Ok, we can take both but needs to be in a specific order. So, we have two ethernet interfaces, A and B. And both are defined in /etc/systemd/network/ to use dhcp. How to guarantee that the crap provided by dhcp to A (dns, gateway, ntp) is the default? To use an example, /etc/resolv.conf should end up like nameserver IP.for.A.DNS nameserver IP.for.B.DNS domain A.domain.com Now, this must be done using only systemd stuff