OpenVPN on iPad with personal hotspot on iPhone: network is unavailable

Kirschi37

Hi all,

I just got myself an iPad (M2) I wanted to use for company purposes. So I wanted to use it to connect to company network with OpenVPN client. I already have a Macbook Pro (Intel) where it works without problems to connect to my personal hotspot on my iPhone and then from the MBP to my company network. However, I use a different VPN Client there (Viscosity). From my iPad when in the same scenario trying to connect with OpenVPN I instantly get a network is unavailable message after typing credentials. It works fine however when connected to usual WiFi. Is that a known issue? Either with OpenVPN using personal hotspot? Or OpenVPN on M2 processor? Or something else? If there is no solution can someone recommend a different VPN app for iPad?

Btw: The other side is a Sophos firewall but that should not be of interest here.

Thanks in advance
Daniel

JosephS

Hi Kirschi37,

Can you share the output from the app logs whenever you are receiving "network is unavailable" message?
Perhaps there is a scenario where your VPN server on the Sophos firewall is set up to only support IPv4 traffic, but the hotspot sharing is working with v6 exclusively instead of dual stack.
That's just a wild guess, but hard to say without having a look at the logs.

With Regards,
JosephS

Kirschi37

JosephS Sorry, Joseph, but the log file does not log anything in that case. I can only see log entries from the successful connection attempts via WiFi from yesterday.

Btw: Here is the complete error message:

Connection failed
There was an error attempting to connect to the selected server. Error message: Network is unavailable. Please try to connect later with active network.

Any other network connection to internet is working fine however through tethering.

tomi8473

Exact same here with my iPad. Does anyone have solution ?

This issue only occurs when the device is connected under iOS(iPhone) hotspot.
No issue in case iPad directly connected to WiFi/5G.
No lucky with reset iOS and just install OpenVPN app.
No log entry logged even if verb 9 set in the profile.
Version info: iOS 26.4, iPad OS 26.4, OpenVPN app 3.7.2(6402)

JosephS

Intersting.

Can anyone check an and confirm if the hotspot network that is being shared by the iPhone is exclusively IPv6?

I may be wrong, but I believe a bug like this used to exist on older macOS Connect App versions and it was only reproducible when being connected to a IPv6 only hotspot. (DualStack and IPv4 only worked fine).

tomi8473

Hi JosephS,

To answer the original question: No, the iPhone hotspot is NOT exclusively IPv6. It provides a Dual-Stack environment to connected devices.

However, I want to share my factual observations regarding why we get the "Network is unavailable" error on OpenVPN in this environment.

[Observable Facts on current iOS/iPadOS 26.4]
When an iPad is tethered to an iPhone operating on an IPv6-only cellular network, the following network state is observed on the connected iPad:

The iPad successfully receives valid global IPv6 addresses.
Instead of receiving a traditional 172.20.10.x IPv4 address from the iPhone, the iPad utilizes its internal 464XLAT (Self-CLAT) and assigns itself a virtual IPv4 interface:
- IP: 192.0.0.2 (RFC 7335 - IPv4 Service Continuity Prefix)
- Subnet Mask: 255.255.255.255 (/32)
- Gateway: 192.0.0.1

[The Issue with OpenVPN Connect]
All other internet-bound applications work perfectly fine in this Dual-Stack state. However, OpenVPN Connect immediately throws the "Network is unavailable" error and halts.

This indicates that the app's pre-flight network detection logic (or the underlying OS API it calls) seems to fail to recognize this specific 192.0.0.2/32 interface as a valid, active IPv4 internet connection. FYI, my openvpn server destination is IPv4.

[Workarounds Tested (and Failed)]
I have already tested the following common suggestions, and they do not work or are not viable:

Manual IP Override: Manually changing the iPad's IPv4 settings to a standard /24 subnet (e.g., Mask 255.255.255.0) does NOT bypass the app's error.
Changing Carrier APN (Not possible): Modifying the iPhone's cellular APN to force IPv4/IPv6 is physically impossible for users whose carriers lock the APN settings.

[To the OpenVPN Dev folks]
Since there looks no viable on-device workaround for users with locked carrier profiles, an app update is critical. Could anyone from the development team please review the network state detection logic to ensure it properly recognizes Apple's modern Self-CLAT environment (192.0.0.2/32) as an active network?

JosephS

Thanks for the detailed description tomi8473.

We tried to reproduce this issue in-house and we couldn't.

After talking with the Apps dev team we think that the best approach to investigate this further is to have a look at the iOS system logs that are generated during the VPN connection attempt.

For that we would ask you for the following, if possible:

Have your iOS device already connected to the hotspot.
Connect the iOS device to a MAC via cable.
Launch the Console on macOS ( Applications > Utilities > Console)
Select the iOS device from the list of "Devices" and press on "Start streaming"
Attempt the VPN connection on the iOS device
As soon as you see the "Network Unavailable" message - pause/stop the log streaming on your macOS console.
Share the console log outputs by sending them to support@openvpn.net. Just put a tittle in like "iOS logs requested by Joseph" or something along those lines.

I know it's a lot, but let me know if that sound feasible.

tomi8473

Hi JosephS,
Thank you very much for your guidance! I've sent the e-mail.

JosephS

Thanks for providing the console logs tomi8473.

The Apps dev team will look into them.

Also can you tell me what the "Connect Via" option is set to in your Connect App's setting on your iPad?

tomi8473

Hi JosephS,
"Connect Via" option is set to "ANY NETWORK" as default.

JosephS

Thanks for your cooperation on this tomi8473

We will introduce an improved API for network status check for the Connect App on iOS that will hopefully resolve the issue you are experiencing.

The fix will be part of our next iOS version release, aiming to be delivered this quarter.

tomi8473

Hi JosephS,
Thank you for your support! I am looking forward to it.

JosephS

Hi @tomi8473

OpenVPN Connect version 3.7.3 has been released on iOS It includes the fix we've been discussing in this thread.
Please give it a try and let us know how it goes.

With Regards,
Joseph

tomi8473

Hi JosephS,
I've tryed new version of OpenVPN connect app on my iPad 26.4 and now it works !
Thank you so much for your support !