Posts

Wiperf: A wireless client performance probe mode on the WLAN Pi

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I've had a number of occasions when it would have been really useful to deploy a wireless client device on a WLAN to monitor performance over time from a client perspective. Too often, when troubleshooting a wireless network, everything looks fine from the data provided by your infrastructure kit, but the user experience is a whole different story. Unfortunately, when this requirement has arisen, persuading anyone in the organization in which I was working to invest in a wireless probe-type solution has been an uphill battle.

Around 18 months ago I got to the point when working on an issue that I could not progress and had no choice but to roll my own rudimentary client probe solution. It was a Python script installed on a Raspberry Pi acting as a client on a particular SSID that was having issues. It reported wireless connectivity data and a few client tests (e.g. speedtest & ping) to a Google spreadsheet. The same code also ran on a WLAN Pi, so that I could have two prob…

How to Burn a New Image on Your WLAN Pi

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I'm often asked how to burn a new image on to the WLAN Pi, so thought a video might be useful for anyone who wants to update their WLAN Pi image.
When we release new code for the WLAN Pi, it's released as a single image file that needs to be burned on to the micro-SD card of the WLAN Pi. This video provides a practical demonstration of the process.

 Here are the links for the web sites shown in the video:

Direct link to Youtube video: https://youtu.be/sD4WlNyyWDsWLAN Pi image repo: https://github.com/WLAN-Pi/wlanpi/releasesbalena Etcher web site: https://www.balena.io/etcher/Get the micro-SD to USB adapter: https://amzn.to/30BO4cx

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My favourite WinFi features

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Ealier this year myself and a few other Wi-Fi pros were lucky enough to be asked to provide some input to a new Wi-Fi scanner application being created by Helge Keck. He called the tool "WinFi" and has now released as a free tool for Windows 10.

WinFi is a feature-packed application that has many pro-level functions that have quickly made it the Wi-Fi scanner of choice on Windows for many wireless LAN pros.

I thought I'd take a few minutes to run through the operation of WinFi and highlight some of my favourite advanced features that you may not have seen yet within the application by creating the video below:


ReferencesApplication home pageVideo LinkHelge Keck on Twitter

Using the WLANPi as a wireless serial console

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One lesser-known feature we added to the WLANPi image in v1.7 is Wi-Fi console that provides a wireless serial console. As this isn't too widely known, I thought I'd put a video together about it. 

The Wi-Fi console feature allows you to hook up a serial cable to the serial port of a piece of nework equipment, then get your WLANPi to broadcast out an SSID you can join from a nearby location.

You can then fire up terminal emulation software on your laptop and access the serial port on the nework equipment from a more comfortable location. Note this is a standard part of the WLANPi image since v1.7 - you do not need to install any additional packages, just follow the instructions in this video to flip your WLANPi in to Wi-Fi console mode.


References YouTube VideoGitHub repo & further information

Understanding Wireless Client Throughput From a Wireshark Capture

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I recently created a  video to look at how we understand the data throughput of a wireless client from an over the air Wireshark capture. We take a look at using the I/O Graph feature in Wireshark to achieve this.

You can view the video below:


References:
YouTube video linkMetageek Wireshark profile

Wireshark Showing FCS Fields as "Unverified" in Captures

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In a recent Wireshark 3.0.6 capture I noticed that FCS values for captured wireless frames were showing as "Unverified". I wasn't sure why this was the case, as I'm sure that Wireshark usually shows a "good" or "bad"  FCS indication. The image below demonstrates what I saw:

After some googling, I found a note that the FCS check was disabled by defaut in Wireshark 3.0.x as some NICs report the FCS check incorrectly. 
The following process details how to re-enable the check: 
Go to Edit -> Preferences -> Advanced in Wireshark. Enter "wlan.check" in the search bar:

Double click on the "False" word for the attribute "wlan.check_checksum". This will toggle it to "True" (make sure you click on the "False" word, not anywhere else on the line). 

Hit OK and see the change immediately in your capture decode:

Hope this quick note may help someone in the future (...probably me when I've forgotten how …