Problems with aircrack-ng

Question

I'm trying to crack an wifi, but when i type sudo airmon-ng start wlan0 it shows this:

Found 4 processes that could cause trouble.
If airodump-ng, aireplay-ng or airtun-ng stops working after
a short period of time, you may want to kill (some of) them!

PID Name
463 avahi-daemon
475 avahi-daemon
683 NetworkManager
756 wpa_supplicant

Interface   Chipset     Driver

wlan0       Broadcom    wl - [phy0]mon0: ERROR while getting interface flags: No such device

                (monitor mode enabled on mon0)

Then, when I type sudo airodump-ng mon0 for the list with available BSSID it shows this:

sudo airodump-ng mon0
Interface mon0: 
ioctl(SIOCGIFINDEX) failed: No such device

What can cause this?

This is my wconfig:

wlan0     IEEE 802.11abg  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off

ppp0      no wireless extensions.

lo        no wireless extensions.

My OS is 14.10. My Laptop is Aspire 5745G.

Answer 1

When you run sudo airodump-ng mon0, it shows:

Interface mon0:  
ioctl(SIOCGIFINDEX) failed: No such device

because you don't have that interface. Instead you have:

Interface   Chipset     Driver
wlan0       Broadcom    wl - [phy0]mon0: ERROR while getting interface flags: No such device
            (monitor mode enabled on mon0)

So try using:

sudo airodump-ng wlan0

By the way, your output said:

wl - [phy0]mon0: ERROR while getting interface flags: No such device

because you have a very old version of aircrack-ng. Make sure you installed the latest version of aircrack-ng package.

You're not alone in this BTW, another question ("ERROR while getting interface flags: no such device") has the same issue with yours.

Hope this helps.

Answer 2

The first error seems to indicated that Network Manager is already using wlan0 (in addition to wpa_supplicant and the other processes).

You don't have an interface called mon0, so that's why you get the second error.

You should be able to use aircrack if you don't use wifi via Network Manager (you can try stopping network manager and then running the command). Note that if Network Manager is not running, you have to handle the wifi configuration yourself.

You could also try adding a virtual interface to your wireless phy with iw. To do this, look at the output of "iw phy". My wifi card is phy0, so:

"sudo iw phy phy0 interface add mon0 type monitor"

Then retry the second command.

You can get an idea of what your card supports with "iw phy phy0 info". Again, replace phy0 with the correct argument. Check that it supports monitor mode if you have problems adding a monitor interface.

I noticed you have a broadcom card, so monitor should be supported. You can check your wifi card support here http://wireless.kernel.org/en/users/Drivers

Answer 3

Run this before using aircrack-ng:

sudo ifconfig <interface(wlan0)> down

Then use aircrack-ng. If it doesn't work try this:

sudo airmon-ng check kill

Then:

airmon-ng start <interface(wlan0)>

Answer 4

Was seeing the same error running precompiled binaries on Raspian and ended up building from source to get past it. I used these instructions, which I'm quoting below (with some code formatting added):

Raspberry Pi: How to install aircrack-ng suite

How to install aircrack-ng suite to your Raspberry Pi.

Installing aircrack-ng suite (for airodump-ng, airbase-ng and so on) is really easy and pretty quick:

First we want to install libssl-dev or we will have some problems with aircrack-ng:

apt-get -y install libssl-dev

Now we can install aircrack-ng (We need working internet connection here):

wget http://download.aircrack-ng.org/aircrack-ng-1.2-beta1.tar.gz
tar -zxvf aircrack-ng-1.2-beta1.tar.gz
cd aircrack-ng-1.2-beta1
make
make install

This will download aircrack-ng package from aircrack-ng.org site and extract it to a aircrack-ng-1.2-beta1 directory and then install it from there.

Now you probably want to update OUI thingy with command:

airodump-ng-oui-update

and then you need to install iw to get your wifi card to monitor mode:

apt-get -y install iw

after that command:

airmon-ng start wlan0

Should start wlan0 on monitor mode as mon0 and we can try airodump-ng:

airodump-ng mon0

And we should see some info about current wireless networks around us.

Answer 5

This conflicting behavior comes from network manager. If you don't want to use sudo airmon-ng check kill (which totally stop network manager) you can add an exception for your mon0 interface as explained here: aircrack-ng : airmon-ng stop working after updating to 15.04 ( ioctl(SIOCSIWMODE) failed: Device or resource busy )

1.Open network manger configuration file with root privileges

sudo gedit /etc/NetworkManager/NetworkManager.conf

2.Add the following lines at the end of your file to create an exception for your mode monitor interfaces.

[keyfile]
unmanaged-devices=interface-name:mon*;

Once you saved the changes effects are immediate and airmon-ng will be able to handle properly the interface Be aware that you are using an outdated version of aircrack-ng (the one from ubuntu repositories I guess) I strongly suggest you to install a more recent version (in this case the mode monitor interface will be called wlan0mon and not mon0 anymore) Go to aircrack-ng website to download the latest stable release (Aircrack-ng 1.2 RC 4 ): aircrack-ng website