Body of Knowledge

After trying the gnome network configuration tool with little success, I tried the hardcore version, changing by hand the /etc/network/interfaces file again with little success.

First search for your AP:

$ iwlist eth1 scanning

If you have a working wireless network adapter (eth1) and your AP in range, your configuration file should look something like this:

auto eth1
iface eth1 inet dhcp
wpa-driver wext
wpa-ssid SSID
wpa-ap-scan 1
wpa-proto WPA
wpa-pairwise TKIP
wpa-group TKIP
wpa-key-mgmt WPA-PSK
wpa-psk XXXXXXXXXXXXXXXXXXXXf4b3cff05d8ebf483435050268bxxxxxxxxxx

Your key for wpa-psk can be generated using:

 sudo wpa_passphrase SSID "passphrase"

So what can actually make you nuts is that if you used an hidden SSID, it will not work until you make the SSID visible once… and then you can go back into being hidden again.

Another way is to use the command iwconfig:

sudo iwconfig eth1 essid "hidden_ssid"