I am searching for a robust way to access my computers (on any port when possible) whether they are behind several NAT gateways or not. By robust I mean I want to access the computers whenever they are powered up, even in cases when I don't have configuration access to the router, or I am behind certain firewalls with blocked ports, etc. I would like to do this with a least amount of maintenance. ;) Ideal would be a tool I just have to configure one time and that's it. I know I will need at least one public computer for that kind of scenario where all my computers could connect to and sign themselves on/off. (Is there something like a P2P solution to that?) Operating systems involved so far: Ubuntu and Mac OS X. (Windows would be nice too.) The most used service would be ssh, so also ssh-tunnels came to mind. I don't consider them robust, as I cannot configure them when I am not at the same place as my computers, and I don't give away passwords. Also OTPs aren't a solution!
Is (Open)VPN the solution to my problem?
BTW: I consider DynDNS, ssh-tunnels and port forwarding as not robust enough, but correct me if I am wrong! Also I've read many similar questions only focusing on parts of my question. I want to solve this problem now and forever! ;)