WiFi
Contents
Pre-requites
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Note: To configure Wi-Fi you need to install wireless tools first (done by default for APF27 / PPS / APF51) and of course to have a running Wi-Fi interface like: the one on APW extension board or PPS devt board or a USB to Wi-Fi adapter, with corresponding Linux drivers loaded. |
Common operations
List network interfaces supporting Wi-Fi
# iwconfig
lo no wireless extensions.
eth0 no wireless extensions.
sit0 no wireless extensions.
wmaster0 no wireless extensions.
wlan0 IEEE 802.11bg ESSID:""
Mode:Managed Frequency:2.412 GHz Access Point: Not-Associated
Tx-Power=0 dBm
Retry min limit:7 RTS thr:off Fragment thr=2352 B
Encryption key:off
Power Management:off
Link Quality:0/100 Signal level:112/146 Noise level:0/0
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
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Note: Here our Wi-Fi network interface is called wlan0. Depending on the number of your network interfaces or their model, this name could change. For example if using the Libertas drivers, the interface will be called eth1 (if eth0 is already used). In that case replace wlan0 with your interface name. |
Activate the WLAN interface
# ifconfig wlan0 up
Show all Access Points (AP) available for your APF (here with wlan0 interface)
# iwlist wlan0 scan
wlan0 Scan completed :
Cell 01 - Address: XX:XX:XX:66:47:48
ESSID:"TOTO"
Mode:Master
Channel:1
Frequency:2.412 GHz (Channel 1)
Quality=88/100 Signal level:25/100
Encryption key:on
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
48 Mb/s; 54 Mb/s
Extra:tsf=00000009d398fec8
Extra: Last beacon: 1390ms ago
...
Connect to an unencrypted AP
# iwconfig wlan0 essid AP_NAME
- Check it:
# iwconfig wlan0
Get an IP address
# udhcpc -i wlan0
Encryption settings
When configuring Wi-Fi cryptography, only WEP can be setup easily from a terminal with single commands. If you want to configure your interface for WPA/WPA2, install and configure wpa_supplicant.
WEP configuration
This example is given for a Wi-Fi Access Point named armadeus, the encoding key used here is not recommended, of course ;) :
# iwconfig wlan0 essid armadeus # iwconfig wlan0 key 12345678901234567890 # ifconfig wlan0 up (if interface is not already up) ADDRCONF(NETDEV_UP): wlan0: link is not ready # ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
Now, the Wi-Fi adapter is ready and attached :
# iwconfig
lo no wireless extensions.
eth0 no wireless extensions.
sit0 no wireless extensions.
wmaster0 no wireless extensions.
wlan0 IEEE 802.11bg ESSID:"armadeus"
Mode:Managed Frequency:2.437 GHz Access Point: 00:1B:2F:E7:E4:08
Bit Rate=2 Mb/s Tx-Power=7 dBm
Retry min limit:7 RTS thr:off Fragment thr=2352 B
Encryption key:XXXXXXXXXXXXXXXXXXXXXXXXXX Security mode:restricted
Power Management:off
Link Quality:0/100 Signal level:73/146 Noise level:0/0
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
Accessing outside world
We can manually configure the network to access Internet via the Wi-Fi interface instead of the Ethernet one:
# ifconfig eth0 down # ifconfig wlan0 192.168.0.212 # route add default gw 192.168.0.1 dev wlan0
And configure the nameserver in /etc/resolv.conf
domain dev.null nameserver 192.168.0.207 ~ ~ ~
If you have a DHCP server on your network, you can also use it and previous steps (route+resolv.conf) will be done automatically:
# udhcpc -i wlan0
We can now ping the best website in the world :
# ping www.armadeus.org PING www.armadeus.org (213.186.33.5): 56 data bytes 64 bytes from 213.186.33.5: seq=0 ttl=122 time=66.735 ms 64 bytes from 213.186.33.5: seq=1 ttl=122 time=50.392 ms ^C --- www.armadeus.org ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 50.392/58.563/66.735 ms
Surf on the net
To surf on the web, you can use (for example) links software :
# links www.armadeus.org
It's an ASCII internet browser. For more informations about Links.
