"ERROR while getting interface flags: no such device"

Question

The command

airmon-ng start wlan0

gives as output

Found 5 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
3258   wpa_supplicant
4175   NetworkManager
4180   dhclient
4190   avahi-daemon
4191   avahi-daemon 
Process with PID 4180 (dhclient) is running on interface wlan0

Interface       Chipset       Driver  

wlan0           Unknown       wl - (phy0]mon0: ERROR while getting interface flags: Onjuist apparaat  

                              (monitor mode emabled on mon0)

and then I type

ifconfig mon0 down

and I get this error:

ERROR while getting interface flags: no such device

The error will probably start at airmon-ng start wlan0.

Answer 1

To quote from the aircrack-ng site:

This means you have an old version of airmon-ng installed. Upgrade to at least v1.0-rc1.

They add chipset information/support in their newer releases, as well as incorporate patches.

To upgrade to the latest version of aircrack-ng, please follow the steps in this answer.

Answer 2

There are two possible reasons for this error I came through so far.

1. Device is in use: Kill all processes mentioned which could cause trouble, e.g.

   kill -9 3258 (kills your wpa_supplicant)

2. Update to latest aircrack-ng version: The documentation suggests to update to the latest version from svn.

If this does not help, you should provide more information/details on the issue.

Answer 3

The problem is with the name of the interface

So, type airmon-ng to start your wireless interface in monitoring mode

Then type airmon-ng check kill to kill all the interfering processes

Now type

airodump-ng wlan0mon

instead of typing

airodump-ng mon0

I hope this will work, if not please comment