Quick troubleshooting network bottleneck on Windows

Have you ever looked for a tool similar to iftop to Windows? Where you could quickly see where the network bottleneck or even a malware is coming from/to?

Heitor Lessa
heitorlessa
2 min readJun 19, 2013

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We have a wide range of softwares for troubleshooting in Linux ie built-in or not, however when it comes to Windows environment you can mostly find sharewares and only few freewares that really do the job. So, we will be showing in this quick tip an application called Show Traffic which is old (2008) but gold, and can save you from some headaches.

Keep in mind that we are here referring to a bottleneck in a specific system where there is a high network traffic coming from/to. For a deeper network bottleneck analysis, please use proper Monitoring tools for this scenario.

To get started, go to the download link here and install in few steps. However, for those interested in getting the source code as it is an Open Source project — please find here.

Open up the software and choose your interface that will be put in promiscuous mode to capture all packets:

Troubleshooting network bottleneck on Windows — Choosing the network adapter

Click on the Start button and in few seconds you should see the network activity as shown:

Troubleshooting network bottleneck on Windows — High traffic

As we can see above, there’s a big difference between the packets/traffic on top with the others one below, so we can quickly find a network bottleneck here. As a result, we conclude that there is a connection to a specific IP using port 80 (HTTP), and the bottleneck is on download link (second line).

For those who prefer to resolve names and TCP ports to a known protocol, please use the options below:

Troubleshooting network bottleneck on Windows — Resolving names and tcp ports

That’s it ! It’s a really quick tip that you may find useful on a daily basis.

Of course, we can also use several other tools to do the same work, but I personally believe that this is by far the easiest and quickest way to find a network bottleneck like this, and I also used several times this tool to find worms together with port scanners + wireshark.

Hope that helps!

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Heitor Lessa
heitorlessa

Spiritualist, world citizen and happened to be working as Specialist Solutions Architect focused on Serverless @ AWS