# Edit Buffer

To access the Edit Buffer dialog box:

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

2. Click Edit Buffer.

From this dialog box, you can modify the MST instances configured on this device.

The following data is displayed:

- MST Instance (stpxMSTInstanceEditIndex)

- VLANs Mapped (stpxMSTInstanceEditVlansMapped)

Note: This dialog box is available only on devices where the spanning tree type is set to MST.

You may see a message which states that the edit buffer is locked by a non-SNMP (command line interface) user. In order to make changes:

1. Click Yes to release the edit buffer and discard any changes the non-SNMP user made.

2. Enter your changes.

3. Click OK. The edit buffer is updated with the latest VLAN mappings and locked by the SNMP user.

Do one of the following:

- Click Modify to specify the VLANs mapped to the selected MST instance.

> Note: MST instance 0 cannot be modified.

- Click Commit to commit the edit buffer contents into the device's NVRAM and release the edit buffer lock.

- Click Rollback to discard the edit buffer contents and release the edit buffer lock.

- Click Cancel to close the dialog box.

- Click Help to access the online help.

MST Instance (stpxMSTInstanceEditIndex)

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 (stpxMSTInstanceEditVlansMapped)

Indicates the VLANs mapped to the selected MST instance.