Error when working with DotNet (Technitium) in Debian 12

[mdkberry]

Pre-Submit Checklist:

• Check applicable sources for existing issues:
  • Windows Known Issues
  • Linux Known Issues
  • Github Issues

What happened:

When Technitium is installed and running to use DNS over TTS (or any secure DNS service) Portmaster wont let some things work (so far, nslookup and syncthing are failing to resolve when Portmaster is on and Technitium is hosting the secure DNS but there may be other things) There are no clues in the "dropped traffic" screens on Portmaster though.

in Windows I resolved all issues by setting this for Technitium:

• disabled SPN for the Technitium app in Portmaster
• disabled Block Secure DNS bypassing for the Technitium app in Portmaster

In Debian I have DotNet not Technitium but setting the same as above did not resolve it like it did in Windows.

Additionally in Debian I had to set DNS servers to 127.0.0.1 and ::1 in the network card (wifi) for Technitium to work so it might be something to do with that clashing with Portmaster (detail of that in logs below)

What did you expect to happen?:

I expected portmaster to advise me not to use DotNet, but then to let it work when I changed the settings as per above. This was how it went on Windows 10 ,and shortly after worked fine there as far as I can tell. so I expected the same in Debian 12 but have had different issues (mentioned above).

How did you reproduce it?:

Start Technitium. Start Portmaster. Together they not happy. Stop Portmaster and everything works again.

Debug Information:

I didnt see any traffic being dropped at all inside portmaster, but Syncthing was no longer working to sync, and nslookup was failing with timeout there may be other issues. All this while Portsmaster was open and stops being an issue when it closes. DNS sites did resolve in browsers and pings, but were slow, so it was confusing, since some things were working.

I checked the Portmaster logs and saw entries like this: "Jun 07 16:28:32 dell-mb portmaster-start[775]: 240607 16:28:32.366 les/worker:109 ▶ ERRO 247 nameserver: service-worker dns resolver failed (28): listen udp 127.0.0.17:53: bind: address already in use - restarting in 56s"

[github-actions]

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