3com S7906E Manuel De Montage

 

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

Enter system view 

 

— 

Configure the current device as 
a secondary root bridge of a 
specific spanning tree 

[ instance instance-id ] 

 

Required 
By default, a device does not 
function as a secondary root 
bridge. 

 

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After specifying the current device as the root bridge or a secondary root bridge, you cannot 
change the priority of the device. 

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Alternatively, you can also configure the current device as the root bridge by setting the priority of 
the device to 0. For the device priority configuration, refer to 

. 

 

Being mutually compatible, MSTP and RSTP can recognize each other’s protocol packets. However, 
STP is unable to recognize MSTP packets. For hybrid networking with legacy STP devices and for full 
interoperability with RSTP-enabled devices, MSTP supports three work modes: STP-compatible mode, 
RSTP mode, and MSTP mode. 

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In STP-compatible mode, all ports of the device send out STP BPDUs, 

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In RSTP mode, all ports of the device send out RSTP BPDUs. If the device detects that it is 
connected with a legacy STP device, the port connecting with the legacy STP device will 
automatically migrate to STP-compatible mode. 

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In MSTP mode, all ports of the device send out MSTP BPDUs. If the device detects that it is 
connected with a legacy STP device, the port connecting with the legacy STP device will 
automatically migrate to STP-compatible mode. 

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

Follow these steps to configure the MSTP work mode: 

Enter system view 

 

— 

Configure the work mode of 
MSTP 

 { stp | rstp | mstp } 

Required 
MSTP mode by default 

 

Device priorities participate in spanning tree calculation. The priority of a device determines whether it 
can be elected as the root bridge of a spanning tree. A lower value indicates a higher priority. By setting