(Optional) Manually Configuring the Mapping between MSTIs and VLANs

Context

Based on the mappings between MSTIs and VLANs of MSTP, VBST maps each MSTI to a VLAN to establish 1:1 mapping. The 1:1 mapping between MSTIs and VLANs is used only by the switch to determine the VBST forwarding status. This does not mean that VBST supports multi-instance.

The mapping between MSTIs and VLANs can be manually configured or dynamically specified.

You can manually configure the mapping between MSTIs and VLANs on the switch. If a static mapping is also configured for a VLAN, the static mapping takes effect.
After VBST is enabled, the system dynamically allocates instance IDs to existing or new VLANs in ascending order. The dynamically specified mapping cannot be changed manually. After a VLAN is deleted or STP is disabled globally, its mapping is automatically deleted.

When the number of MSTIs that are dynamically specified exceeds the number of protected VLANs, if a VLAN is created, in the configuration file, STP is disabled, for example, stp vlan 100 disable.

The following steps are performed to manually configure the mapping between MSTIs and VLANs.

Procedure

Run system-view
The system view is displayed.
Run stp region-configuration
The MST region view is displayed.
Run instance instance-id vlan vlan-id
1:1 mapping between MSTIs and VLANs is configured.

By default, all VLANs in an MST region are mapped to MSTI 0.

After this step is performed, the dynamic mapping between MSTIs and VLANs cannot be canceled even if VLANs are deleted or STP is disabled globally.
Run active region-configuration
1:1 mapping between MSTIs and VLANs is activated.

The change of 1:1 mapping between MSTIs and VLANs causes VBST recalculation and network flapping. Therefore, it is recommended that you run the check region-configuration command in the MST region view to check whether the parameters of the MST region are set correctly before activating the configuration of the MST region. When determining that parameters of the MST region are set correctly, run the active region-configuration command to activate 1:1 mapping between MSTIs and VLANs.