How to Monitor Cable Modem Traffic

By Shea Laverty

Ethernet cables plugged into a switch
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Monitoring the activity and traffic on your cable modem is an important part of any network administrator's job -- even if the network is in the home. By keeping tabs on your modem's activity, you can identify potential issues in your service, unauthorized access and troubleshoot your connection. There are a few methods you can use, depending on how much you're willing to spend and the level of detail your diagnostics require.

Via Windows

You can get a very basic look at your modem's activity through Windows's networking tools in the Control Panel. Open the Power User menu by pressing Windows-X, then select "Control Panel | Network and Internet | View Network Status and Tasks | Change Adapter Settings" and double-click the icon for the modem in question. This will open a dialog window with basic information on the connection, including speed, connection duration and signal strength if you're connected to it wirelessly. You'll also see indications of how much data has been sent and received by the modem.

Third-Party Software

Deeper analysis requires a more detailed assessment of your modem's activity than the basic information provided by Windows. For this information, you'll need third-party software like Packetloop, OpManager, GFI Remote IT or PRTG Network Monitor. These programs are enterprise-level analytic software for network management, in addition to providing other information like data packet source, threat indications and other IT security concerns. While PRTG offers a free version for personal use, the others offer only free trials of their paid products. Depending on how robust an analysis and any additional services and information you require, each program offers its own benefits. Find the right fit for your needs by comparing each product.

Reasons to Monitor Activity

Information regarding your modem's activity can be useful for troubleshooting connection issues and identifying unauthorized usage of your connection. Sudden spikes in activity when no one on your network is using the modem can indicate an unauthorized user, while the speed and connection data can be used to assist in diagnosing issues with the modem or connected computers. You can also make sure the speed you are receiving is the speed promised by your ISP.

Privacy Considerations

Privacy concerns may arise as a result of monitoring network activity. While the information provided may be limited depending on the software you use, you will be able to identify traffic spikes and when they occur. If your software identifies which user is accessing the network at any given time, you can identify who is surfing at what time. This may be invasive to others in your home or business, who may not appreciate knowing that their activity is being monitored.