dig - DNS Lookup Utility
The dig is a powerful CLI to find out information about domains and IP addresses without using any 3rd party tools or websites.
01. What is the website’s IP address?
dig apple.com02. How do you identify the name servers(NS) associated with a domain?
dig NS apple.com +short
dig NS com. +short03. Which eMail Servers(MX) are responsible for a domain?
dig MX apple.com +short04. Finding out the domain name associated with the IP address (reverse IP lookup)
dig -x 1.1.1.1 +short
dig -x 8.8.4.4 +short05. Finding out the delegation path for any DNS zone (learn how DNS works)
dig apple.com +trace06. Finding out DNS answers from specific cache resolver (e.g. Cloudflare [1.1.1.1], Google DNS [8.8.8.8], IBM and so on for cyberciti.biz domain)
dig A cyberciti.biz @1.1.1.1 +short
dig A cyberciti.biz @8.8.8.8 +short07. Finding out the cache expire time (TTL) for DNS
# AAAA is for IPv6
dig A www.cyberciti.biz +nocmd +noall +answer +ttlid
dig AAAA www.cyberciti.biz +nocmd +noall +answer +ttlid08. Finding if a zone is synchronized with all authoritative name servers (look for serial number)
dig nixcraft.com +nssearch09. What is my public IPv4 or IPv6 address?
dig TXT o-o.myaddr.l.google.com @ns1.google.com +short
dig TXT ch whoami.cloudflare @1.0.0.1 +short10. Getting help about the dig command
man dig11. Finding out the IP address associated the domain name.
dig yahoo.com +short | sort -V