If you have a static IP I'd recommend setting it up in /etc/netplan and set dhcp4 to false, then netplan apply instead of hacking your way around. Ubuntu since at least 18.04 uses netplan for network configuration.I've looked at all the router distros and they seem rather limited in scope. Ok, so I want to make a router using Ubuntu Server 18.04 ( already have the hardware and it all works, I have IPfire currently on it).