This is how I connected to the Penn. State wireless network (2.0) with GNU/Linux and wpa_supplicant. Here is the network information from PSU:

SSID: psu
Security: WPA2-Enterprise
Encryption: AES
Authentication Type: EAP-TTLS
Authentication Protocol: PAP
Certificate Authority: Thawte Premium Server CA

The following configuration block needs to be entered into /etc/wpa_supplicant.conf:

network={
    ssid="psu"
    identity="your_access_id_here"
    password="your_password_here"
    key_mgmt=WPA-EAP
    eap=TTLS
    phase2="auth=PAP"
    ca_cert="/etc/ssl/certs/Thawte_Premium_Server_CA.pem"
}

Check that your wireless card is up with `ifconfig` and that you are in range of an access point with `iwlist scan`. You can now connect using wpa_supplicant and dhcpcd. Change the following line to use your wireless driver and interface.

wpa_supplicant -B -D wext -i wlan0 -c /etc/wpa_supplicant.conf
dhcpcd wlan0