Configure Debian to connect WiFi

Configured Debian on a laptop to connect some wireless LANs.

First, the driver ipw2200 is needed. Debian package is firmware-ipw2x00. See ipw2200 - Debian Wiki. wpa_supplicant can be installed by Debian package wpasupplicant. See WiFi/HowToUse - Debian Wiki. To switch between some wireless LANs, install ifscheme.

My /etc/network/interfaces contains the followings.

auto eth2
mapping eth2
        script ifscheme-mapping

iface eth2-a inet dhcp
        wpa-ap-scan 2
        wpa-scan-ssid 1
        wpa-ssid xxxxx
        wpa-psk xxxxx
        wpa-key-mgmt WPA-PSK
        wpa-proto WPA
        wpa-pairwise TKIP
        wpa-group TKIP

iface eth2-b inet dhcp
        wpa-ap-scan 2
        wpa-scan-ssid 1
        wpa-ssid xxxxx
        wpa-psk xxxxx
        wpa-key-mgmt WPA-PSK
        wpa-proto WPA
        wpa-pairwise TKIP
        wpa-group TKIP

Parameters ap-scan and scan-ssid were set in order to connect hidden ssids according to /usr/share/doc/wpasupplicant/README.modes. key-mgmt, proto, pairwise and group were set to connet WPA-PSK/TKIP according to /usr/share/doc/wpasupplicant/examples/wpa-psk-tkip.conf.

To switch wireless LAN, issue a command like ifscheme eth2-a as root. By putting foo ALL=NOPASSWD: /sbin/ifscheme to sudoers, User foo can switch by issuing sudo /sbin/ifscheme eth2-b without password.