VLAN to MSTP Instance

The VLAN to MSTP Instance page enables you to map each VLAN to a Multiple Spanning Tree Instance (MSTI). For devices to be in the same region, they must have the same mapping of VLANs to MSTIs.

Note

The same MSTI can be mapped to more than one VLAN, but each VLAN can only have one MST instance attached to it. Configuration on this page (and all of the MSTP pages) applies if the system STP mode is MSTP. Up to 16 MST instances can be defined in addition to instance zero. For those VLANs that aren’t explicitly mapped to one of the MST instances, the device automatically maps them to the CIST (Core and Internal Spanning Tree) instance. The CIST instance is MST instance 0.

To map VLANs to MST Instances, follow these steps:

Procedure

Step 1

Click Spanning Tree > MSTP > VLAN to MSTP Instance.

The VLAN to MSTP Instance page displays the following fields:

  • MSTP Instance ID-All MST instances are displayed.

  • VLANs-All VLANs belonging to the MST instance are displayed.

Step 2

Click Add to add a VLAN to an MSTP instance, or Edit to edit a VLAN to an MSTP instance.

Step 3

Enter the parameters:

  • MSTP Instance ID-Select the MST instance.

  • VLANs-Define the VLANs being mapped to this MST instance.

Step 4

Click Apply. The MSTP VLAN mappings are defined, and the Running Configuration file is updated.