Apple Services not available when connected to VPN with Custom DoH/DoT DNS

When a device is connected to VPN using NEPacketTunnelProvider, and configured with encrypted custom DNS (NEDNSOverHTTPSSettings), some Apple Services (e.g. Siri) are unavailable. The same configuration but with clear text custom DNS (NEDNSSettings) works as expected.

Inspecting network traffic while using Siri revealed SSL shutdown packets and TCP termination packets.

Device: iOS 14.4.2
Network Extension APIs: NEPacketTunnelProvider, NEPacketTunnelNetworkSettings, NEDNSOverHTTPSSettings

Attachments:



Answered by Systems Engineer in 669953022
I would open a bug report here and include these logs as well as a pcap. Please respond back with the Feedback ID.


Matt Eaton
DTS Engineering, CoreOS
meaton3@apple.com
Accepted Answer
I would open a bug report here and include these logs as well as a pcap. Please respond back with the Feedback ID.


Matt Eaton
DTS Engineering, CoreOS
meaton3@apple.com
Hi Matt, thanks for the quick response!
Report is submitted, ID: 9072905
No problem. I see you bug report internally and it looks like it has landed in the right spot.


Matt Eaton
DTS Engineering, CoreOS
meaton3@apple.com

Hi!

From what I can see, the issue is still not fixed. Is there any info about this one?

Tested in iOS & iPadOS 15.2 Beta 4.

AFAIK Siri has never worked with encrypted DNS since iOS 14 introduced the feature. I can also confirm same behavior with macOS 12.6 today.

Is Apple going to do anything about this? We're talking about a critical issue for VPN providers.

Apple Services not available when connected to VPN with Custom DoH/DoT DNS
 
 
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