I just set up a local DNS server in my LAN with a custom domain “jellyfin.local”. I set my router up to advertise this DNS server via DHCP. This seems to work for my Linux laptop. But neither my windows machine nor my android phone use my local DNS server.

I believe the issue may be that my router is crappy, and while it does announce my DNS server correctly for IPv4, I am unable to stop it from announcing some other DNS server for IPv6. I believe that this may confuse my Windows and Android devices, which probably prioritise DNS via IPv6, and hence use the wrong DNS server.

I could now buy a better router. But before I do that, I wanted to know if someone else successfully uses a local DNS server with Windows devices, Android devices, Smart TVs, and so on. Specifically, with a properly configured DHCP server, will all modern devices use the correct DNS server?

Update

Thanks for all the informative comments! I have now resorted to using a global DNS record (jellyfin.mydomain.de) to point to my local server. That seems to work and the easiest option.