The Spanning Tree Extended Port Table contains information about STP ports that are monitored for flapping. Flapping occurs when STP ports are constantly varying between listening to learning to forwarding. This may cause detrimental traffic loss.
The Spanning Tree Extended Port Table contains port stability information, whether the port is filtering BPDUs, the amount of BPDUs sent, and the amount of BPDUs received. BPDUs can be filtered on ports only where STP is disabled.
Ports are considered stable if they receive a specific amount of BPDUs within a specific time period. Damping occurs when an STP port does not advertise to its neighboring port.
The Spanning Tree Extended Port Table has the following sub-menus/commands:
Port — Indicates the port number to which the STP applies.
Damp Enabled — Specifies whether Bridge Protocol Data Units (BPDU) received are monitored on the port in fixed intervals. The default is 10 seconds. Monitoring BPDUs helps determine if the port is stable. The possible values are:
True — Indicates that port damping monitoring is enabled.
False — Indicates that port damping monitoring is disabled.
Damp Stable — Determines if the port is stable. The possible values are:
True — Indicates that the port is currently stable.
False — Indicates that the port is currently unstable and dampened.
Filter BPDU — Indicates if BDPUs are filtered on a port.
BPDU Sent — Indicates the amount of BPDUs sent from the specified port.
BPDU Received — Indicates the amount of BPDUs received on the specified port.
To edit an Spanning Tree Extended Port Table entry:
Click . The Spanning Tree Port Extended Table Edit window is displayed.
Edit the required table entry fields and click . The Spanning Tree Port Extended Table window is displayed.
Click . When the Status field displays “Finished!”, the fields are confirmed as modified.