I am connected to my home wifi network using Ubuntu 10.10. The protection is WPA2-auto. I want to capture packets from it.
$ sudo iwconfig wlan0 mode monitor
$ sudo wireshark
I try to capture from wlan0.
Am connected to the wifi network with an android phone and browsing websites.
However I am unable to see unencrypted http packets.
I select Edit|Preferences|Capture|Protocols and select 802.11 and set the checkbox to yes for 'decrypt packets'. Still nothing.
Solution: run airmon-ng from the aircrack-ng project to set the wireless card into monitor mode. (this was pointed out by a Wireshark developer on the mailing lists). Apparently iwconfig does not work properly as it has issues on Ubuntu.
airmon-ng start wlan0
This will set it into monitor mode and create interface mon0.
After this, I was able to capture off the mon0 interface using Wireshark.