Gábor Szuromi
Assigned
No issues.
Reported
No issues.
Comments
In my experience the issue is caused by having multiple network interfaces either on hosting or on client side. Minecraft apparently transmits/listens to UDP broadcasts only on one of the available network interfaces, based on wireshark captures. If you want to make sure that the two (or more) computers can see each other, disable the unneeded interfaces temporarily before launching the game.
I hope, that this workaround can help you out until the issue is fixed.
There is another possible workaround for this problem: explicitly specify which network interface the system should use for multicast. Under linux, just add a route for network 224.0.0.0/4 with the following command:
where interface_name is the name of the network interface to use for multicast traffic.
Under windows, change the metric of the interface in question to the lowest value among all of them. Open the Advanced TCP/IP settings dialog under IPv4 settings of the interface, uncheck automatic metric, then enter 1 for interface metric. The value of 1 will beat every other interfaces with automatic metric enabled, because the lowest value assigned automatically is 5.
I hope that this little tweaking resolves your problems.