iwlist set essid -> Operation already in progress

Question

I am trying to connect to an AP with iwconfig in the command line:

sudo iwconfig wlan0 essid "APname"

Every time I execute it, I got the following errors:

Error for wireless request "Set ESSID" (8B1A) :
    SET failed on device wlan0 ; Operation already in progress.

However, I can't find the reason for saying operation already in progress. I've also tried sudo iw dev wlan0 connect "APname", but the result is the same.

The environment that I use is:

• Ubuntu 14.04 LTS on VMware Player 7.1 on Windows 7 64-bit

• I am using TP-LINK TL-WN722N USB-type WLAN card, which uses ath9k_htc driver.

• ifconfig wlan0 shows:

  wlan0     Link encap:Ethernet  HWaddr aa:ff:cc:22:88:88  
            inet addr:192.168.0.28  Bcast:192.168.0.255  Mask:255.255.255.0
            inet6 addr: ffff::aaaa:cccc:ffff:8888/64 Scope:Link
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            RX packets:467 errors:0 dropped:0 overruns:0 frame:0
            TX packets:160 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000 
            RX bytes:145417 (145.4 KB)  TX bytes:27489 (27.4 KB)
  

• iwconfig wlan0 shows:

  wlan0     IEEE 802.11bgn  ESSID:"currentAP"  
            Mode:Managed  Frequency:2.432 GHz  Access Point: 00:22:66:CC:80:FF   
            Bit Rate=150 Mb/s   Tx-Power=20 dBm   
            Retry  long limit:7   RTS thr:off   Fragment thr:off
            Power Management:off
            Link Quality=48/70  Signal level=-62 dBm  
            Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
            Tx excessive retries:0  Invalid misc:100   Missed beacon:0
  

Solution

You can add iface wlan0 inet manual to /etc/network/interfaces.

Network manager will not manage your wireless network.

But you will need to do ifup wlan0 and ifdown wlan0 manually too.

You can also manage your wireless by Network Manager using nmcli utility.

Comments

[Pilot6]

Probably Network Manger manages this connection. And it is connected. Why are you trying to connect manually? You can do it, but you need to set NM not to do it automatically.

[Jeon]

For research purpose. I need to change APs that a client connects with. I want to make it batch.