📄 SOA Record Checker

What you'll see

• Primary master host, responsible email contact, and full timing parameters.
• Serial numbers so you can confirm zone publishes and detect stale secondaries.
• Authority responses clarifying which server supplied the SOA details.

Common use cases

• Monitor serial increments during DNS updates or automation runs.
• Fine-tune refresh and retry intervals for secondary name servers.
• Troubleshoot negative caching behaviour when records appear out-of-date.

Troubleshooting tips

• Increment the serial number with every zone publish—many admins use YYYYMMDD## formats for clarity.
• Refresh and retry values influence how quickly secondary servers pick up changes, so adjust conservatively.
• If the minimum TTL is extremely high, reduce it temporarily before planned DNS migrations.

FAQ

Why hasn't my secondary server updated even after increasing the serial?

Check the refresh and retry intervals—secondaries wait until the refresh timer expires before pulling updates. You can also trigger an AXFR manually if needed.

What happens if I roll the serial number backward?

Secondaries ignore lower serials, so they will continue serving stale data. Always increment the serial when publishing a new zone file.

How should I choose the expire timer?

Expire defines how long a secondary will serve data without contacting the primary. Shorter periods ensure stale data ages out quickly but require highly available primaries.