DNS not switching to backup

[Peteruk1]

The problem

Two DNS servers on Home-Assistant
192.168.53.2
and backup
192.168.53.4

It seems checkonline.home-assistant.io will switch to to my backup DNS when I fail first but not apigw.tuyaeu.com and just keeps trying 192.168.53.2 and not switch over to 192.168.53.4 in order to control devices.

Can this be looked into thanks

What version of Home Assistant Core has the issue?

core-2025.4.1

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant Core

Integration causing the issue

No response

Link to integration documentation on our website

No response

Diagnostics information

No response

Example YAML snippet

Anything in the logs that might be useful for us?

Additional information

No response

[mib1185]

sorry, but i don't get it - which integration or add-on or "part of the program" you mean?
Further you're using the core installation method, so you're responsible for any host related configuration, since HA runs just as a python program on your host system - ha doesn't have any own dns configuration in this setup.

[Peteruk1]

So HA has a DHCP client it pulls DNS from the router HA is setup with a Preferred and Alternative DNS when a fail Preferred by firewall I want HA to switch to Alternative problem is it stays on Preferred when it gets no answer.

However testing again it switched over maybe a rebooted of HA was needed as I had DHCP lease with 3 minutes and added the new DNS which HA pulled but maybe did not fully update will the new DNS?

[mib1185]

just to be sure - which installation method are you using?

[Peteruk1]

VirtualBox