AdGuard cuts off network connection to Custom DNS on iOS

[Batman2814]

Please answer the following questions for yourself before submitting an issue

• Filters were updated before reproducing an issue
• I checked the knowledge base and found no answer
• I checked to make sure that this issue has not already been filed

AdGuard version

4.5.2

Environment

• OS: 17.3.1
• Device: iPhone 17 plus

Ad Blocking

No response

Privacy

No response

Social

No response

Annoyances

No response

Security

No response

Other

No response

Language-specific

No response

Advanced protection for Safari

• yes, I do

Which DNS server do you use?

Custom DNS

DNS protocol

DNS-over-QUIC

Custom DNS

AdGuard Private DNS

DNS filtering

• yes, I do

Custom DNS filter

Na

DNS implementation

AdGuard

Tunnel mode

Split-Tunnel

Low-level settings

Bootstrap server:
Fallback server:
Blocking mode, etc:

Issue Details

Steps to reproduce:

1. Have AdGuard Ablocker for IOS & AdGuard VPN for IOS enabled.
2. After so often the connection to private DNS cuts off and cuts of Network connection.
3. To get it working have to a least disable VPN and toggle wifi off the on again to refresh the connection.

Expected Behavior

Should not cut off connection to network

Actual Behavior

Network gets cut off.

Screenshots

No response

Additional Information

I will send the logs for this report.

[Batman2814]

Logs have been sent.

[Batman2814]

#2189

Might be related to this also.

[maxikuzmin]

@Batman2814 can you give more details? What dns are you using? How often does the internet connection break? Does the connection break just happen after some time, are there any additional steps to break the internet connection?

[Batman2814]

I'm using AdGuard Private DNS. Protocol QUIC. All I know is it happens either when I come back from it. It also might have happened when using it, too. I always have AdGuard VPN for iOS enabled. It always seems to happen after some time.

[maxikuzmin]

@Batman2814 could you please clarify, with other DNS's this problem does not recur? Have you tried changing the protocol or DNS?

[Batman2814]

Good day. I have not yet attempted to modify the protocol or DNS settings. Could you please advise if I should proceed with either of these actions? If so, kindly specify whether I should prioritize changing the protocol to TLS or switching to AdGuard Public DNS within the AdGuard Adblocker Pro application for iOS. Your guidance would be greatly appreciated.

[maxikuzmin]

@Batman2814 we need to understand first whether the problem is with the individual DNS (or DNS protocol) server or with the DNS partition as a whole. So I ask you to try to select a different DNS with QUIC protocol, and also try with a different DNS (DOH or DOT protocol). Perhaps the problem could also be in Private DNS.

I tried also reproducing this problem but it did not happen again for me, it would be nice to get your debug logs as well

[Batman2814]

I would be happy to test that out and get back to you about the issue. I did send debug logs in the email. Could you please let me know what happened to that log?

[Batman2814]

When I encountered the same issue once more while using AdGuard Private DNS on my Apple iPhone, I decided to toggle the Wi-Fi connection off and then back on. Surprisingly, this action prompted a sudden refresh, which successfully established a connection. Additionally, the most recent activity time was updated on the AdGuard Private DNS website within my account.

[maxikuzmin]

@Batman2814 we got your logs, I meant logs with other DNS. By the way what about other DNS? Have you tried to check this problem with other DNS? After your update, after restarting the WIFI connection, did the problem recur again?