Ubuntu: wireless network with wpa encryption

Before I got the great tip described above I used the following method. This one is less handy if you're roaming around with your laptop from access point to access point:

1) Open a terminal window and type:
Code:

# wpa_passphrase your_ssid your_psk

Note: your_ssid is the name of your wireless network (a.k.a. SSID) and your_psk is the password you want to use to protect your network. (Look below for an example).

2) Now copy the psk string you got as output.

3) Type:
Code:

# sudo gedit /etc/wpa_supplicant.conf

Then paste this as follow:
Code:

ctrl_interface=/var/run/wpa_supplicant #ap_scan=2 network={        ssid="your_ssid"        scan_ssid=1        proto=WPA RSN        key_mgmt=WPA-PSK        pairwise=CCMP TKIP        group=CCMP TKIP        psk=your_psk }

Note: your_psk is the psk string you got from step 1.

Here is an example:
Code:

luca@laptop1:~$ wpa_passphrase mywlan thisisthepassword network={         ssid="mywlan"         #psk="thisisthepassword"         psk=b22ec921c254c73f99b31b76ff876692ecde36839a1f2d92150829e6afcb5515 }

The red string is what you have to paste into /etc/wpa_supplicant.conf as your_psk (without quotes obviously). So you'll have something like this:
Code:

ctrl_interface=/var/run/wpa_supplicant #ap_scan=2 network={        ssid="mywlan"        scan_ssid=1        proto=WPA RSN        key_mgmt=WPA-PSK        pairwise=CCMP TKIP        group=CCMP TKIP        psk=b22ec921c254c73f99b31b76ff876692ecde36839a1f2d92150829e6afcb5515 }

4) Save the file and close Gedit.

5) Now we have to make wpa_supplicant load when system boots, so go back to the terminal window and type:
Code:

# sudo gedit /etc/network/interface

6) Add the following lines in the part regarding your wireless card, as in the example below:
Code:

pre-up wpa_supplicant -Bw -Dwext -ieth0 -c/etc/wpa_supplicant.conf post-down killall -q wpa_supplicant

Note: "eth0" is your wireless device and "wext" is the driver; this is a kind of generic driver, so it should work with most wireless cards. If it doesn't, please try another driver, such as hostap, ndiswrapper, etc.
Here is an example:
Code:

iface eth0 inet static address 192.168.1.15 netmask 255.255.255.0 wireless-essid my_essid gateway 192.168.1.1 pre-up wpa_supplicant -Bw -Dwext -ieth0 -c/etc/wpa_supplicant.conf post-down killall -q wpa_supplicant

7) Now run wpa_supplicant:
Code:

sudo wpa_supplicant -Bw -Dwext -i eth0 -c/etc/wpa_supplicant.conf

You should be online!

Many thanks to the Ubuntuforum

Fedora7 stuff:
http://forums.fedoraforum.org/showthread.php?t=156435&page=2&pp=15
http://forums.fedoraforum.org/showthread.php?t=161881