How To Configure Wireless / WiFi Networking in Ubuntu via the Command Line (CLI)
There are a number of tutorials available on-line for sorting out WiFi in Ubuntu via the CLI, but most of them seem quite outdated, so I decided to do my own.I did this on a minimal install of Ubuntu Lucid, so it is as up-to-date as possible. The PC I was using has no Windows Manager of Graphical Display Manager, just the good old terminal so all this is done via the CLI only. I did this using a USB WiFI dongle, but it should be the same whether you use an internal card or a USB card.
First, you need to install the relevant software. You need to have a wired connection at this point, otherwise this wont work.
sudo apt-get install wireless-tools wpasupplicantIf you are connecting to an open network, you wont need wpasupplicant. Next, you need to “bring up” (essentially this means activate) your WiFi interface. So, issue:
sudo ifconfig wlan0 upNext, to make sure your wireless device is working as it should issue:
iwconfigand then
sudo iwlist scanThis should show you some wireless networks as proof that the WiFi device is working, if something goes wrong here, then there is a problem with your device or driver and you need to get googling.
If you are accessing a secured network and you really should be, you need to access the correct version of your WiFi key. To get your key, issue this command:
wpa_passphrase YOURSSID YOURWIFIPASSWORD This will result in something that looks like this:
network={
ssid="YOURSSID"
#psk="YOURWIFIPASSWORD"
psk=fe727aa8b64ac9b3f54c72432da14faed933ea511ecab1 5bbc6c52e7522f709a
} You need to make a note of the long phrase after psk= (NOT #psk=) as this your WiFi password in hex format.
Next, you need to edit your interfaces file, so issue:
sudo nano /etc/network/interfacesAt the end of this file, you need to add your WiFi configuration. Here are the options you can add.
auto wlan0 #change this to the name of your WiFi interface
iface wlan0 inet dhcp #this is normally fine, if you want a static IP address replace “dhcp” with “static”
netmask 255.255.255.0 #change this as appropriate for your network, this value is usually right
gateway 192.168.1.1 #change this as appropriate for your network
address 192.168.1.100 #only needed for a static IP address
dns-nameservers 192.168.1.1 #only needed for a static IP address
wpa-driver wext #you shouldn’t need to change this
wpa-ssid YOURSSID #just type the name of your SSID here
wpa-ap-scan 1 #if the name of your SSID is hidden usually, type 2 instead of 1
wpa-proto WPA #if you use WPA1 type WPA, if you use WPA2 type RSN
wpa-pairwise CCMP #if you use AES type CCMP, if you use TKIP type TKIP
wpa-group CCMP #if you use AES type CCMP, if you use TKIP type TKIP
wpa-key-mgmt WPA-PSK #usually WPA-PSK (if you share a key) but sometimes WPA-EAP (for enterprises)
wpa-psk YOURHEXKEYFROMABOVE #the hex key that you generated earlier
Thus, since I am using a WiFi card that is identified as wlan0 and am connecting to a WPA1 AES encrypted network called MYPLACE that isn’t hidden without a static IP address, this is what I added:
auto wlan0
iface wlan0 inet dhcp
netmask 255.255.255.0
gateway 192.168.1.1
wpa-driver wext
wpa-ssid MYPLACE
wpa-ap-scan 1
wpa-proto WPA
wpa-pairwise CCMP
wpa-group CCMP
wpa-key-mgmt WPA-PSK
wpa-psk 71c81a844973ae7bb1243141e5caa7b6bb0e2d7eetcetcetcFinally, comment out the top section so it looks like this:
#auto eth0
#iface eth0 inet dhcpThis stops your wired network from working. This helps to ensure there are no conflicts. Remember, if you want your wired network to work again, remove these two comments (the #).
Finally, save the file by pressing CTRL and X and then pressing Y to save to the file. Now, reboot and your network should come up. Yay!
Some people have found that this doesn’t always work, so the next thing to do is to edit the configuration file for the wpasupplicant program. Do this by issuing:
sudo nano /etc/wpa_supplicant.confBasically, you add pretty much the same information here as you did to the interfaces file, except without the wpa- part. So, my file looks like this:
ap_scan=1
ctrl_interface=/var/run/wpa_supplicant
network={
ssid="MYPLACE"
scan_ssid=0
psk=71c81a844973ae7bb1243141e5caa7b6bb0e2d7eetcetcetc
key_mgmt=WPA-PSK
proto=WPA
pairwise=CCMP
group=CCMP
}As far as I am aware, the options are the same. So, edit this file as necessary, make sure you add the ctrl_interface and network={ at the beginning and the } part at the end. Save it and try restarting again. If it still doesn’t work, then kick your PC, wish you had installed Windows 7 instead and go off and do some Googling. You’ll find the answer on the Ubuntu forums and you’ll be happy again.
Best of luck!
