Undo the settings of pppoeconf command
"pppoeconf" sets up dialup networks on linux/ connect to internet without connecting via network manager. But thats done, it sets up few files to always do that. To undo this on ubuntu, follow these steps : 1) Edit nm-system-settings.conf vim /etc/NetworkManager/nm-system-settings.conf You have to write managed=true under [ifupdown] 4) Edit interfaces vim /etc/network/interfaces This file must look like this: auto lo iface lo inet loopback auto eth0 iface eth0 dhcp 5) Restart your computer reboot 6) Finished.