I’m afraid I can’t find any “Preferences” option in the Boxes window. When I launch a VM the window gets a “three dots” button from which I can open a Preferences dialog, but that doesn’t have any options regarding the network interface.
Anyway, the reverse ssh tunnel method works for me.
I even automated it by installing autossh
sudo zypper addrepo https://download.opensuse.org/repositories/security/16.0/security.repo
sudo zypper refresh
sudo zypper install autossh
and adding
@reboot kls autossh -M 0 -f -N -R 2222:localhost:22 kls@eagle
to /etc/crontab on the VM. Also did
ssh-keygen
ssh-copy-id kls@eagle
on the VM to make autossh work without password.
Note that “kls” is my user name and “eagle” is the name of the machine from which I want to ssh to the VM.