# Modify MST Instance

To access the Modify MST Instance dialog box:

1. Select Device > Configure > Spanning Tree > Multiple Spanning Tree (MST) > Instance Mapping.

2. Click Edit Buffer.

3. Select a MST instance and click Modify.

From this dialog box, you can modify the values for the following objects:

- MST Instance (mstInstanceEditIndex)

- VLANs Mapped (mstInstanceEditVlansMapped)

Do one of the following:

- Click OK to continue.

- Click Cancel to close the dialog box.

- Click Help to access online help.

MST Instance (mstInstanceEditIndex)

Unique identifier for an MST instance that is supported by the device. Values can range from 0 to the value of MST Max Instance Number.

VLANs Mapped (mstInstanceEditVlansMapped)

Indicates the VLANs mapped to the selected MST instance.

Note: Valid VLAN values range from 1 to 4094.