timer of bridge to 50 seconds.
[3Com]bridge stp timer forward-delay 50

8.1.14 bridge stp timer hello

Syntax
bridge stp timer hello seconds
undo bridge stp timer hello
View
System view
Parameter
seconds: Value of the Hello Time timer of bridge, in the range of 1 to 10 seconds. By
default, the value of Hello Time timer is 2 seconds.
Description
Using the bridge stp timer hello command, you can configure the time value of the
Hello Time timer of bridge. Using the undo bridge stp timer hello command, you can
restore the default value of the Hello Time timer.
Hello Time timer is used to control the interval of BPDUs sending. Whenever the
Spanning Tree Protocol (STP) is enabled, the interface enables the Hello Time timer
and sends BPDUs to the sub-interface regularly. Appropriate Hello Time ensures that
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