Nach einer frischen Installation von Kubuntu 12.04 wurde uns keine aktive Internetverbindung angezeigt, obwohl vorhanden!
cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto eth0
iface eth0 inet dhcp
sudo nano /etc/network/interfaces
sudo sed -ri "s/^(auto eth0)/# \1/" /etc/network/interfaces
sudo sed -ri "s/^(iface eth0 inet dhcp)/# \1/" /etc/network/interfaces
sudo service network-manager restart
syve 