Wireless

Last update: 23 july 2016.

In order to have a wireless connection available under GLLFSC, I recommend you follow the following steps.

Hardware

First, you have to find the model of your wireless card:

lspci | grep -i wireless

For Lemote Yeeloong 8133, the result of the previous command is:

04:00.0 Network controller: Atheros Communications Inc. AR9285 \
Wireless Network Adapter (PCI-Express) (rev 01)

Driver

To make your wireless card work, you need to compile the corresponding driver with the kernel Linux, built-in or as a module. To know which driver of the kernel corresponds to your wireless card, I encourage you to browse http://h-node.org/wifi/catalogue/en. My search with AR9285 informs me that this card uses the free driver ath9k.

Interface

In order to know which network interfaces does support wireless, you can use the following command from wireless_tools:

iwconfig

In general, the network interface that has wireless extensions is named wlan0. You may need to activate this interface:

ifconfig wlan0 up

ESSID

In order to connect to a wireless access point, you need to know its ESSID. To do this, you can use the iwlist command from wireless_tools:

iwlist wlan0 scan | less -c

Access-point Association

To associate the interface with an access-point, you need to know if it will encrypt your connection.

No encryption

If you decide not to use encryption for your wireless connection, to associate with the MYESSID access-point:

iwconfig wlan0 essid "MYESSID"

Encrytion

If you decide to use encryption, you should install wpa_supplicant. If you want to use GnuTLS as the library on which you build wpa_supplicant, you will need to install libgpg-error, libgcrypt and nettle first. Otherwise, you can install OpenSSL. Once wpa_supplicant has been installed, you can associate with an MYESSID access-point supporting encryption with:

wpa_supplicant -B -Dwext -iwlan0 -c/etc/wpa_supplicant.conf

The file /etc/wpa_supplicant.conf contains the configuration you want.

IP attribution

If you have chosen to use DHCPCD, dynamic IP attribution to wlan0 is done with:

dhcpcd wlan0

Problems and solutions

You may encounter errors while trying to set a wireless connection to the internet. Here are some I encountered and for which I found a solution.

# ifconfig wlan0 up
ifconfig: SIOCGIFFLAGS failed: No such device
# ifconfig wlan0
ifconfig: error interface 'wlan0' does not exist

Those 2 error messages indicate that interface named wlan0 does not exist. In my case, this happened when the driver ath9k was not available because I did not install modules after having built the kernel. Because ath9k was built as a module in my configuration, this problem disappeared after I installed the kernel's modules.

# ifconfig wlan0 up
ifconfig: SIOCGIFFLAGS failed: Operation not possible due to RF-kill

In my case, this error appeared because hardware prevented the activation of the wireless interface wlan0. On Lemote Yeeloong 8133, press simultaneously keys FN and F1 in order to allow the activation of the wireless interface. You may also do echo 0 > /sys/class/rfkill/rfkill0/hard as root. Then issuing ifconfig wlan0 up again should work as intended.