Public DNS Services

We all know about the public DNS services offered by Google (8.8.8.8,
8.8.4.4) and Cloudflare (1.1.1.1, 1.0.0.1); did you know these
addresses have names as well? And of course there are IPv6 addresses to
go with the IPv4 ones.

Try this command to find out all the related Google DNS services:

    host -a dns.google.

(Yup, that’s “dns.google.”, no “.com” or anything else on the end.)
That’s quite a breathtaking list of entries.

For Cloudflare, try

    host one.one.one.one.

Note that the “-a” option (“tell me everything”) doesn’t work with
Cloudflare; quite a few online services are now imposing restrictions
on these “all info” lookups, but clearly not Google, at least not on
this domain: obviously they want it to remain easy for people to
discover the services they’re offering.