Network n00b here.

I have 'dumb' monitoring devices attached to a LAN via Ethernet. Using a desktop app on a PC within the same LAN, it is very simple to connect and to obtain the monitoring data.

Now I need to network these devices such that they can be accessed from a desktop app on a PC in a different LAN only connected via the internet.

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I have looked at:

  1. TCP/IP communication;
  2. Monitoring devices connected to a VPN router - connected to the LAN

We can't use 1 because it is unsecure and we have no access to the LAN config. 2 is great because it's secure but the PC with the desktop app would also need to be connected to the VPN so the user would have to install the VPN client software and we can't automate the process. Would there be a way to automate the process? Is there something I've missed?

  • 1
    Virtually every site connected to the Internet has some sort of firewall, and very likely address translation. That complicates matters even more. What kind of dumb device is it?
    – Ron Trunk
    Nov 16, 2015 at 16:37
  • Yes, I didn't want to model all the places that there would be firewalls, the device is a board, PIC and Ethernet card. All communication is external.
    – xhedgepigx
    Nov 17, 2015 at 9:42

1 Answer 1


I can't think of any way to accomplish what you want without making major changes to your design. Fundamentally, you want to make inbound connections to networks you don't control. Also, you want to install software on PCs you don't administer with minimal or no user interaction.

You are mimicking what hackers and malware do.

Here are a few thoughts:

I think you need to change your design so that the devices make outbound connections to you (a server on the Internet, for example). That eliminates all the problems with firewalls, NAT, etc.

  1. You could write a program that reads the data from your device and then makes outbound connections to your server. You can use SSH for confidentiality, and the program would be lightweight enough that you can automate installation. But this may require more programming skills than you have. You could possibly use free software like Putty to do SSH tunneling -- I'm just thinking off the top of my head ere.

  2. You could modify the dumb device so it makes connections directly. But again, that requires modifying the devices. That may not be practical either.

  • Thank you - this is along the lines of my own suggestions to The Management which weren't good enough. However the programming in (1) is my day job :) I'm merely a code monkey rather than a networker. I'm glad I haven't missed anything.
    – xhedgepigx
    Nov 17, 2015 at 12:23

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