Performing a network trace

Overview

This article explains how to perform a network trace that Lexmark Technical Support may request for evaluation by 3rd level support and product engineering teams. A network trace is a useful tool for diagnosing printer-related network communication issues.

Requirements

• Hub
• A hub should be used to capture a network trace.
• Why? Hubs allow each and every port to see all the network traffic going to other ports on the device. In contrast, a switch, router, or smart hub directs network traffic to specific destinations (ports), which may prevent a comprehensive network trace and thus not provide a true picture of the network's condition.

Note:  If a hub is not available, you may be required to turn on 'port mirroring' in order to obtain a successful network trace. Please refer to the User's Guide for the switch or router for further details.

• Two additional Ethernet cables
• You will need two additional functioning network cables to perform this procedure.
• Network trace application
• This example uses a recommended network trace application (network packet analyzer) called Wireshark. Please visit http://www.wireshark.org to download the application. Go to http://wiki.wireshark.org/Security and http://www.wireshark.org/docs/wsug_html_chunked/ for information regarding security, Windows Vista installation, and software usage.

Procedure

Printer/computer-to-hub connection and network trace

1. Disconnect the Ethernet cable from the printer's network port and plug this cable into the uplink port on the hub.

   Note:  This takes into account that the printer's Ethernet cable is connected to a switch on the network.

   If unsure about the connection method:

   • Try connecting the cable to any port adjacent to Port 1 to see whether the Ethernet LED illuminates.
   • If the LED does not illuminate, try Port 1, which is often the Uplink port on the hub.
   • Also, look for the presence of an uplink switch or button on the hub to check that it is active or turned ON.


2. Take one of your Ethernet cables and connect one end to the printer and the other end to an available port on the hub.



3. Disconnect the existing network cable from the computer performing the trace and, using your second extra cable, connect the computer to the hub.

   Note:  You can reconnect the original cable after capturing the network trace.



4. There are now three Ethernet cables connected to the hub. Click here for an image.



5. After installing and opening Wireshark, click this icon to initiate the trace, or click on Capture > Interfaces from the menu bar.



6. Select Start next to the network interface that is showing an IP address.

   Note:  This should be the host computer referred to in Step 4.



7. Click OK to begin the trace and perform the function related to the failing printer, multifunction product (MFP), or All-In-One (AIO). See this image.



8. When you are ready to stop the trace, click this icon or click Capture > Stop from the application's menu bar.



9. If you successfully emulated the network communication anomaly or failure, click this icon to save the trace. Alternatively, click File > Save As from the menu bar.



10. Submit the trace information to your Lexmark Technical Support representative. Include the printer's IP address (network settings page) and computer ipconfig information.

After the capture

1. Disconnect both ends of the Ethernet cable connected from the hub to the computer that took the network trace. Place this in the box, if provided.



2. Disconnect both ends of the Ethernet cable connected from the hub to the printer. Place this in the box, as above.



3. Disconnect the Ethernet cable connected to the hub. This should be the cable that was previously connected to the printer. Reconnect this cable to the printer.



4. Reconnect the Ethernet cable that was previously connected to the computer that took the network trace to the computer.



5. Place the hub and its power supply back in its box or original location.

Related article

How to Capture an IPDS Trace in AS400/OS400 Environments (2011)