I'm pretty sure basically every operating system under the sun uses the DNS servers communicated by the local DHCP server. Sure, for the vast majority of privat

I'm pretty sure basically every operating system under the sun uses the DNS servers communicated by the local DHCP server. Sure, for the vast majority of private users that may be the local ISP's DNS, and the DHCP server is on the router provided by said ISP, but if you configure cloudflare DNS servers there, Debian will use those. I think it's misguided to describe this as a quirk of Debian, and while there are good reasons not use the ISP DNS servers, you should change those in your router settings instead of the settings of every OS on every device you own. If you happen to plug in your device at your employer's network, for instance (not saying that's a good idea, but BYOD is a reality for some employees), there is a good chance you won't be able to access internal resources if you follow the author's advice.