Using Layer 2 Trace

In troubleshooting situations, it is often critical to understand the path that network data takes to access another network device. The Layer 2 Trace tool provides a method to trace the physical network path from one device to another.

Using previously discovered network connectivity data, the Layer 2 Trace tool finds the path between the two devices and then displays each network interface that is used to build the path. The trace tool also allows for a quick check of the status and availability of each step along the layer 2 path.

The Layer 2 trace tool is accessible from the WhatsConnected and WhatsUp Gold console.

To run the Layer 2 Trace tool from WhatsConnected console:

From WhatsConnected:

1. From the main menu of the WhatsConnected console, select Tools > Layer 2 Trace. The Layer 2 Trace dialog appears.

   Tip: You can also view Layer 2 Trace tool from the WhatsConnected console shortcut menu. Click (Layer 2 Trace shortcut icon). The Layer 2 Trace dialog appears.

From WhatsUp Gold:

1. From the WhatsUp Gold console, select a device group map view.
2. Right-click on any device in the map view. The right-click menu appears.

   Click Layer 2 Trace. The WhatsConnected - Layer 2 Trace dialog appears.

3. Click Source. The Select Source Device dialog appears.
4. Select a starting device for the layer 2 trace, then click OK. The IP address selection appears in the Source Device box.

   Tip: You can use the Device Filter list to view specific device types.

5. Click Destination. The Select Destination Device dialog appears.
6. Select a destination device for the layer 2 trace, then click OK. The IP address selection appears in the Destination Device box.

   Tip: You can use the Device Filter list to view specific device types.

7. Click Trace. The step-by-step layer 2 path from the source device to the destination device displays in a list format. The results of the search are displayed in the Layer2 Trace tool list columns.
   • Device. Lists the devices that the network path traverses.
   • IP Address. Lists the IP address of each device on the network path.
   • Interface Name. Lists the interfaces that the network path traverses.
   • Status. Lists the device status information.

   Note: After a trace is completed, you can click Ping to view the current status of the Layer 2 path. This tool pings each device identified in the trace and uses SNMP to query the interface for its status.

8. Click Clear to remove the information from the Layer 2 Trace table and start a new trace.
   - or -
   Click Close to close the dialog.

To run the Layer 2 Trace tool from WhatsUp Gold console:

1. From the WhatsUp Gold console, right-click a device in a Device View or Map View tab. The right-click menu appears.
2. Click Layer 2 Trace. The Layer 2 Trace dialog appears.
3. Click Source. The Select Source Device dialog appears.
4. Select a starting device for the layer 2 trace, then click OK. The IP address selection appears in the Source Device box.

   Tip: You can use the Device Filter list to view specific device types.

5. Click Destination. The Select Destination Device dialog appears.
6. Select a destination device for the layer 2 trace, then click OK. The IP address selection appears in the Destination Device box.

   Tip: You can use the Device Filter list to view specific device types.

7. Click Trace. The step-by-step layer 2 path from the source device to the destination device displays in a list format. The results of the search are displayed in the Layer2 Trace tool list columns.
   • Device. Lists the devices that the network path traverses.
   • IP Address. Lists the IP address of each device on the network path.
   • Interface Name. Lists the interfaces that the network path traverses.
   • Status. Lists the device status information.

   Note: After a trace is completed, you can click Ping to view the current status of the Layer 2 path. This tool pings each device identified in the trace and uses SNMP to query the interface for its status.

8. Click Clear to remove the information from the Layer 2 Trace table and start a new trace.
   - or -
   Click Close to close the dialog.
   - or -
   Click Save to open the Save Up Dependency dialog. This dialog provides a list of Layer 2 paths, found in the Layer 2 trace, that can use up dependencies in WhatsUp Gold polling dependency rules. For more information, see Dependencies overview in the WhatsUp Gold Help.

See Also Using WhatsConnected Tools About WhatsConnected Tools Using IP/MAC Finder Rebuild Connectivity Classify Devices Show Discovery Alerts Using the Device Viewer