Most organizations hate DNS and hate to see it done properly. That is why they buy enterprise DNS management kludge and do not allow correct hierarchical subdomains.

Once did run a proper DNS server. Unfortunately I left my original notes from 2006 back with the people for whom I managed it. Here are some minor note on the topic.

  • A = IPv4 address record

  • AAAA = IPv6 address record

  • CNAME = Canonical Name, basically an alias. DNS continues trying the lookup with the new name.

  • DNAME = Like CNAME but alias for entire domains and subdomains.

  • PTR = Pointer record. Like CNAME but processing stops. SOA = Start of Authority. Where to find the most true information.

  • MX = mail exchange

  • TXT = Could be a message for humans. Could be something else.

  • NS = nameserver record, points to a different resource for finding

  • subdomains names for this domain.

  • SSHFP = SSH host key fingerprints to help with this problem.

  • SPF = Sender policy framework - OBSOLETE