Full-tunnel not working when automatically switching between IPv6 networks

[Eugene-Savenko]

Issue Details

Reported by 1542905:

Home wifi network and my company has ipv6 connection. When I choose full-tunnel mode and switch wifi network from home to company, vpn does not work to solve dns. So I had to turn off the wifi and turn it back on before the vpn would work again.

The error does not occur when 2 switch wifi networks have no IPv6 connection. And switch wifi network manually.

• AdGuard version:
  AdGuard Pro v. 2.1.2.173
• Device model and storage size:
• Operating system and version:
  12.4.1

Expected Behavior

AdGuard continues resolving all DNS requests

Actual Behavior

AdGuard DNS only resolves domain names with ipv6

Steps to reproduce

1. Turn on full-tunnel mode
2. Turn on “restart when network change” in Advenced settings
3. Connect to wifi network with ipv6 enabled
4. Move to another WiFi network (with IPv6 enabled), let IOS connect automatically
5. VPN not solve dns

Additional info

Logs are in CRM, user 1542905.

[SoLenny]

@Eugene-Savenko Hello, can you please reproduce it on free version of AdGuard?

[bigdargon]

@SoLenny I will check the free version with Adguard DNS

[SoLenny]

@bigdargon Okay, thank you.
Waiting for it so.

[bigdargon]

@SoLenny Adguard Free has the same error as Adguard Pro. I sent the log with ID 1542905.

I noticed that, when switching networks with IPv6 connection in Full-tunnel mode, the application's VPN will default to using IPv6 to resolve without using IPv4 at all. Some websites with IPv6 addresses will still be accessible, while websites with only IPv4 addresses will not.

When manually turning off and on wifi network, VPN will switch back to using IPv4 as default and normal access.

[ameshkov]

Assigned to v3.2, than kyou!

[bigdargon]

@ameshkov I hope the Pro version will update too!

[ameshkov]

Yeah, some time after v3.2 we'll finally synchronize both apps.

[IvanIin]

@Eugene-Savenko @bigdargon
could you check if the bug is reproducing on ios13?

[bigdargon]

@IvanIin Tested in the free version and pro on ios 13 have the same error

[ameshkov]

@bigdargon could you please check v4.0 beta version?

[bigdargon]

@ameshkov I will check it out soon

[bigdargon]

@ameshkov Tested. The bug does not affect in version 4.0 beta. You can close it. Thank you!