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Can’t sniff wifi


I want to sniff wifi packets with wireshark but monitor mode seems to fail. I'm using backtrack 5 and an alpha AWUS036H wifi usb card, i try to sniff my own box without encryption.

Here is what i'm doing to activate monitor mode :

[email protected]:~# airmon-ng start wlan0

wich seems to be working :

[email protected]:~# iwconfig mon0
mon0 IEEE 802.11bg Mode:Monitor Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:on

However when i start capturing on mon0 in wireshark i'm only getting broadcast packets. In capture options the "capture packets in monitor mode" option is grayed out.

I do not understand what's going on. Any Ideas ?

asked 05 Feb '12, 05:16

kyori's gravatar image

accept rate: 0%

use airodump-ng and look at the tracefile saved from it, if thats working it might be a wireshark issue, if not make sure your wlan0 device is NOT used to connect to a wireless network, which might corrupt your monitor mode settings on mon0

(06 Feb '12, 05:02) Landi

At least with some versions of Linux and some devices and drivers, you can run in monitor mode when connected to a wireless network. Given the wlan0 and mon0, the driver for the adapter is probably a mac80211 driver, so I wouldn't be surprised if it supported running in monitor mode when connected to a wireless network.

(06 Feb '12, 09:06) Guy Harris ♦♦

Right, that should work - I was just suggesting there might be a conflict if the card already seems to be in mon. mode but the issues appear it might be a conflict where normally there shouldn't be one

(07 Feb '12, 00:39) Landi