3com WX3000 Manual De Usuario

 

1-18 

Enter system view 

— 

Specify the current device as the 
root bridge of a spanning tree 

[ instance instance-id ] root primary 

[ bridge-diameter bridgenumber [ hello-time 
centi-seconds 

] ] 

Required 

 

Follow these steps to specify the current device as the secondary root bridge of a spanning tree: 

Enter system view 

— 

Specify the current device as 
the secondary root bridge of a 
specified spanning tree 

[ instance instance-id ] root secondary 

[ bridge-diameter bridgenumber [ hello-time 
centi-seconds

 ] ] 

Required 

 

Using the stp root primary/stp root secondary command, you can specify the current device as the 
root bridge or the secondary root bridge of the spanning tree instance identified by the instance-id 
argument. If the value of the instance-id argument is set to 0, the stp root primary/stp root secondary 
command specify the current device as the root bridge or the secondary root bridge of the CIST. 

A device can play different roles in different spanning tree instances. That is, it can be the root bridges in 
a spanning tree instance and be a secondary root bridge in another spanning tree instance at the same 
time. But in the same spanning tree instance, a device cannot be the root bridge and the secondary root 
bridge simultaneously. 

When the root bridge fails or is turned off, the secondary root bridge becomes the root bridge if no new 
root bridge is configured. If you configure multiple secondary root bridges for a spanning tree instance, 
the one with the smallest MAC address replaces the root bridge when the latter fails. 

You can specify the network diameter and the hello time parameters while configuring a root 
bridge/secondary root bridge. Refer to 

 and 

 for information about the network diameter parameter 

and the hello time parameter.