Simple DNS subdomain enumeration.
docker build -t go_gues_dns
docker run -it --rm --name go_guess_dns go_guess_dns
go build .
go run . -wordlist 100names.txt -domain <domain.A>
https://github.com/danielmiessler/SecLists
ns3.google.com 216.239.36.10
mail.google.com 142.251.40.165
Built from the book: Black Hat Go