It is easy enough, but it is fragile. If NAT is misconfigured, your network stops working. If firewall is misconfigured (or e.g. your network topology has chang

It is easy enough, but it is fragile. If NAT is misconfigured, your network stops working. If firewall is misconfigured (or e.g. your network topology has changed and you forgot to update the firewall configuration), the network works, but it is exposed to the elements and security goes away. We have enough security problems with IoT even in mostly IPv4 world; with massive IPv6 deployment, it wilk be a total nightmare.