Unable to connect to server

[ajnozari]

I have a server that was working previously (before 1.19.20). My client updated today but now I'm suddenly unable to connect?

Not sure if something changed but I even tried re-creating the world entirely (fresh install) and I still cannot connect.

[TheRemote]

Hey ajnozari,

Nothing has really changed no. I'm surprised you're getting it with a completely fresh install. There have been a few people that have had crashes after some of the upgrades but these all turned out to be corrupted servers.

Yours seems like a different issue for sure. What is your host OS? Is it running something like Ubuntu 20.04 or older? If so it may just getting too old to run the latest dependencies that Microsoft is linking to. The reason this came to mind is that when people's break out of the blue with really strange issues like this it has been that their OS was aging and needed an upgrade.

At the very least there's no recent changes that could explain this. I only recently added a clean.sh script that basically forces it to download and install the latest server version. It could be related to updates to the Minecraft binary itself like what Microsoft is linking to.

You could try running the old version with the version override / pin_version.txt theoretically if you remember the exact old version. It would be interesting if this solves it. I wouldn't necessarily expect this but it's possible if Microsoft changed dependencies and this is not the latest version of your OS.

I take it you are seeing nothing when trying to connect in either the server console or on the client or you probably would have mentioned it. Some more information about the environment may help if none of this helps solve it. I'm not totally sure about this one yet but wanted to let you know what I could to help aid with investigating this a little at least!

[ajnozari]

It is 20.04. Ill do a dist upgrade and see if that helps

[ajnozari]

As an update I have upgraded to v. 22.04 and I'm still having issues. I have the server backed up, I'm going to re-install the OS entirely and see if that helps.

To answer the other question I cannot even connect to the server. I just get a connection timeout.

It's a Ubuntu 22.04 LTS VM with 6c, 6gb DDR4 ram, running off an nvme ssd.

Update: I have even tried to use the docker image but it didn't change anything.

[TheRemote]

Hey ajnozari,

Check the firewall for sure. Most people who have been having issues on Ubuntu either have ufw (universal firewall) or firewalld installed. These are not installed by default on Ubuntu BUT people who use VMs often have them enabled anyway (by the provider).

Is it Oracle? If it's Oracle I can tell you the exact answer because that one comes up all the time: https://jamesachambers.com/official-minecraft-bedrock-dedicated-server-on-raspberry-pi/#comment-13946

Basically the only explanation here is firewall (probably enabled without your knowledge by the VM provider).

ufw allow 19132

or

sudo firewall-cmd –permanent –zone=public –add-port=19132/tcp
sudo firewall-cmd –permanent –zone=public –add-port=19132/udp
sudo firewall-cmd –reload

will probably do it. I couldn't tell you why this started when it updated and was working before. It may have had nothing to do with the Minecraft update and may have been a change through the VM or package manager. It's hard to say but 22.04 is definitely a working / main distro for it so there must be something else enabled (very common with VMs).

If this is a Hyper-V VM the answer is something different. It's definitely configuration though and not the scripts / Minecraft server. I think I've seen them all at this point so knowing what yours is I can probably tell you which ports to open or how to configure it.

[ajnozari]

The UFW is inactive that's what is weird. That was definitely the first thing I checked.

The logs also don't show anything special, it's like the entire VM just isn't responding at all.

[TheRemote]

You can use wireshark and do a packet trace if you'd like. I really doubt traffic is flowing. We've troubleshooted a Hyper-V VM and found out it had a faulty virtual adapter once and they had to change the VM network adapter type.

I've only done it one time but you can install wireshark if you're positive that traffic is flowing and that may reveal a different issue. It did in that case!

Out of the last 3 that had this none of them had ufw and all of them had firewalld installed. They did not install it. They were also all Oracle which is definitely the most problematic and difficult VM to configure out of all of them. I would guess this has to be Oracle or Hyper-V. I almost never hear anything about any other setups but yours might be a new one (that definitely happens).

Oracle requires creating a virtual adapter security group and a few other things that are in the link I linked to earlier. It will not just work unlike almost every other VM out there.

[ajnozari]

This is Hyper-v. I know that older versions of ubuntu used legacy network adapters but i'm on server 2019 so I only have one version available and it was 100% working before.

[TheRemote]

Oh boy. I was afraid you were going to say it was Hyper-V! Okay, that is literally the one that we did the only Wireshark trace I've ever done troubleshooting this.

It's literally the weirdest issue I've ever seen and yours is a 100% match. I bet if you install wireshark you will see the exact same thing we found before. Here's a link: https://jamesachambers.com/minecraft-bedrock-edition-ubuntu-dedicated-server-guide/#comment-13863

The answer ended up being this:

I switched the VM to back to using Generation 1, and selected the legacy lan driver in hyper-v, it’s working now.

Must be a bug of some kind in the Linux Hyper-v lan driver for the Generation 2 vm spec.

However your message concerns me a little bit. Is this not possible for you? Does 2019 not let you create a Gen1 VM anymore?

[ajnozari]

It does, however the weird thing is, Ubuntu natively supports the gen2.

I'll try making a new gen 1 and give it a test.

[TheRemote]

Excellent, I am sure this will get it for you. I don't know why it happens. It's not just the Minecraft server that is impacted: microsoft/WSL#6082

It's a UDP bug in the network stack. This is a Hyper-V only issue and we've only seen it one time ever and it was only 25 days ago. It's been around for a while. Since the beginning of V2 from what I can tell.

Couldn't tell you why it's not fixed now and wasn't fixed months ago. It seems important!

[ajnozari]

This must be a new bug since everything was working as of like a week ago. Thanks MSFT

[TheRemote]

It could have to do with how they are linking to the libraries. They seem to be switching between libssl1.1 and libssl3 (right now the server links to both libraries).

It is pretty interesting that yours was working before and broke. I couldn't explain that other than it was definitely something Microsoft did and that there's no explanation within the scripts that I've done at least that would make any sense to explain this.

Yours actually was working when this person's broke. That's another weird thing about this. I take it this did not break 25 days ago but the other person's did. Why now? Why didn't yours break on the same version that person's did? That's a mystery for another day probably.

I'm glad you got yours going, enjoy and take care, let me know if I can help further!