For example, when a wireless networking device is first recognized and
initialized for use, the driver most likely reports a new device, like so:
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zd1211rw 5-4:1.0: firmware version 4725
zd1211rw 5-4:1.0: zd1211b chip 050d:705c v4810 \
high 00-17-3f AL2230_RF pa0 G—nszd1211rw 5-4:1.0: eth2usbcore: registered new interface driver zd1211rwThis output (from the dmesg command) shows that the eth2 device has
been reported. If DHCP is in use, the device should automatically join the
nearest wireless subnet and be automatically assigned an IP address. If not,
the next step is to use a wireless tool such as iwconfig to set various
parameters of the wireless device. The iwconfig command, along with the
device name (eth2 in this example), shows the status:
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matthew@seymour:~$ iwconfig eth2
eth2 IEEE 802.11b/g ESSID:"SKY35120" Nickname:"zd1211"
Mode:Managed Frequency:2.462 GHz \
Access Point: 00:18:4D:06:8E:2A
Bit Rate=24 Mb/s
Encryption key:0EFD-C1AF-5C8D-B2C6-7A89-3790-07A7-AC64-
0AB5\
-C36E-D1E9-A230-1DB9-D227-2EB6-D6C8 Security mode:open
Link Quality=100/100 Signal level=82/100
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
This example shows a 24Mbps connection to a network named SKY35120.
To change a parameter, such as the transmission rate, use a command-line
option with the iwconfig command like this:
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matthew@seymour:~$ sudo iwconfig eth2 rate 11M
Other options supported by the iwconfig command include essid, to set
the NIC to connect to a specific network by name; mode, to enable the NIC
to automatically retrieve settings from an access point or connect to another
wireless host; and freq, to set a frequency to use for communication.
Additional options include channel, frag, enc (for encryption), power,
and txpower. Details and examples of these options are in the iwconfig
man page.