help: Disable assignment of IPv6 addresses on all interfaces

create:
	sudo sh -c "echo options ipv6 disable_ipv6=1 > \
	    /etc/modprobe.d/vyatta_disable_ipv6.conf"
	echo "This change will take affect when the system is rebooted."

delete:
	sudo sh -c "rm -f /etc/modprobe.d/vyatta_disable_ipv6.conf"
	echo "This change will take affect when the system is rebooted."