SOA record
The start-of-authority record at the top of every DNS zone, holding the primary nameserver, the administrator's address, a serial number and timing values.
What it means
Every zone has exactly one SOA record, at its apex. Its fields: MNAME (the primary nameserver), RNAME (the administrator's mailbox, with the @ written as a dot), SERIAL (incremented on each change so secondary servers copy the zone), REFRESH, RETRY and EXPIRE (timers for secondaries), and MINIMUM.
MINIMUM has been redefined over time. RFC 2308 made it, together with the SOA record's own TTL, the bound on how long resolvers cache negative answers such as NXDOMAIN. A high value means a record you just created can stay invisible to resolvers that recently asked for it and got nothing.
An SOA lookup is a quick way to see which provider is authoritative for a domain.
Example
example.com. 3600 IN SOA ns1.dnshost.example. hostmaster.example.com. 2026102101 7200 3600 1209600 3600Related terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
All 432 terms in the glossaryThe wiki: blocklists and bounce codes