Then, a miracle happens.

Now, all thats left is the one magic line that does the actual act of masquerading packets. Add this line to the script: iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
This rule uses the “nat” table, and the special “POSTROUTING” chain, which isn't used too much outside of IP Masquerading. It also uses the MASQUERADE target, which virtually nothing else uses.
Now see, that was easy, right?
Much easier than herding llamas, I promise you. Those things can spit.

Now, all thats left is the one magic line that does the actual act of masquerading packets. Add this line to the script: iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE