What's in a zone file?

• Entries are called "Resource Records"

• Authoritative information

  • ns.example.com. IN A 192.168.2.1

• Name servers responsible for domain

  • example.com. IN NS ns.example.com.
  • Called "delegation" by technical community.

• Glue records

  • ns.example.com. IN A 192.168.2.1 - but this time, in parent zone!
  • Without these, you'd have to ask ns.example.com for its own address.

• TLD zones: Typically just NS records and glue.