🛠 DNSSpy Monitor, validate and verify your DNS configurations https://dnsspy.io/

🛠 https://github.com/farrokhi/dnsdiag dnsdiag - is a DNS diagnostics and performance measurement tools.

🛠 https://github.com/mschwager/fierce fierce - is a DNS reconnaissance tool for locating non-contiguous IP space.

🛠 https://github.com/google/namebench namebench - provides personalized DNS server recommendations based on your browsing history.

🛠 https://github.com/blechschmidt/massdns massdns - is a high-performance DNS stub resolver for bulk lookups and reconnaissance.