It is almost inevitable that at some point in time, some of the devices in your IoT device fleet will malfunction in some way or another. You need a plan to address this. Port forwarding as a way to remote access a device can create a security risk if not performed correctly. Leveraging Raspberry Pi port forwarding can expose a network port on your network to the public internet. This is a known security vulnerability and can create risk. Port forwarding, alternatively described as port mapping, is often used to access a Raspberry Pi which is on a local network behind a NAT router so that it is separated from the public Internet. You then need router configuration knowledge to be able to manually open up ports so that you would be able to access a web server running on the Raspberry Pi via a specific port in it such as Port 22 for a SSH connection of 80.
This is a companion discussion topic for the original entry at https://mender.io/blog/remote-inspect-your-device-without-using-traditional-raspberry-pi-port-forwarding