What is SOA record?

The Start of Authority record with a zone's primary server, admin contact and timers.

The SOA record holds the zone's serial number and refresh, retry, expire and negative-cache timers. The serial changes whenever the zone is edited, which makes it a cheap change detector.

Related terms

• NS record: A DNS record naming the authoritative name servers for a domain.
• CAA record: A DNS record that lists which certificate authorities may issue certificates for a domain.
• TTL (time to live): How long, in seconds, resolvers may cache a DNS answer.