Managing to import Mininet VM image into VirtualBox

The network emulator Mininet offers VM images for download, which can be imported, e.g., into VirtualBox.

A common problem seems to be that the delivered ovf file (in my case mininet-2.1.0-130919-ubuntu-13.04-server-amd64.ovf) causes an exception when VirtualBox tries to import it: VBOX_E_NOT_SUPPORTED (0x80BB0009).

Even setting the OS manually to Ubuntu (64bit) did not help.

I finally found the solution in this post: You may also create a new virtual machine and select the contained VM disk image mininet-vm-x86_64.vmdk as hard disk.