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About this tool. The SOA record is the birth certificate of a DNS zone: which server is primary, who administers it, and a serial number that changes on every edit. Comparing serials is the classic way to spot stale secondary servers or confirm a change has published.
How to read your soa record lookup results
The SOA record holds the zone's primary nameserver, the responsible contact, a serial number, and the refresh and expiry timers.
The serial number should increase every time you change the zone. Secondary servers use it to know when to update.
Common problems and how to fix them
Secondary nameservers are out of date
Confirm the serial number increments on each change. If it does not, secondaries never pull the update.
Common questions.What is an SOA record?
The Start of Authority record. It defines administrative details for a DNS zone, including its serial number and timing values.
What is the SOA serial number?
A version counter for the zone. It must increase on every change so secondary servers know to refresh.