We’re developing a small multiplayer capability that is intended to work with no internet access, on a standalone network (2 computers connected to a switch). When these computers are connected to a switch with no internet, we can’t join a session. When we connect the switch to the internet, via ethernet, we can join the session and everything works.
I thought the whole point of the Null subsystem was to provide an offline solution? We’re using UE 5.2.
We found the issue. Looking at Wireshark logs, Null still reaches out to a DNS server if the computer IPs are dynamic. Setting all computer IPs to static and specifying an IP address for each allowed us to run on a standalone network.