Ubuntu Has Regained Its Wifi Layer 2 Tracing Functionality

Back in February I noticed that layer 2 Wifi tracing on my Intel Centrino Core Duo based Toshiba notebook from 2009 stopped working after upgrading to Ubuntu 15.10. This had me a bit worried but it looks like it is back with Ubuntu 16.04!

Before proceeding here’s a quick summary of how to activate layer 2 Wifi tracing in a shell (more details here). Starting with Ubuntu 16.04, network interfaces use a new naming nomenclature. Gone are the days of wlan0, say hello to wlp3s0. Easy. Thanks to Systemd for such wonderful device names:

sudo ifconfig wlp3s0 down
sudo iw dev wlp3s0 interface add mon0 type monitor
sudo ifconfig wlp3s0 up

# Now start Wireshark and trace on 'mon0'

# In addition, 'wlp3s0' can be brought up again to lock to a specific channel. To get the IP layer back up and running kill the dhcpd task which will force an auto-restart and IP address assignment.

With Ubuntu 16.04 the procedure works again on two notebooks I tried, a Lenovo E330 and a Lenovo X230, both equipped with an Intel Wifi card, the later one with an Intel 6205 (Taylor Peak) 5 GHz capable module.

Good stuff, so my Wifi tracing capability is secured again for the next few years.

(P.S.: Yes, I do see the reason why network interfaces are now named the way they are by Systemd and it makes sense. It just doesn’t look very nice anymore and interface names are certainly not as easy to remember as they used to be).