Notes Before Beginning
To connect to GlobalProtect VPN before logon, it must be properly configured on your device. If you can not follow this guide, it is likely not configured and you'll need to submit and Atlas ticket to request configuration. You must be connected to the Internet before attempting VPN connection. This procedure only works on first boot; if you are logged in and log back out or lock the machine, you will not have the option to VPN from the logon screen until next reboot.
Procedure
Click on the VPN Networks Icon
This icon can be found in the bottom right of your logon screen after a reboot or power on. The icon is not visible if your screen is locked or someone has already logged in once without rebooting.

Choose the GlobalProtect Network
I GlobalProtect network is noted by the grey planet icon in the list of VPN networks in the bottom left. You may have more than one VPN network available, as shown below in the example. Once you choose a VPN network, it will immediately attempt to connect.

DUO Authenticate
Upon attempting to connect you will be immediately prompted to DUO (UTD's multifactor authentication) authenticate with your UTD NetID and password.

Successful Connection
Once DUO authentication has successfully completed your VPN icon will change from connecting to connected.

Logon
Upon successful connection, you can click back and logon to the machine with your UTD NetID and Password.

Final Notes
You do not need to do this every time you log on to the machine. This procedure is for first-time logon of a new machine off-site. Once you have successfully logged on to the computer with your NetID once, your credentials should be cached, and you do not need to VPN in or even be connected to the Internet. If your NetID password changes, this method can be used to cache your new credentials.