How to connect different devices for multiplayer via LAN without IP?

I’m working on a simple “hello multiplayer” in which all I want to do is connect different devices together on the same network (or via LAN) without the need for exchanging an IP address. Currently I can connect devices using the console command open “ip address”, and only if I am on the same network (I’m assuming it would also work on a different network if I port-forwarded, but that’s not the objective). I’m trying to use the find sessions and join session nodes to do it, but I don’t understand the online subsystem too well. The nodes approach does work when running two instances of the game on the same computer, so I know I’m close, but when trying to connect the computer with an Android device, neither the computer nor phone can find the server (I tried both ways). Don’t know what the problem is, I did try editing the engine.ini file to make the online subsystem NULL, and I also tried setting it to LAN.

I have also tried connecting two android devices, but to no avail. I know the network is good because I can establish a LAN connection on an actual mobile game I have on both android devices.

Thanks in advance!

I used to have this working on my game, but when the release date came, it suddenly didn’t work anymore for Android to find any sessions.

I have an issue like this, FindSessions behaves the same way whether there is an active session at the moment or not. The same code works fine when two game instances are launched on the same Windows device. I was tired of debugging this so I tried manually typing an IP address and calling ClientTravel, but no luck there - it just didn’t do anything. Maybe you have found the solution?

Unfortunately, I haven’t. I ended up resorting to using ip addresses. I did find a nifty way to make the game automatically display their own ip address to the user when trying to host, so then they can just share it with friends on the same network. That system works fine, but ideally of course I’d love to find a way to automate the whole process so users don’t even have to think about ip addresses.

I’m not sure how much of this applies in 4.27+, but:

blocking UDP broadcasts at the receiver, or at the network router, can be a pretty nasty problem to get around.