# /etc/sysctl.conf, will be added on next reboot
net.ipv4.ip_forward = 1
net.ipv6.ip_forward = 1

# enable routing NOW, then load netfilter modules
echo "1" > /proc/sys/net/ipv4/ip_forward
echo "2" > /proc/sys/net/ipv6/ip_forward
modprobe ip_tables
modprobe ip_conntrack

# add a nat-entry masquerading source addresses to eth1 interface addresses
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE