[2.0.32] LAN games not browsable across subnets

[Scatty]

Not an in-game issue per se so no log files attached.

My friend's local network has a router, and a Google Nest mesh for WiFI. Devices on ethernet are connected directly to the router and exist on a 192.168.1.0/24 range, where devices on WiFI are connected to the Nest and receive IPs on the 192.168.86.0/24 range. These subnets have full traversal, you can ping across them, you can ARP across them, they show up in Advanced IP Scanner etc.

Hosting a game on either network is discoverable via Browse LAN Games by any devices on the same subnet, but don't exist for devices on the other. This is likely because Factorio is only polling IPs on a subnet matching the client. This could be improved by having the client scan for local subnets when clicking the Browse LAN Games button, then iterating through all ranges on all IPs for LAN games. There may be a more elegant solution, and if any team would find it, it would be the Wube guys.

While most Factorio players are likely above-average on the troubleshooting side of things, this is quite easily avoidable and many networks may actually struggle to get around this, and if they don't use direct IP connections (which work fine until next session when DHCP leases have expired) then they may resort to hosting and authenticating over the internet even though they're on LAN.

Found one similar thread from last year, which received no responses, in tech help. Exactly the same issue, though perhaps obfuscated behind the headless server aspect, where the issue is pure subnet traversal.

viewtopic.php?p=616899#p616899

Thanks for your amazing efforts.

[Rseding91]

Thanks for the report however Factorio does not poll for LAN games, the server broadcasts and clients listen for that broadcast. It sounds like the broadcast is not being sent across your subnets - which matches how broadcasts are designed to work and is not something we can change on our end.