Unable to Use Proxy Pass to Connect to LAN Game on Same Machine

[Kas-tle]

Summary

I am attempting to use ProxyPass to connect to a LAN game hosted on the same Windows 11 PC as the ProxyPass instance.

Reproduction

1. I obtain the LAN port with:

(Get-NetUDPEndpoint -OwningProcess (Get-Process Minecraft.Windows).Id -LocalAddress 0.0.0.0).LocalPort

2. The correct port will be the first or second result, and can be tested with attempting to connect via another Minecraft Bedrock instance on the local network through the server tab (e.g. 192.168.1.3:56516). The correct port can also be obtained by connecting to the LAN game normally through the friends tab and running Wireshark.

3. I then set ProxyPass to use the correct LAN port and 127.0.0.1 for destination port
   lastly, try to connect to proxypass through the secondary device (e.g. 192.168.1.3:19122).

4. I receive a timeout error in the ProxyPass console, indicating that ProxyPass cannot reach the LAN instance.

Additional Context

I am able to successfully use ProxyPass to connect to a LAN instance run on my iPhone, so this issue would seem to be specific to when ProxyPass and the LAN instance are run on the same machine.

I have also confirmed that it is at least theoretically possible to connect to a LAN instance on the same machine by using Minecraft Preview to attempt to connect to the LAN instance in the friends tab. This of course give an outdated instance error, but that at least confirms it is trying to connect to the right place. I also confirmed that 127.0.0.1 is the correct interface and that the obtained port is correct by adding a server and the server menu, and attempting to connect to the same outdated result.

[SupremeMortal]

When starting up a local game through the client, I usually observe it starting on the default port (19132) if nothing else is bound. Have you tried setting ProxyPass to that?

[Kas-tle]

This is definitely not the case on iOS or windows for me. When I attempt to join through port 19132, I receive the error "Wow, this server is popular."

[Kas-tle]

Would there be any additional loopback issues potentially at play here that are not solved by the standard instructions given on the Unable to Connect page? I've still been struggling with this and can't really seem to figure out why this happens. I have to assume at this point that it is very much specific to Windows.