LAN games no longer work with ZeroTier

I got ZeroTier so that I could play games on LAN mode with my family.

For some time, it worked and I was able to play Minecraft, Battlefront 2 (2005), BFME 2 (Age of the Ring 8) and others no problem. However, at some point it just stopped working.

I reckoned at first it was an issue with Windows Firewall (all devices are Windows 10 or 11). However this does not seem to be the problem, as when devices are on the same real network, LAN connectivity works. However, when they are on different networks the LAN connectivity through ZeroTier doesn’t work.

Picking up the issue again recently, I tweaked the IP setting in ZeroTier and got devices to show up in the lobby (BFME) despite being on different networks (I used a hotspot for a device and home network for others). However after a few minutes they disappeared, now I am back to square one and unable to reproduce this. This really confused me. The change was I went from 10.* to 192.168.*.

Since the games all work when on a real network, and since they worked on ZeroTier in the past, I find it difficult to believe that it is some problem besides ZeroTier or some ZeroTier-Windows interaction.

I am finding limited information about this particular issue and wondered if anyone had any pointers, at least in the area of diagnosing the problem. If more detailed information on anything is needed, I can provide it. Thanks!

I hope you don’t mind me leaching off your post but I am also experiencing a similar (ish) issue. In this case I am trying to get an older version of Civilization (Civ IV - best version to exist!) … anyhow… actually ran into an issue with Steam where they limit human players to 4 per game so I turned to ZeroTier for a possible solution and thus far have had only partial success. Basically for Civ IV to work multiplayer with the version I’m using and with the larger player count it has to be a LAN game but I have players in two or more physically different locations (hence why I first was drawn to check out this software).

For testing locally I hotspotted one of my systems to simulate being on different networks and had two other systems on my actual home network all with zerotier installed and connected to the same zerotier network. Here’s where it got interesting… I can so far only get partial functionality where a game hosted on one laptop did show as a lan game to the other laptop (across different networks) but a 3rd system even with a brief test to eliminate potential firewall issues never could see my test game.

I will of course be conducting further tests including exploring other solutions but it would be simply amazing to get this to work properly. Is there something simple I could be overlooking? It sounds like my issue and the issue as described by the OP are possibly quite similar. Thanks in advance and to the OP, … sorry about hijacking your post but I figured since the issues are near identical a separate post would be redundant.

Edit: All involved systems run either Windows 10 or 11.

I think it is most likely a Windows issue. I had the opportunity to get my Ubuntu server up again, and it works perfectly fine with ZeroTier. All Linux+Windows machines (around the country) on the network were able to join a Minecraft server hosted on the Ubuntu server. However it seems the Windows machines are all invisible to each other beyond pinging in the terminal despite any changes I try to make. For now my “solution” is to just use Linux.

You bring up an interesting point. When setting up a windows computer on a network at some point you are asked if you want the machine to be discoverable to others on the network. I’m going to see if I can figure out something from that angle as my solution has to be easy enough for me to describe to someone over the phone. Maybe I just have a bad setting on one windows machine.

Hi!
I’ve seen the problem you were facing. Today I could manage to make it work after some attemps with different methods.

In WINDOWS:

From
https://answers.microsoft.com/en-us/windows/forum/all/cannot-see-any-computers-in-network-windows-11/961df2f7-3387-4bfb-82e8-e095c33593ae?page=1

Do the following steps:

Turn on network discovery and file and printer sharing, and turn off password protected sharing.
Select the Start button, then select Settings > Network & internet , and on the right side, select Sharing options.
Under Private, select Turn on Network discovery and Turn on file and printer sharing.
Under All Networks, select Turn off password protected sharing.
Make sharing services start automatically.
Press the Windows logo key + R.
In the Run dialog box, type services.msc, and then select OK.
Right-click each of the following services, select Properties, if they’re not running, select Start, and next to Startup type, select Automatic:

  • Function Discovery Provider Host
  • Function Discovery Resource Publication
  • SSDP Discovery
  • UPnP Device Host

Then do the following:

  1. Press Windows key.
  2. Write “Windows features” and click on “Turn Windows features on or off”.
  3. Look for SMB 1.0/CIFS File Sharing Support.
  4. Mark the checkbox.
  5. Apply changes.
  6. Reboot PC.

This should be enough to make it work. If not, please let me know. Maybe I modified something else and you should do it too.

Edit.
In addition, you’ll have to change the internet adapter configuration.

For that, you have to go to Control Panel → Network and Sharing Center → Change Adapter Settings (left menu) → Double click in the adapter ZeroTier.
There, you have to go to Properties and under “Networking” tab, double click on “Enable Internet Protocol IPv6”.
After that, go to advanced settings and in the lower part of the pop up window, uncheck “Automatic Metric” and set it manually to “1”.

These steps should be done for everyone who want to join the server.

I hope it solves the problem you’re facing!

Were able to get it to work? I have the exact same issue with civ 6.

I could make it work doing what I explain in my reply.
Have you tried it?

I didn’t test your solution yet. I wanted to find a few solutions and then go try them with my friends. They have very little patience haha. A question about your solution though, I should use IPv4 though instead of 6 i think. My ISP is using v4 and similar solutions i found online had v4 too.

I’m not an expert on that subject, but for me and my friends it worked by changing the IPv6 configuration as I said.
You could try doing the same with the IPv4 configuration and see if it works.

Let me know if you can make it work.

We only did the network priority thing. We did for IPv4 and IPv6 at the same time, unsure which one did the job but it worked! Didn’t bother trying anything else from your list though.

Thanks!