Can't connect to wireless on Ubuntu Server

Question

I'm having some trouble connecting to a wireless network on Ubuntu Server 12.10. I have the driver installed with ndiswrapper, I can scan with iwlist wlan0 scan, and I'm trying to use wpa_supplicant to configure the interface. However, iwconfig is showing that I'm not connected to an access point.

---

/etc/network/interfaces

# Wireless interface
auto wlan0
iface wlan0 inet dhcp
  wpa-driver ndiswrapper
  wpa-ssid "turkradio"
  wpa-ap-scan 2
  wpa-proto RSN
  wpa-pairwise CCMP
  wpa-group CCMP
  wpa-key-mgmt WPA-PSK
  wpa-psk KEY-FROM-WPA-PASSPHRASE

---

/etc/wpa_supplicant.conf

#ctrl_interface=/var/run/wpa_supplicant
ap_scan=2

network={
    ssid="turkradio"
    scan_ssid=1
    proto=RSN
    key_mgmt=WPA-PSK
    group=TKIP
    pairwise=TKIP
    #psk="KEY"
    psk=ENCRYPTED_KEY
}

---

ifconfig

wlan0     Link encap:Ethernet  HWaddr 08:86:3b:8a:d5:a5  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

---

iwconfig

wlan0     IEEE 802.11g  ESSID:off/any  
          Mode:Managed  Frequency:2.442 GHz  Access Point: Not-Associated   
          Bit Rate:54 Mb/s   Tx-Power:20 dBm   Sensitivity=0/3  
          RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality:0  Signal level:0  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

---

How can I correctly configure my interface?

Answer 1

The following should work:

/etc/network/interfaces file:

auto wlan0
    iface wlan0 inet dhcp
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

/etc/wpa_supplicant/wpa_supplicant.conf file:

network={
    ssid="turkradio"
    psk=ENCRYPTED_KEY
}

You get the encrypted key using the wpa_passphrase command:

wpa_passphrase turkradio key

Then to restart the networking(leave out the sudo if you are root):

sudo /etc/init.d/networking restart

Answer 2

Try using Wifi-Radar to see if it can scan your SSID and connect. You can install it with:

sudo apt-get install wifi-radar

It should be able to help you troubleshoot problems. You might have your key wrong or something else.

Answer 3

Looking at the output from iwconfig there is no SSID set.

I had the same problem as you and noticed the SSID not being set on my own machine. I set this using iwconfig wlan0 essid "xxxxxxxxx" and it immediately popped into action.

The SSID is set in the interfaces file but obviously it's not being read or retained. I now have to figure out how to configure it so that it 'sticks'. :-(