connman
From thelinuxwiki
connman sucks!
config files
/etc/connman/main.conf
/var/lib/connman/settings
individual connection configs...
/var/lib/connman/<connection_dir>/settings
dastardly default routes addition in /var/log/syslog (breaks routing)...
Jun 6 22:47:44 localhost connmand[781]: enp5s0 {add} route 0.0.0.0 gw 0.0.0.0 scope 253 <LINK>
interface blacklisting
NetworkInterfaceBlacklist = enp5s0