This script is specially useful when you clone VMs, but can be used in any other kind of situation where you have problems with network cards, say, duplicated cards for X reason.

Try to run this script I wrote:

if [ $UID -ne 0 ] 
then
	echo "Sorry, you have to run this script as root"
else
	cat /etc/udev/rules.d/70-persistent-net.rules | grep PCI | cut -d' ' -f5 | cut -b 2-6 | uniq > /tmp/drivers
	for driver in $(cat /tmp/drivers); do
		rm -rf /etc/udev/rules.d/70-persistent-net.rules && echo "Removing 70-persistent-net.rules"
		rmmod $driver && echo "Removing $driver"
		modprobe $driver && echo "Loading $driver"
	done
	echo "Done."
	rm -rf /tmp/drivers
fi

Tested under Debian and Fedora, but should work fine on other distributions.

The code is also on my github