The wired internet connection by default is configured properly in Ubuntu installation. We can directly dial-up via
sudo pppoeconf, or connect to a cable which already on internet. But sometimes wired connection stop working because of kernel upgraded, installed a special program, or even something to do with wireless.
Here’s a solution that fixed my wired problem while I was trying access internet via a router(that has already access to internet) and before I directly pppoe dial-up. It also works for kernel upgrade reason, but not sure for every situation.
1.) First run
and the problem’s always that no assigned ip from cable on eth0. Use
sudo dhclient eth0
and it works again, but it stops working after reboot.
2.) Edit the file “/etc/network/interfaces” and change it looks like this:
# The loopback network interface
iface lo inet loopback
# The primary network interface
iface eth0 inet dhcp
BTW: if you have the wireless connection up, that might interfere with wired connection, you can try wicd-network-manager(available in Ubuntu Software Center) to configure the wireless connection.