# Global Configuration

Port > Configure > Spanning Tree

This dialog box provides spanning tree information for this port. The following data is displayed:

- Module Number (moduleIndex)

- Port Number (portIndex)

- Spanning Tree Type (stpxSpanningTreeType)

- Loop Guard (stpxLoopGuardConfigMode / stpxLoopGuardConfigEnabled)

- Fast Start Mode (stpxFastStartPortMode / portSpantreeFastStart)

- Fast Start BPDU Guard (stpxFastStartBpduGuardEnable)

- Fast Start BPDU Filter (stpxFastStartBpduFilterEnable)

Do one of the following:

- Click OK to continue.

- Click Apply to save the changes in the dialog box.

- Click Cancel to close the dialog box.

- Click Refresh to update the contents of the dialog box.

- Click Print to print the contents of the dialog box.

- Click Help to access online help.

Module Number (moduleIndex)

Module number for this port.

Port Number (portIndex)

Numerical identifier assigned to this port.

Spanning Tree Type (stpxSpanningTreeType)

Actual mode the spanning tree protocol runs in on this device. There are four modes:

- PVST+ (Per VLAN Spanning Tree+ Protocol)

- MISTP (Multiple Instance Spanning Tree Protocol)

- MISTP–PVST+ (with the tunneling scheme enabled)

- MST (IEEE 802.1s Multiple Spanning Tree)

Loop Guard (stpxLoopGuardConfigMode / stpxLoopGuardConfigEnabled)

Indicates whether the Loop Guard feature is enabled on this port. This configuration is applied to all spanning tree instances in which this port exists.

If this device is running the Catalyst OS version 7.1 (1) or later, there are 3 possible values for this object: enable, disable, and default. Otherwise, there are only 2 valid values: enable and disable.

Fast Start Mode (stpxFastStartPortMode / portSpantreeFastStart)

Indicates whether the Fast Start feature is enabled on this port. A port with fast start enabled is immediately put in the forwarding state when the port is detected by the spanning tree, rather than starting in the blocking state, which is the normal operation.

If this device is running Catalyst OS version 7.1 (1) or later, there are 4 possible values for this object: enable, disable, enableForTrunk, and default. Otherwise, there are only 2 valid values: enable and disable.

Note: This field is read-only on voice ports, and will not appear on ATM ports.

Fast Start BPDU Guard (stpxFastStartBpduGuardEnable)

Indicates whether BPDU Guard for Spanning Tree Port Fast Start feature is enabled or not.

Fast Start BPDU Filter (stpxFastStartBpduFilterEnable)

Indicates whether BPDU Filtering for Spanning Tree Port Fast Start feature is enabled or not.