Primary, secondary e NOTIFY

Primary, secondary, and NOTIFY

An authoritative zone can be served by multiple servers. A primary is the source from which changes are made or distributed; a secondary receives a copy, often through zone transfer. Both can answer authoritatively. “Primary” and “secondary” describe how zone data is managed, not whether a server is authoritative.

The SOA serial helps secondaries decide whether their copy is current. NOTIFY is an alert that a zone may have changed; it does not carry the whole zone. The secondary checks the serial and transfers data if needed. Keep parent delegation and the NS data served by the child consistent, and monitor that every secondary has loaded the expected serial.

References: RFC 1996 — DNS NOTIFY · RFC 9199 — operational considerations

Check your understanding

Choose the best answer. The examples use training names and do not send real DNS queries.

Quiz#dns.m11.l1.e1

Which statement is correct?

A secondary is never authoritativeBoth primary and secondary can serve authoritative answersNOTIFY contains the entire new zone