I posted this question on the sane-devel list a few weeks ago and Johannes Meixner was so kind as to point me to a possible solution, but that didn't work. Since I'm having this problem only with openSUSE machines, I now think this is actually the right list to ask. I have a multifunction printer Canon MF746Cx. I also have several machines, relevant are one bare-metal Ubuntu 22.04, one VM Kali 2024, one VM Debian 12, both running under openSUSE Leap 15.5 with KVM, the bare openSUSE Leap 15.5 and one bare-metal Tumbleweed. Like said, on all three Debian-based machines, scanning just works out of the box. On both openSUSE machines, it doesn't. I have installed for Leap and TW the sane-airscan package from https://software.opensuse.org/search?baseproject=ALL&q=airscan as suggested by Johannes Meixner in the other mailing list. One thing I have noticed is that in both openSUSE machines "airscan-discover -d" only "tries" the network address of the machine itself: it seems not to "go out of the machine", whereas in the Debian-based machines it scans the entire network. Could it be a firewall/apparmour/selinux problem? Any suggestion would be most appreciated. Thank you.