There is currently (11:00 a.m.) a disruption in the ZUV VPN. The disruption means that dial-in to the ZUV VPN is failing.
Due to the switch to a new server and the associated delay of about an hour, the VPN will presumably be accessible again from 12:00 noon.
Update (5:30 p.m.):
The malfunction of the ZUV VPN has been resolved.