@jeremy_k said in TCP connection with changing IP addresses:
You guys are seriously pessimistic about the state of end-to-end connectivity!
I am sysadmin with over 20y of experience. "I've seen things you people wouldn't believe", to quote a classic.
Serious note aside - the fact that something is possible doesn't mean one should try it. There's lots of "it depends on the use case" but I've had large enough share of commercial products with design compromising network security. That "pessimism" is perfectly warranted.
More to the topic - I personally think the OP's design is abysmal in terms of security. Can they make it work? But of course. Would I allow such a solution in the network I manage? Under no circumstances.
My advice here would be for the clients to report to the server's API at certain intervals, doing push-pull (so server would need a queue). Let's leave p2p connections for the LAN games.
Other than that I think one can make it using UPNP, where target IP is safely obtained from the server's API together with a shortlived key used to validate incoming connection on the other end, but that's borderline already.
