Multiplayer server - friends can join, I cannot

[youngyyoungyoung]

Hello all,

I have set up a Linux (Debian) OpenTTD dedicated server to play on. I have asked two other people to join, and they can connect easily and quickly with no problems. However, when I try to join on a different computer, it shows connecting for a while then gives a "The server didn't answer the request" error message. In the console output when I click "spectate game" or join a company, it shows the normal "Client connected from [ip] on frame [number], but immediately afterwards it shows "Closed client connection 14". In my client, the "connecting" message shows for maybe 15 more seconds then exits with the error.

I have browsed many different threads on this forum and others, and have not found a solution. I have checked all the common tips I have seen.

Both port 3979 and 3978 are forwarded and let through the firewall with ufw.
Port 3979 is visible with a port checker.
The server is advertised and lan in the config file is set to 0.
The server is visible and shows online on both the OpenTTD website server list and my client.
As mentioned above, two other people can connect with no trouble with the same IP and server name.
There are probably others, but these are all I remember right now.

I have tried joining other multiplayer games on my computer and they work quickly and without problems, but for some reason this specific server has issues. I've tried turning the firewall both on and off on both my computer and the server computer, but it does not work. I had it up yesterday and I was able to join after many attempts, but I have tried about 30 times today with no success. I have another server application running on the same computer, but it is on a different port.

Thanks very much for any help, I am at the end of my wits.

EDIT: I restarted my computer and I can magically join again after a few seconds. However, I would still very much appreciate some tips as to possible solutions so this does not happen again. Thanks again.

EDIT 2: I can't join again, obviously the problem wasn't solved by the restart.

[jfs]

Is the server running on your home network or an externally hosted server?
If it's on your home network, try connecting via the internal network IP instead of the internet-visible IP.

[youngyyoungyoung]

Is the server running on your home network or an externally hosted server?
If it's on your home network, try connecting via the internal network IP instead of the internet-visible IP.

It's on my home network. I tried using the local IP and it worked great, thanks very much.

As it turns out, I believe the problem is due to this thing called NAT reflection not being supported by my router.