Posts

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 …

Wireshark Plugin To Capture Wireless Frames Using a WLANPi (Windows 10)

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Want to be able to capture wireless frames via a WLANPi using just Wireshark on your Windows 10 machine? ...And be able to configure the capture configuration on the WLANPi using just Wireshark too?  Read on... (or checkout the video here)


Earlier this year, I put out a command-line script called WLANPiShark that allowed Windows 10 users to configure a WLANPi and initiate a frame capture stream in to Wireshark. Though a little clunky, it worked quite reliably for most of the time and, judging by feedback I received, was quite popular.

As Windows users, we've always been the poor cousins to our Apple brethren who are able to use their Macbook to capture over the air using the internal NIC card of their Mac in monitor mode. Getting a low cost adapter that could be put in to monitor mode on a Windows machine was as rare as hen's teeth.
Having access to the WLANPi and being able to fire up WLANPiShark opened up wireless capturing to many folks who have to use Windows machines, but…

Wireless Analysis Resources

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Wireless traffic capture and analysis can be a tricky business and is often seen as something of a dark art to newcomers to the world of Wi-Fi. There are a huge variety of options when considering how to capture wireless traffic over the air, with many of the solutions being paid-for options that may be out of reach for many individuals.

Many people approaching wireless analysis may already be familiar with Wireshark, based on their previous experience on wired networks, where they may have used it for troubleshooting and analysis purposes.  They may wonder if they can use Wireshark for their initial foray into wireless analysis.  Using Wireshark for wireless capture and analysis on Wi-Fi networks can be a little tricky and presents the newcomer with a whole new slew of frame types to learn.

There are many good articles, videos and podcasts out there looking at wireless analysis, particularly if Wireshark is your tool of choice. I thought it would be good to pull them together in one…