Zerotier not working on cellular data Android 1.14.0 - Samsung S21+

[JaJe92]

This problem also happened on previous version prior 1.14 but on older versions of software it worked and all of sudden it stopped. I really need this and I ran out of options to fix this.

• What you expect to be happening. To work as intended in both Wifi connection and cellular data.

• What is actually happening? Whenever I connect to 4G/5G Network, Zerotier refuses to just connect to the network no matter what I do.

• Any steps to reproduce the error. I tried to clean cache of app, force close, clear everything and reconfigure the settings on phone, then reinstall it completely and remove the device from zerotier network and add it again, still nothing.

-Any relevant console output or screenshots. I attach screenshots on my phone while I am on 5G that is offline and as soon I get into wifi, it will connect to the network and works.

Sometimes on 5G it appear the lock key that is connected to vpn but still offline like below.

-What operating system and ZeroTier version. Please try the latest ZeroTier release. Samsung S21+ 5G Android 14, One UI version 6.1 Kernel version 5.4.242-28575149-xxxxx

[joseph-henry]

Thanks for the report. Who is your service provider?

[JaJe92]

Orange Romania

[Ponkos22]

I have same problem with Orange Poland. With t-mobile on second phone is OK

[JaJe92]

I have same problem with Orange Poland. With t-mobile on second phone is OK

Thank you for confirming this, I am unable to test with another provider as everyone I know is using Orange only. I'm more convinced that it's the ISP fault at this point and they did changed something on their network without informing public that the network have been changed as I haven't found any information on their website.

[joseph-henry]

Unfortunately it does look like your ISP is blocking either our endpoints or certain encrypted UDP traffic. It's hard to tell. I think our only recourse in cases like this is to just file a complaint ticket with your ISP and trying to get clarification. I'm sorry.

If you're in a situation where the node can come online but it doesn't talk to other nodes, you can try:

In other discussions with clients reporting ZeroTier not working over cell radios we've realized that some devices along the path might have insanely small MTUs. So if you change your ZeroTier network's MTU to something much lower it might allow connectivity at the expense of traffic. You can play with the number to find one that works best for you.

In Central, you can create an API token and use it like so:

curl -X POST -H "Authorization: token xxxxxxxxxx" https://api.zerotier.com/api/v1/network/<nwid> -d '{ "config": { "mtu": 1280 } }'

Where <nwid> needs to be replaced with your network ID.

Some people have reported that setting the MTU to something like 1280 really helps. But this will have a noticeable performance impact.

[Pinkbyte]

I am having the similar issue (not working on cellular data after upgrade to 1.14.0, works on Wi-Fi just fine) Rolled back to 1.12.0 for now

[JaJe92]

I am having the similar issue (not working on cellular data after upgrade to 1.14.0, works on Wi-Fi just fine) Rolled back to 1.12.0 for now

I've done the same, unfortunately none of the older version of Zerotier apk don't work on my case.

[mstevanak]

I have a similar problem: On wifi it's OK, on celluar data I'm getting request time out, occasionaly I get OK response.

[bremenpl]

Exact same problem, also Orange, Poland, phone...

[tomV81]

I have the same problem with connection via GSM (Vodafone CZ). Zerotier is posting online but I can't connect. Ping doesn't work either. Zerotier currently in version 1.14.0-2, but also tested version 1.10. Everything is fine on Wi-Fi.

[boykov]

I have a similar problem with connection via GSM (Megafon). Ping doesn't work, OFFLINE status. Version 1.14.0-2. It works on Wi-Fi. A laptop (1.14.1) connected via smartphone Wi-Fi access point works fine too.

Upd. I somehow forced the app to work. Here are approximate steps:

• Just installed fresh app doesn't work via GSM, no ping, OFFLINE status
• Connect it via Wi-Fi and check the capacity for work: ONLINE status, connected to the network.
• Then using android "Applications" stop the app and clear the cache (I think it's an analog of "purging" in the case of linux https://discuss.zerotier.com/t/zerotier-cli-shows-offline-zerotier-gui-shows-connected/138/5 )
• Change Wi-Fi to GSM
• Start the app, now it's ONLINE via GSM and ping works.

I'm not sure that these steps work in any case, but I've already got working app after few fresh installs. And it continues to work now.