When I boot my Ubuntu 18.04 box (this is an old machine that's been through several upgrades) after moving apartments and changing the local subnet from 192.168.1.0 to 192.168.0.0, my networking is broken.
$ sudo route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.1.1 0.0.0.0 UG 202 0 0 eth0 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 202 0 0 eth0
However, I can't for the life of me figure out what's adding the incorrect configuration. I can just apply the netplan I have and everything is correct.
$ sudo netplan apply $ sudo route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
I've actually disabled DHCPD, NetworkManager, and there is no interfaces file in /etc/network. So what's trying to (re?)configure eth0? How can I clean this up so that I don't have to manually fix the network on a reboot?