Oh my fault, 99-default.link is available, I checked the wrong folder. The file is containing some text, saying that the machine is most likely a virtualized guest.
> Am 27.07.2017 um 19:28 schrieb Michael Biebl <bi...@debian.org>: > > Am 27.07.2017 um 18:55 schrieb debian-li...@patschie.de: > >>> Am 27.07.2017 um 18:25 schrieb Michael Biebl <bi...@debian.org>: >>> lsinitramfs /boot/initrd.img-$(uname -r) | grep 99-default.link >>> lib/systemd/network/99-default.link >> Missing > > Odd. Do you have that file on the host system? > Can you check with debsums -as udev systemd. > > /usr/share/initramfs-tools/hooks/udev should copy that link file into > the initramfs. > > Do you by chance have any custom initramfs hooks in > /etc/initramfs-tools/hooks which override the udev hook? > >