Camille Terol

You actually don't need to. Just make sure your OpenVPN server listens on the external interface.

Well, you don't really need the internal. What you're trying to achieve is having an OpenVPN server that listens on the external interface, and that gives you access to Internet thourg the same interface. The internal interface is probably in case you want to interconnect several VMs on Google Cloud.

Can you post a screenshot of what you're seeing? Maybe I could help.

Usually, on a VM like the one provided by Google, you get an external IP address, which means that you won't need to configure port forwarding and NAT in order to access to your OpenVPN server. The script that razibhasan mentioned looks good. Maybe you can install a VM with CentOS or Debian, and use this script to setup your VPN server on it.

According to the documentation of the device you're talking about : So when you're using USB tethering, the device should not run out of battery. If it is, like it was mentioned before, either your laptop is not providing enough juice, or your unit is faulty. You can find the documentation i quoted here http://www.downloads.netgear.com/files/aircard/AC815S_ATT/AC815S_ATT_UM.pdf

Well you have plenty of options : You could either choose to run a Virtual Machine Instance on the Google Cloud Platform (GCP) : From there you could choose to go with the public image with your distro of choice (https://cloud.google.com/compute/docs/images#os-compute-support) and install the appropriate open-vpn package (You'll find great tutorials if you google the name of your distro + open vpn) You could also choose to, for example go with a custom Image and run pfSense on your VM. pfSense is a distribution that can be used as a firewall, that is based on FreeBSD (for a solid foundation), and comes bundled with several options for running VPN servers, and a nice Web GUI, but is, IMHO a little overkill for your project. Or you could try and find an appropriate container image, containing an installation of open-vpn server, and running it as a container on GCP. Whatever you decide, please first read on and make some research about these two options (a google search with "running a vm on gcp", "install open-vpn server on debian" will go a long way), and ask us question! We'll be happy to help! PS: You could also choose to use a VPN service, which will require almost no setup, or another Cloud Provider. In any case, best of luck in your project!

Can we get another picture? I'm not quite sure what you're asking help for.