Can anyone advise or provide working script or solution to make DNS flush on each reboot?
Also it will be great to make this happen each day at 0:00.
Why it is important?
https://protonvpn.com/blog/how-to-flush-dns/
Your DNS cache is effectively a list of visited websites, much like your browser history. However, the DNS cache is usually managed by your device’s operating system and is therefore outside the scope of any single browser — and the safeguards browsers usually implement.
One such safeguard is incognito (or private) mode. While incognito mode doesn’t deliver on the vast majority of its advertised privacy promises, it does prevent your browser from storing your browsing history. Yet, a very similar list of websites is present inside the DNS cache and outlives your incognito session. A compromised device could therefore expose your browsing history via the DNS cache, even if you visited those websites in incognito mode.
Caching generally occurs in your client device or software more so than in the router. As @admon stated, I am not aware of the default DNS resolver in the gl device caching results itself out of the box. If you install something like Adguard on it, that might change things a little. But your article snippet you posted even says this is on your device’s OS, not the networking equipment.
So, are you looking for help about managing your software or OS caching or are you looking for help with your router?
Dns caches store your device, not a router.
Router listen dns resolver server to look domain instead IP addresses. Adguard Home is dns resolver server with filter domains from upstream another dns resolver severs.
