Ok, issue solved by trial and error.
I did three things after which the network configures and the Pimcore instance is accessible:
- converted the vmdk Disk to a VMWare Infrastructure virtual machine using the VMWare Standalone Converter (6.2)
- changed the setting for the OS from "other linux" to "Debian/GNU Linux 9" in the VM settings
- activated an DCHP server within the network to allow the VM to retrieve an IP address
Maybe the DHCP alone would have done it.