Forced update by Mojang. It’s impressive that, until yesterday, a single version of Proxy Protocol Support could handle versions ranging from 1.13 to 1.21.11. Minecraft 26.1 has done away with game code obfuscation. Had it not been for that, the previous version would still be working. In fact, it would still be working; all that was needed was a recompile to disable the remapping. Interestingly, the server listening code hasn’t changed at all! Impressive...
Now, you can simultaneously accept connections from a trusted proxy (using the PROXY protocol) and from trusted direct-access IPs. This is perfect for setups where you want to hide your server's IP behind a proxy, while still allowing admins or local players to connect directly. (#22) (Thanks @jtnqr!)
For this reason, the configuration has been slightly modified. For more information, please see the README.md file.
io.netty:netty-codec-haproxy from 4.1.114.Final to 4.2.7.Final4.1.91.Final -> 4.1.112.Final0.14.17 -> 0.16.37.2 -> 8.10Should still work on Minecraft versions 1.14-1.21.1
First version for Forge, tested with:
Lower versions currently not working

Proxy Protocol support for Fabric servers