Two site VPN connection by Teltonika RUT240 cellular routers and VPN software Zerotier

Problem:
If you need an encrypted cellular connection between two sites and you are not a computer nerd, it is not so easy to create this connection (Keywords: IPv4, no public IP, etc.).

Solution:
You can use two routers for example with VPN software Zerotier

You need:

  • Hardware
    • Two Teltonika RUT240 cellular router
    • Two SIM cards with enough data volume for your application from the telecommunication company of your choice
  • Software
    • VPN software Zerotier (available e.g. for Android, Linux, Windows, [for personal use free of charge!])

Procedure:

  • Create an account at zerotier.com and set up what you need
    Important are:
    • The Network ID (1234567……)
      You need this later for the connection of your devices by this “virtual LAN”
    • The Managed IPs (www.xxx.yyy.zzz)
      You can check an later established connection from one device to an other by the “ping” command to a Managed IP
  • Install SIM card in RUT240 and configure RUT240 (APN, SIM card PIN etc.)
  • In RUT240 activate Zerotier VPN
  • If you have completed the setup on your first router you can check a successful running Zerotier network e.g. by installing the Zerotier App on your cell phone, put the Network ID (1234567……) in and ping your first router on his Managed IP
  • If all is running on the first router do the same with the second router but keep in mind, that’s a good idea to setup in the second router e.g. the private IPv4 adress range different from the IPv4 adress range of the first router.
    Example: First router: IPv4: 192.168.238.1, second router: IPv4: 192.168.239.1