Stp Instance Root Primary - Huawei Quidway S8500 Series Command Manual

Command Manual – STP
Quidway S8500 Series Routing Switches

1.1.16 stp instance root primary

Syntax
stp [ instance instance-id ] root primary [ bridge-diameter bridgenum [ hello-time
centi-senconds ] ]
undo stp [ instance instance-id ] root
View
System view
Parameter
instance-id: Specifies the spanning tree instance ID, ranging from 0 to 48. Specify it as
0 to configure the root bridge of CIST.
root primary: Configures the current switch as the primary root of the specified MSTI.
bridge-diameter bridgenum: Specifies the network diameter of the spanning tree,
ranging from 2 to 7.
hello-time centi-senconds: Specifies the Hello Time of the spanning tree, which is in
the range from 100 to 1000 and measured in centiseconds.
Description
Use the stp root primary command to configure the current switch as the primary root
of the specified MSTI.
Use the undo stp root command to cancel the current switch for the primary root of the
designated MSTI.
If you execute these commands without using the instance instance-id option, your
configuration takes effect only on the CIST instance.
When you set the instance-id parameter to 0, its following parameter setting takes
effect.
By default, the switch does not server as a root bridge.
You can specify one root bridge for each MSTI regardless of the switch priority. When
setting a root bridge, you can use this command to specify the switching network
diameter and determine the three time parameters (Hello time, Forward Delay and Max
Age). Because the switch calculates inaccurate Hello time value, you can specify the
switching network diameter and the Hello Time for the root bridge, and thus determine
other two parameter values for the root bridge. In general, you are recommended to
determine the other two time parameter values by setting the network diameter.
Huawei Technologies Proprietary
1-17
Chapter 1 MSTP Configuration Commands