How to set up Wi-Fi from the command line

[Wolven]

This small guide is taken from Oithona's reply to this thread: Newbie need wireless help

This guide will show you how to configure Wi-Fi from the command line. It assumes you're using WEP encryption. It also assumes you're using DHCP. (Oithona, if you feel this guide needs editing, feel free to do so.)

1. Check your modem/router for the 10-byte WEP key, and for the essid

2. As root, in a terminal window, type the following commands:
(If you're not logged in as root, type 'su' without the quotes and hit <enter> in the terminal, and then type the root password when prompted)

Code:

iwconfig wlan0 essid <your access point essid>

Code:

iwconfig wlan0 channel auto

This will give you the following output:

Error for wireless request "Set Frequency" (8B04) :   
    SET failed on device wlan0; Invalid argument.

Code:

iwconfig wlan0 mode managed

Code:

iwconfig wlan0 key open <your key>

Code:

ifconfig wlan0 up

Code:

dhcpcd -d -t 8 wlan0

This should output:

dhcpcd: MAC address = XX:XX:XX:XX:XX:XX     <---your MAC address appears here
dhcpcd: your IP address = XXX.XXX.XXX.XXX   <---your IP address appears here

Code:

iwconfig

This command should show you information about the ready configured Wi-Fi device, something similar to this:

lo        no wireless extensions.

eth0      no wireless extensions.

wifi0     no wireless extensions.

wlan0     IEEE 802.11g  ESSID:"belkin54g"  Nickname:"wolvix"
          Mode:Managed  Frequency:2.462 GHz  Access Point: 00:30:F1:CF:8C:2D   
          Bit Rate:48 Mb/s   Tx-Power:17 dBm   Sensitivity=0/3
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:XXXX-XXXX-XX   Security mode:open
          Power Management:off
          Link Quality=53/94  Signal level=-46 dBm  Noise level=-99 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

If all went well your Wi-Fi device should be ready for use.