How to connect two NATs using iptables?

Question

iptables

Is it even possible to connect two machines with iptables using a separate server, each of which is behind its own NAT. What would they exchange tcp packets with each other? If possible, how? I ask for a detailed detailed answer plz

Answer 1

vpn organize ... for the machines must knock somewhere and for some reason in order to unite

Answer 2

Provided that a separate server has a white static IP - you can.
Client A connects to the server, client B connects to the server, the server sends packets from client A to client B. This is how TeamViewer works for example. The simplest case is a VPN from the server to A, and a VPN to B, the server does the routing.
Which VPN - at your discretion, which one you can put. Usually either openvpn or strongswan/racoon (which implements IPSec)