I'm currently working on my Raspberry Pi, running Raspbian, trying to connect to a network without password using iwconfig.

ifconfig wlan0 results : ifconfig wlan0

wlan0     Link encap:Ethernet  HWaddr b8:27:eb:33:09:43
          inet addr:  Bcast:  Mask:
          inet6 addr: fe80::74f6:3f1d:f617:df31/64 Scope:Link
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1089 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:154874 (151.2 KiB)

and my iwconfig wlan0

wlan0     IEEE 802.11  Mode:Master  Tx-Power=31 dBm
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off

My script is quite simple (and the wifi's ESSID is "aaa"):

ifconfig wlan0
iwconfig wlan0 essid aaa 
dhclient wlan0

When I try to connect just by using sudo iwconfig wlan0 essid aaa i got an error:

Error for wireless request "Set ESSID" (8B1A) :
    SET failed on device wlan0 ; Operation not supported.

I can see with the GUI that the symbol of the wifi start to blink, like the Raspberry was trying to connect to the network, but it stay like the previous state (unconnected/connected to another essid) At the end of the script I get a message "RTNETLINK answers: File exists". I already did

sudo ip addr flush dev wlan0

to erase it, the message disapears but I'm still not connected

Do you have any idea to help me?

1 Answer 1


You should first stop wpa_supplicant and hostapd from running via:

sudo killall wpa_supplicant
sudo killall hostapd

Then bring down the wlan0 Interface:

sudo ifconfig wlan0 down

Switch the wlan0 interface from master to managed mode:

sudo iwconfig wlan0 mode managed

Bring the wlan0 interface up again:

sudo ifconfig wlan0 up

And now you should be able to connect to the open Access Point via

sudo iwconfig wlan0 essid aaa 
  • When I try to stop wpa_supplicant i get a "no process found" error. Then I try iwconfig wlan0 essid aaa and I got a "Error for wireless request "Set ESSID" (8B1A) :" error. I don't relly know why, I keep looking Commented Jun 1, 2018 at 10:08
  • Did you use sudo iwconfig wlan0 essid aaa or without sudo? Because without sudo you get the exactly same error you mention.
    – oh.dae.su
    Commented Jun 1, 2018 at 11:14
  • I use with sudo,, or I log as root user Commented Jun 1, 2018 at 13:09
  • What does it say in the second line of the error message, after Error for wireless request "Set ESSID" (8B1A) : ?
    – oh.dae.su
    Commented Jun 1, 2018 at 13:41
  • Could you maybe also post the Output of ifconfig wlan0 and iwconfig wlan0 inside your question right before you try to connect to the Access Point aaa?
    – oh.dae.su
    Commented Jun 1, 2018 at 13:48

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