A lot of recursive servers can be bootstrapped with a entire root zone, which content is public here: https://www.iana.org/domains/root/files https://www.iana.o

A lot of recursive servers can be bootstrapped with a entire root zone, which content is public here: https://www.iana.org/domains/root/files https://www.iana.org/domains/root/files Recursive servers do not need public root servers because you could run a root yourself at 127.0.0.99 and point recursive to it, or bootstrap recursive one with this data. Of course, you need full control of the recursive server to set it up this way. Taking down all public root servers (all 1723 of them, according to public data) may have no impact on a properly set up recursive servers, because root zone is public and you can host it yourself.