https://wiki.debian.org/Bind9
https://intodns.com/
https://dnsviz.net/d/bdcom.com/dnssec/
bind.tar.gz
https://www.youtube.com/watch?v=1xkp8pLDqn0
https://github.com/shamimrezasohag/DSAT-DNSSecurityAnalysisTool
https://www.vedbex.com/subdomain-finder