Objective

VLAN to Multiple Spanning Tree Protocol (MSTP) Instance page allows you to map each VLAN to a Multiple Spanning Tree Instance (MSTI). In order for the devices to be in the same region, they need to have same mapping of VLANs to MSTIs. For those VLANs that are not particularly mapped to one of the MSTP Instances, the switch automatically maps them to the Core and Internal Spanning Tree (CIST) instance. The CIST instance is MSTP Instance of 0.

This article explains the steps for the mapping of VLANs to MSTIs.

Applicable Devices

- Sx500 Stackable Managed Switch

Software Version

- v1.2.7.76

VLAN to MSTP Instance Settings

Step 1. Use the web configuration utility and choose Spanning Tree > VLAN to MSTP Instance. The VLAN to MSTP Instance page opens.

Note: The same MSTP Instance can be mapped to more than one VLAN, but each VLAN can have only one MSTP Instance associated with it. It contains the following fields:

- MSTP Instance ID — All MSTP Instances are shown.

- VLANs — All VLANs belonging to the MSTP Instances are shown.

Step 2. To add a VLAN to an MSTP Instance, click the radio button for the MSTP Instance and click Edit. The Edit MSTP Instance to VLAN page opens.

Step 3. Choose the MSTP Instance from the MSTP Instance ID drop-down list.

Step 4. Enter the VLANs that need to be mapped to this MSTP Instance.

Step 5. Click the Add radio button to add the VLAN to MSTP Instance. Click the Remove radio button to remove VLAN to MSTP Instance.

Step 6. Click Apply by which MSTP VLAN mappings are defined and the Running Configuration is updated.