The MSTP Configuration of stp priority

Function Description

The multiple spanning tree protocol (MSTP) applies to the redundant network. MSTP is an improvement of STP and RSTP. MSTP prevents the proliferation and infinite cycling of the packets in the loop network. In addition, MSTP provides multiple redundant paths for VLAN data transmission to achieve the load-sharing purpose. The MA5600T/MA5683T/MA5608T supports MSTP, which is compatible with the STP and RSTP. It supports MSTP loop network that helps meet various networking requirements.

Function

The stp priority command is used to set the priority of a device in the specified spanning tree instance. The device priority decides that whether the device can be selected as the root bridge of the spanning tree. When you need to set the device priority to realize the goal of specifying a device as the root bridge of the spanning tree, run this command. After the device priority is set, the set value serves as the criterion for deciding whether to select the device as the root bridge of the spanning tree.
The undo stp priority command is used to restore the default priority of a device in the specified spanning tree instance. After the default priority of a device is restored, the priority of the device in the specified spanning tree instance is 32768.

NOTE:

In the process of selecting the root of the spanning tree, among the devices with same priority, the device with the smallest MAC address will be selected as the tree root.

Format

stp [ instance instance-id ] priority priority
undo stp [ instance instance-id ] priority

Parameters

Parameter	Description	Value
instance instance-id	Indicates the spanning tree instance ID. The value 0 indicates the Common And Internal Spanning Tree (CIST) instance and other value indicate the Multiple Spanning Tree Instance (MSTI).	Numeral type. Range: 0-16.
priority priority	Indicates the device priority, in steps of 4096. The smaller the set value is, the higher device priority is.	Numeral type. Range: 0-61440. Default: 32768.

Modes

Global config mode

Level

Operator level

Usage Guidelines

• The device with smaller priority value is more possible to be selected as the root bridge of the spanning tree.
• Device priority participates in the calculation of the spanning tree. The device priority can be set separately based on the spanning tree instance to which it belongs, and different instances can be configured with different priorities.
• If you do not configure parameter instance instance-id, the configuration takes effect only on the CIST instance.
• The device supporting Multiple Spanning Tree Protocol (MSTP) can have different priorities in different spanning tree instances.

Example

To set the priority of the device in spanning tree instance 1 to 4096, do as follows:

huawei(config)#stp instance                                                     
{ INTEGER<0-16> }:1                                                          
{ priority<K>|root<K> }:priority                                                
{ integer<U><0,61440> }:4096                                                    
                                                                                
  Command:                                                                      
          stp instance 1 priority 4096 

To restore the default priority of the device in spanning tree instance 1, do as follows:

huawei(config)#undo stp instance                                                
{ INTEGER<0-16> }:1                                                          
{ priority<K>|root<K> }:priority                                                
                                                                                
  Command:                                                                      
          undo stp instance 1 priority  

System Response

• The system does not display any message after the command is executed successfully.

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