Below is how I setup Wireless in OEL 5.4:
Depending on your Wireless hardware you may have to install appropriate drivers. The following link may have the information you need:
http://wiki.centos.org/HowTos/Laptops/Wireless
You need to know what type of encryption you are using on the wireless network. The recommended WPA encyrption is not included in the general network adminstation tools. You will find better support for Wireless in Linux desktop systems, e.g. Ubuntu. There are 2 ways to configure Wifi in RHEL, CentOS or OEL, and the most "user friendly" is probably to use Network Manager (gnome), which you can install using:
yum install NetworkManager
Then you type:
service NetworkManager start
and to have it automatically start at next reboot:
chkconfig NetworkManager on
This will show up a new icon in the top right hand side of the menubar. It should be obvious how to connect to your wireless network when you cllick on it.
You can disable the network devices using the standard control panel, as well as the wpa_supplicant services at boot time, since NetworkManager will do the tasks. To disable type "chkconfig wpa_supplicant off", but this is not necessary.
Note: When you restart the compouter, the Wireless connection will be automatically established as soon as you log into the system.
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It gets a bit more compolex to automatically establish a Wifi connection at system startup (without login):
Provided that your wirless network card is detected at system startup or after you have installed the drivers, you should see the interface typing
ifconfig -a
For instance 'eth1', you will than scan the network to find out the ssid for you wirless network typing:
ifconfig eth1 up
iwlist eth1 scan
This will also confirm that your wirless card is working. Next, create a password key using:
wpa_passphrase myssid thisismysecretpassword
This will create a key that you need to type into:
/etc/wpa_supplicant/wpa_supplicant.conf
For instance:
ctrl_interface=/var/run/wpa_supplicant
network= {
ssid="myssid"
scan_ssid=1
proto=WPA RSN
key_mgmt=WPA-PSK
pairwise=CCMP TKIP
group=CCMP TKIP
psk=thekeyIgeneratedearlier
}
The next steps you can type manually or put into /etc/rc.local, which is supposed to be the last file read by init during bootup or run level change. For instance:
pkill dhclient
pkill wpa_supplicant
ifconfig eth1 down
ifconfig eth1 up
wpa_supplicant -Bw - Dwext -ieth1 -c/etc/wpa_supplicant/wpa_supplicant.conf
dhclient eth1
Best of luck,
Markus