Bloging about Devops things and simple copy+paste steps
Tested on 26 November 2020
To configure Droplets as internet gateways Follow everything in Digital Ocean Blog.
The above configuration will not work if you want to Turn Off the public network interface eth0, because the blog show how to send the traffic over eth0 and not private network interface eth1. To send internet traffic over ‘eth1’ use the following command in your backend droplet instead of the one in the Digital Ocean Blog.
ip route add 169.254.169.254 via <your-gateway-private-IP> dev eth1