Prerequisite
To be able to use VPN to access the GFZ network you have to activate VPN on the 'Passwords & Services' site on the intranet.
Installation
Go to asa.gfz-potsdam.de.
Select "GFZ employees" and click Login.
In the new window, log in with your GFZ username and domain password.
Then enter the code from your 2-factor authentication device.