Android Auto VPN

Fname

Android Auto will not connect with VPN running and disconnects when VPN is turned on. Is there anything GrapheneOS can do to fix this issue?

Kottonballs

Which VPN and is AA wireless? I'm using ProtonVPN with wired AA without issue.

Fname

Kottonballs I was wireless using Bluetooth. Are you wired to the car?

doodle

AA creates a wifi network between the car and the phone to operate in wireless mode. It can't work with VPN enabled, unfortunately

Fname

doodle If it works with VPN if wired then we are exposing our phone to the automobile manufacturer. Wireless then exposing our IP to Google and the automobile manufacturer. Sofie's choice

de0u

Fname If Android Auto is connecting to your car using IP over Wi-Fi, the IP address of the car will inherently not be globally routable. If your device sends packets addressed to the car to a VPN server, the VPN will have no choice but to drop them.

The only way to use Android Auto over IP while running a VPN is to configure the VPN client to leave the traffic to the car alone. This is not a bug in GrapheneOS or a bug in Android Auto.

0xjac

I'm having the same problem using Mullvad VPN and a Carlinkit 5.0 (2air). I have tried with the exact same phone with stock android and Mullvad and other phones (stock OS) and Mullvad without issues.

But with GOS, wireless AA keeps showing me an error that my VPN is enabled. I've tried adding either AA to Mullvad's split tunneling and all available apps (including system apps) to split tunneling but nothing works. I've also tried to have a fixed MAC address for WiFi to no avail (just in the case the randomized per connection MAC address was messing things up). The GOS toggle for wireless AA is obviously enabled. Wireless AA without VPN works just fine, and so does wired AA with the VPN on.

Tested with:

Pixel 8
GOS 2024012600 (latest)
Mullvad 2023.10 (latest)

I believe the issue might be on the GOS side rather than the VPN side since the same version of Mullvad was working fine on the same hardware with stock Android (and just AA added to split tunneling). My guess is that some shim made by GOS for wireless AA must be added to Mullvad's split tunneling but is not shown on the list of apps (including system ones) for some reason.

@Kottonballs did you manage to get wireless AA working with ProtonVPN as well and if so could you share the settings you used to get it to work?

Kottonballs

Unfortunately, I only asked it you were having the issue wireless as wired seemed fine. I don't have a wireless AA to test with.

Carlito

I am also experiencing the same issue; whenever I try to connect to Android Auto, the headunit is just blank, and I receive the following error message:

Android Auto encountered an error: Communication error 21 - Being connected to a VPN may prevent Android Auto from starting. If you're using a VPN, turn it off and try reconnecting to Android Auto.

I have tried turning off Android Auto and reconnecting, however doing so still causes the same error and failure to connect. I have also tried running split tunnel mode on the VPN, and excluding Android Auto. That has not made any difference either. Is there something that I am doing wrong?

Pixel 7 Pro
Proton VPN
GOS build number: 2024070201

de0u

Carlito How about disabling the VPN?

Carlito

de0u Oops. My reply above indicated that I turned off Android Auto; that is a "typo". What I should have said would was "I have tried turning off the VPN", which in reality is what I did.

I also tried temporarily uninstalling the VPN. As expected, Android Auto then started working again. However, I would really like to be able to use both a VPN as well as Android Auto.

de0u

Carlito I would really like to be able to use both a VPN as well as Android Auto.

Understood, but Android Auto is complicated and has requirements. In particular, wireless Android Auto uses network protocols in a way that are easily interfered with by VPN clients. It may be that some specific VPN clients don't get in the way, but experimentation may be necessary.

The fact that Android Auto contains code explicitly for warning about VPNs indicates this issue may not be simple.

Does wired Android Auto work with your VPN?

Carlito

de0u I have not tried wired Android Auto. However, I think I was able to solve the issue. In addition to whitelisting Android Auto in the VPN, I also turned off the kill switch. Once I did that, Android Auto immediately started working as intended.

I will write a separate post with the details of what I did, as I have seen a few others with this issue that may not have been resolved.

de0u

Carlito Thanks for reporting back!

Carlito

de0u You're welcome!