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SOA Record Lookup

SOA defines zone authority and update timing; serial increments when zone content changes.

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Frequently Asked Questions

What is a DNS SOA record?
The Start of Authority record defines the primary nameserver for a zone, the responsible mailbox, the serial number, and timers for refresh, retry, expire, and minimum TTL.
What does the SOA serial mean?
It is a version number for the zone. Many operators use a YYYYMMDDnn format; others use an incrementing or Unix time value. It should increase when the zone changes.
Why do refresh and retry matter?
Secondary nameservers use refresh to know when to check for updates and retry when a refresh fails. These values affect how quickly changes propagate between authorities.
What is the responsible email (RNAME)?
RNAME encodes the mailbox of the zone administrator using dots. The first dot represents the @ in the email address and escaped dots are preserved.
Why are SOA serials mismatched across nameservers?
A lagging secondary or transfer failure can leave different serials on different authorities. Once transfers succeed, serials should match.