Commands to setup NAT:
sysctl net.ipv4.ip_forward=1
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE
iptables -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -i eth0 -o eth1 -j ACCEPT
...
https://www.youtube.com/watch?v=B0XUeC9f3zQ