BIND

More information on DLZ

To use DLZ (Dynamically Loadable Zones) in Bind
​https://nlnet.nl/project/bind-dlz/200205-sane/paper.html

Updating the root.hints file with dig

Instead of downloading ​https://www.internic.net/domain/named.root, you can run:

dig @a.root-servers.net  .  ns > db.cache
grep '^\.\|^[a-z]' db.cache | sort >/srv/named/etc/namedb/root.hints

That will give you a file very close to the BLFS example. Sanitized so no leading spaces are introduced.

Verifying the tarball using gpg

You may want to verify the validity of the downloaded files from isc instead of trusting the MD5 from the book.
Run these commands if you have gpg installed:

wget https://www.isc.org/docs/isc-keyblock.asc
gpg --import isc-keyblock.asc
wget https://downloads.isc.org/isc/bind9/<version>/bind-<version>.tar.xz{,.asc}
gpg --verify bind-<version>.tar.xz.asc