Simon McVittie:
If sshd uses (or can be made to use) IP_FREEBIND to remove the
> potential dependency on bringing up network interfaces, then > /lib/systemd/system/ssh.service could have DefaultDependencies=no, > RequiresMountsFor=/usr /lib /etc, and drop its dependency on > network.target.Altering sshd is altering the wrong thing. This is what FreeBind=true in a socket unit and the --bind-to-any option in nosh's tcp-socket-listen program are for.