How to make a remote machine available to eth0 on LAN machines connected to the internet through a shared cable modem?
Please consider a distributed software application with no configurable networking and no ability to discover peer nodes outside of its 192.168.0._ range on eth0.
What is the easiest way to expose remote instances of this application to each other over the broader internet?
IPTABLES? VPN? Network Bridge?
In other words, how can I make a linux machine connected to the internet by cable modem think that another machine remotely connected by internet is connected to the same LAN on eth0?
- This app speaks UDP over unpredictable ports. (Probably excludes port forwarding solutions.)
- Ease of implementation trumps security as the main priority, but not to the point of recklessness.
I think your best bet here would be to create a VPN between your servers. For these purposes, tinc is an especially useful tool. We have a pretty comprehensive guide that walks you through getting this set up: