I’ve already written about configuring and using DLink wireless card with the help of RT61 driver. However, few readers like to know more about Wi-Fi Protected Access (WPA and WPA2) secure wireless configurations.

Step # 1: Configure Router / AP with WPA2 Security Mode

First you need to configure WPA2 security mode on the access point. All devices on your network must use the same security mode in order to communicate. Open router configuration by visiting default IP https://192.168.1.1/ and setup

• Security Mode: WPA2 Personal
• WPA2 Algorithm: You may choose from AES or TKIP+AES. Choose TKIP+AES if you have both WPA and WPA2 devices on your network.
• WPA2 Pre-Shared Key: Choose a unique key to authenticate with other devices on your network. The Pre-Shared Key must be between 8 and 63 characters in length. You can generate unique key by visiting this webpage. You can also use standard UNIX / Linux utilities to generates true random passwords (key) by using the /dev/random feature of Linux.
• Group Key Renewal: This settings determines how often your group key changes.

(Fig. 01: Configure WPA2 for your router / access point)

Step # 2: Configure RT61 Wireless Card

Open /etc/network/interfaces file and make changes as follows:
$ sudo vi /etc/network/interfaces
Output:

auto ra0
iface ra0 inet dhcp
pre-up iwconfig ra0 mode managed
pre-up ifconfig ra0 up
pre-up iwconfig ra0 essid nixcraft
pre-up iwpriv ra0 set AuthMode=WPA2PSK
pre-up iwpriv ra0 set WPAPSK='|zdUkK(!X)_'G!}@1|@OS/6RA#'+}eq8b&V@x1%OZyyDVV:Xwp8UmwLFNS^7=A+'
pre-up iwpriv ra0 set EncrypType=AES

Save and close the file. Make sure you replace device name (ra0), essid and WPAPSK with actual configuration parameters. Restart the networking:
$ sudo /etc/init.d/networking restart

Other simple security suggestion

1. Change the default admin password on the access point / router.
2. If possible turn off administration feature on the access point for wireless interface
3. Set up an access control list by Mac address of all devices you want to associate with the access point.

Please note that above instructions are only tested using RT61 driver under Ubuntu Linux. However, instructions should work with any other Linux distos and drivers with minor or minimum changes.

Suggested readings:

• man pages – iwpriv, interfaces, iwconfig
• Original RT61 configuration how to
• Wi-Fi Alliance’s WPA2 page