This is something similar what cjdns does. Any peer who wants to connect to another peer need to exchange their connection info (public ip, port, password, public_key). That makes a friend to friend network. The same concept IOTA uses.
But, in cjdns if it finds any other node around which is running the same software it auto peers with it. That's called beacon mode in that software.
Instead of using friend to friend option to connect to other peers, nodes can also use network card's MAC address under beacon settings and it connects to them without exchanging any other info.
I think something similar should also be possible and be included in IOTA.