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SOA Record Checker
Fetch SOA records to review name server, contact, serial, refresh, retry, and expiry values for a zone, useful for DNS change audits and propagation checks.
How to use this tool
- Enter the zone domain and run an SOA query.
- Review primary host, contact, serial, and zone timing parameters.
- Export response data when auditing publication and secondary sync behavior.
What to validate
- Serial increments for every zone publication event.
- Refresh/retry values that control secondary polling behavior.
- Expire and minimum values that affect data staleness and caching.
Operational guidance
- Use a consistent serial strategy to simplify incident timelines.
- Tune timing values conservatively to avoid unnecessary zone transfer load.
- Lower high TTL settings ahead of planned migration windows when needed.
FAQ
- Why can a secondary still serve old data after serial updates?
- Secondaries only poll on refresh/retry schedules unless manually triggered, so updated serials are not always picked up immediately.
- What happens if serial numbers decrease?
- Secondaries reject lower serials and continue serving prior zone data, so serials should always increase.
- How should expire be chosen?
- Expire should balance resilience and staleness tolerance, defining how long a secondary may serve data without primary contact.
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