I work support and mainly work with PCs so my mac experience is limited. Right now one of the mac laptops we support is not utilizing the wifi at the user login screen and displaying "Network accounts are unavailable." I can login with the local admin and the wifi automatically connects as it should then, but I can't seem to jiggle anything loose to restore the wifi connection at login screen. I would appreciate any help or advice on how to restore this functionality as all of the laptop users need to be connected to the wifi for their domain accounts to be granted access on the laptop.
I presume you mean this error message:
I have had this problem in the past, due to an incorrectly configured DNS on the local machine. If it's only the Wi-Fi that the network accounts are unavailable on (as it was for me), try changing the DNS to point to the correct server for Wi-Fi connections.
networksetup -setdnsservers Wi-Fi <server-ip>
What kind of authentication does the Wi-Fi network use? If it's just password-based then the password should be stored in the System Keychain (check within Keychain Access) rather than the login keychain. Move it if it's not.
If it's certificate-based, you'll need to set up a login window (or system) profile to configure it: http://www.afp548.com/2013/03/07/another-way-to-enable-wi-fi-at-login-window-with-profiles/
You need to bind the domain to the exact domain url
First I want to thank everyone for trying to help me in comments and in answers.
Being used to windows I assumed that like windows I could bind the domain to either the exact domain url "example.com" or the domain name "EXAMPLE". While both would bind successfully for the laptop, the difference was what was causing my wi-fi login issues. By binding it to "example.com" I was able to easily login with any domain credentials.