sudo apt-get install --reinstall linux-headers-$(uname -r) linux-headers-generic build-essential dkms
wget http://media.cdn.ubuntu-de.org/forum/attachments/45/14/3005217-r8168-dkms-8.038.00.tar.gz
sudo tar xvf 3005217-r8168-dkms-8.038.00.tar.gz -C /usr/src
sudo dkms add -m r8168-dkms -v 8.038.00
sudo dkms build -m r8168-dkms -v 8.038.00
sudo dkms install -m r8168-dkms -v 8.038.00
sudo depmod -a
sudo update-initramfs -u 
echo "blacklist r8169" | sudo tee -a /etc/modprobe.d/blacklist.conf

e dopo 

sudo mii-tool -F 100baseTx-FD eth0