Global Configuration

Device > Configure > Spanning Tree

Use this feature to set spanning tree parameters that enable the device's learning bridge to dynamically halt loops in the network (by shutting down selected bridge interfaces) before creating a spanning tree path.

The following data is displayed:

Do one of the following:


Spanning Tree Mode (stpxSpanningTreeType)

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


Spanning Tree Path Cost Mode (stpxSpanningTreePathCostMode)

Indicates the spanning tree path cost mode configured on this device. This mode applies to all instances of the spanning tree protocol running on the device. When the value of this field is changed, the path cost of all ports is reassigned to the default path cost value, which is based on the new spanning tree path cost mode and the speed of the ports.

If the selected STP mode for the device is "pvst+", the value of this field can be changed between "long" and "short". If the selected STP mode for the device is "mistp", "mistp-pvst+", or "mst", the default switch uses the long path cost.

Note: When the value of this field is set to "long", the path cost you can specify ranges from 1 to 268435456. When the value of this field is set to "short", the path cost you can specify ranges from 1 to 65545.

To set the path cost per port value:

  1. Select Port > Configure > Bridge.

  2. Click Bridge Details.


UplinkFast Mode (stpxUplinkFastEnabled)

Displays whether STP UplinkFast is enabled on the device, as true or false.

Note: This field is not displayed when Spanning Tree Mode is set to "MST".


UplinkFast Learning Rate (0..32000) (stpxUplinkStationLearningGenRate)

Maximum number of station-learning frames that this device will generate in each 100 millisecond period after an UplinkFast transition. The default is 15.

Note: This field is not displayed when Spanning Tree Mode is set to "MST".


Backbone Fast (stpxBackboneFastEnabled)

Indicates whether the BackboneFast capability is enabled on the device.

Note: This field is displayed when Spanning Tree Mode is set to "PVST+".


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.


Fast Start Default Mode (stpxFastStartGlobalDefaultMode)

Indicates global default mode of Fast Start feature on the device.


LoopGuard Default Mode (stpxLoopGuardGlobalDefaultMode)

Indicates global default configuration mode of LoopGuard feature on the device.


Mac Reduction Admin Status (sysMacReductionAdminEnable)

Indicates whether the Mac Reduction feature, which reduces the number of MAC addresses used in bridge identifier, is administratively enabled on the device or not.

Note: This object is only valid for Catalyst 6000 devices.


Mac Reduction Oper Status (sysMacReductionOperEnable)

Indicates whether the Mac Reduction feature, which reduces the number of MAC addresses used in bridge identifier, is operationaly enabled on the device or not.

If the value of this object is true(1), the accepted values for dot1dStpPriority in BRIDGE-MIB should be in multiples of 4096 plus the bridge instance ID (such as VlanIndex). Changing this object value may cause the values of dot1dBaseBridgeAddress and dot1dStpPriority, in BRIDGE-MIB, to be changed.

Note: This object is only valid for Catalyst 6000 devices.