3com S7906E Manuel De Montage

 

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Enable output of port state transition 
information 

{ all | 

instance instance-id 

} 

Required 
This function is enabled by 
default. 

 

You must enable MSTP for the device before any other MSTP-related configurations can take effect. 

Make this configuration on the root bridge and on the leaf nodes separately.  

Follow these steps to enable the MSTP feature: 

Enter system view 

 

— 

Enable the MSTP feature globally 

 

Required 
MSTP is globally disabled by 
default. 

Enter Ethernet 
interface view, or 
Layer 2 aggregate 
interface view 

interface interface-type 
interface-number 

Enter 
interface view 
or port group 
view 

Enter port group 
view 

port-group manual 
port-group-name 

Required 
Use either command. 

Enable the MSTP feature for the 
ports 

 enable 

Optional 
By default, MSTP is enabled 
for all ports after it is enabled 
for the device globally. 

 

To control MSTP flexibly, you can use the undo stp enable command to disable the MSTP feature for 
certain ports so that they will not take part in spanning tree calculation and thus to save the CPU 
resources of the device. 

 

Performing mCheck 

MSTP has three working modes: STP compatible mode, RSTP mode, and MSTP mode. 

If a port on a device running MSTP (or RSTP) connects to a device running STP, this port will 
automatically migrate to the STP-compatible mode. However, it will not be able to migrate automatically 
back to the MSTP (or RSTP) mode, but will remain working in the STP-compatible mode under the 
following circumstances: 

z

 

The device running STP is shut down or removed. 

z

 

The device running STP migrates to the MSTP (or RSTP) mode.