Free program for remote control of a computer whose IP changes regularly?

Question

Network administration

Good afternoon, please tell me if there is a solution:
I want to manage 4 laptops on Linux in the next room from my PC (Windows), the nuance is that they regularly (as necessary) reboot the 3G Modem and resp. the IP address changes and programs such as AnyDesc knock out and do not want to connect again (apparently because the IP is not the same).
Which of the free ones can be used to manage laptops? (Timweaver is not good, because after 5 minutes it starts beating and telling me to buy it :-))

Answer 1

In order not to be bound to ip, you can use services like no-ip.com

Answer 2

Because on 3g modems you probably only have gray IPs, then the iron option is only 1: buy a VPS with a white IP, deploy a VPN server there and connect computers to it
. On it, forward ports for management and manage any software using already known permanent IP

Answer 3

Look for RMS, as well as teamviewer can work through someone else's online server if you assign id to managed computers.