3com 8807 Reference Guide

C

HAPTER

 13: MSTP C

ONFIGURATION

 C

OMMANDS

stp [ instance instance-id ] root primary [ bridge-diameter bridgenum [ 
hello-time centi-senconds ] ]

undo stp [ instance instance-id ] root

System view

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.

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.

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