IPv6 internal networking – RCON connection timing out between services
frozonovic
PROOP

6 months ago

Hey there!

I'm running two services in the same project, and I’m trying to connect from one to the other over port 25575 (RCON for a Minecraft server). I understand that internal networking uses IPv6, and DNS resolves correctly to an internal .railway.internal address. However, when I try to connect using a Python socket from the bot container, the connection to that IPv6 address on port 25575 just times out.

From what I can see:

  • The target container is listening on tcp6 :::25575 (confirmed via /proc/net/tcp6 and a Python bind test).

  • DNS resolution returns a valid IPv6 address.

  • Both containers have IPv6 addresses on railnet0.

I just want to confirm:

  • Is there anything extra I need to do to allow inter-service IPv6 TCP connections?

  • Are there any known restrictions on connecting to other services on custom ports like 25575?

Thanks in advance!

Solved

2 Replies

frozonovic
PROOP

6 months ago

0693ad84-c30d-43db-af58-368c29853bd9


frozonovic
PROOP

6 months ago

This is still a problem I'm working on. Someone suggested internal proxying or tunneling so I am going to see if that works. I'm still curious why it's not working as it stands now. I haven't been able to find anything saying it won't work.


frozonovic
PROOP

6 months ago

Alright, I popped a socat binary in the container and have forwarded a local port to the server's IPv6 RCON address. This works, and the bot can successfully execute RCON commands through this bridge — suggesting the server and bot can reach each other over private networking, but something about direct IPv6 connectivity is going haywire.

I'd love insight on:

  • Whether direct IPv6 connections between services are supported or intentionally restricted

  • Whether exposing a second port internally or setting up a reverse proxy is a better long-term solution

Much appreciated for the help.


adam
MODERATOR

6 months ago

!t


adam
MODERATOR

6 months ago

This thread has been escalated to the Railway team.

Status changed to Awaiting Railway Response adam 6 months ago


adam
MODERATOR

6 months ago

ipv6 not working for internal networking


sarahkb125
EMPLOYEE

6 months ago

Hi there - for internal networking - exposing a second port internally or setting up a reverse proxy is indeed a better long-term solution


Status changed to Awaiting User Response Railway 6 months ago


Status changed to Solved sarahkb125 6 months ago


frozonovic
PROOP

6 months ago

After further review, I have come to the conclusion that the library I was using forced IPv4 connections. I have since made my own small class for this project, tested it, and achieved what I was attempting to do with private networking. Thank you for the help.


Status changed to Open Railway 6 months ago


adam
MODERATOR

6 months ago

Glad to hear you've solved the issue! Marking this as solved


adam
MODERATOR

6 months ago

!s


Status changed to Solved adam 6 months ago


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