ZeroTier Cellular Data Connection Issues

[brad]

Hi guys,

A client of mine if having major issues connecting to his mail server via ZeroTier with using Cellular data.

A few details;

The VPN works fine with WIFI connection.
Client cannot search the internet on cellular with the VPN connected.
Cellular works fine without the VPN connected.
The device is a Samsung A21.
Provider is Telstra.
I have checked Cellular data is enabled in Android settings.
Client has removed, re-installed app & re-added himself to the Network.
Client is approved in Zerotier Portal.
Clients status on Zerotier is all as expected.

I’m troubleshooting this remotely which adds a layer of difficulty.
If anyone has any ideas about this or can identify something I have missed that would be great.

[toni_13]

Hi, I’m joining the topic. I have exactly the same problem. When I’m on wifi no problem. When I turn off the wifi on my phone and connect only via LTE, I have access to my network resources, but not the internet on the web.

[toni_13]

The solution is ridiculously simple, I checked the ZeroTier RFC4193 (/ 128 for each device) option and it works

[brad]

Hi Toni,

Where is the option exactly? Unfortunately I don’t have an Android so can’t explore myself.

Cheers

[toni_13]

On my.zerotier.com there are 3 options for IPv6 to choose from. I chose the first one and that solved the problem.

[dmkjr]

Seems maybe the provider must block the IPV4 addresses traversing but allows ipV6?

[toni_13]

In my case, the ISP wrote that the APN settings do not block access and the IPv6 settings in the VPN need to be verified. It’s always a good idea to ask your ISP.