I hate how #ifup blocks #networkmanager from using device and sometimes not establishing connection anyway #linux #debian
@3d7e45da You can change that. In /etc/network/interfaces just have the loopback, nothing else. In NetworkManager.conf remove the ifupdown plugin and use only NM's native keyfiles. Reboot. Don't use the "ifup/ifdown" commands anymore, use proper "nmcli con up/down".