Wifi & Networking Configuration

Setting up Wifi under Gentoo involves several steps.

Get your driver working

• This depends on your wireless card. Usually it will require very recent releases of the Linux kernel, and additional drivers or programs.

• Once you have an interface working (eg iwconfig lists something) you can proceed to the next step.

Associating with an access point and Authentication

• Emerge wpa_supplicant.

• The configuration file used by wpa_supplicant under Gentoo is in /etc/wpa_supplicant/wpa_supplicant.conf. So edit your changes there. Sample below:

network={
        ssid="Arda"
        scan_ssid=1
        proto=WPA
        pairwise=CCMP TKIP
        psk="password_goes_here_56831"
        priority=2
}

• The pairwise option specifies the cryptographic algorithms used for authentication. CCMP also means AES.

• To basically test if authentication is working, launch wpa_supplicant with the -c and -i flags, supplying both a configuration file and an interface name. Example:

wpa_supplicant -ieth1 -c/etc/wpa_supplicant/wpa_supplicant.conf

Note that if you forget the -i or -c flag, wpa_supplicant will refuse to work.

• Once it is working, create a symlink in /etc/init.d:

ln -s net.lo net.eth1

where you replace eth1 with your interface name.

• Add some configuration options to /etc/conf.d/net. See for example this Gentoo documentation.

• Finally run /etc/init.d/net.eth1 start and if everything goes smoothly, you can add it to the default run level.

ipw3945 specific notes

• Be careful to add the daemon init script to the boot runlevel, not the default one. Else things won't work automatically after boot.

• Include ipw3945 in the list of modules to be autoloaded. However by default it will start the daemon as soon as it is loaded, and this does not work well on Gentoo (maybe because it should wait a little?). So modify the file /etc/modules.d/ipw3945d so that installing the module does not load the init script automatically. Then run (of course) update-modules. This way you can have a clean boot sequence without errors :)

A note on init scripts on Gentoo

In fact there is only a single init script, net.lo, for the loop back interface. Other scripts are simply added by making symbolic links to net.lo, changing the "lo" with the new interface name.