Connecting to SIM WAN networks using SSH and VPN

Installing and Using OpenWrt Network and Wireless Configuration
1

Hi there!

I have several OpenWRT IoT datalogger that I use to collect data from different buildings' metering systems.

On the router I succesfully managed to install a Python script that does all the data collection work and then sends all that data to a cloud based service.

I'd like to remotely connect to these devices, since as you may imagine they are widely spread apart and not meant to be updated or operated by manually plugging a USB cable to them.

The main problem is that these devices use normal IoT SIM cards which do not have public static IP, so it's impossibile (as far as I know) to SSH into them.

I read a lot about creating a VPN, but I don't know how to proceed from here and since I don't have enough experience with VPN in general, I wanted to ask for some guidance on the topic.

Is it possibile to create a VPN, maybe on an external server, from which I can connect to the different devices in SSH? The devices (which are Teltonika TRB142) are connected to the internet, so I think some kind of tunnerling would be possibile.
Do you have or can you share any documentation on how to do that?
Even a rough sketch of the system could be useful!

Thank you for any hint, it would be very much appreciated!
Giacomo

2

You can also setup a VPN of your choice, see https://openwrt.org/docs/guide-user/services/vpn/start
WireGuard is probably the most popular option these days.
SSH tunnel is one of the possible alternatives.

3

Hi @AndrewZ,

Thanks for your timely answer and useful hint.
In the end I managed to make this entire thing work using ZeroTier VPN service, which seemed to me to be the easiest option (given my VPN knowledge).
In a couple of minutes I've been able to make everything work, and I'm pretty satisfied.

I highly recommend the solution, as it is truly easy and incredibily fast to setup and operate.

BTW, thanks for you help, hope this would help other as well.

Giacomo