DNS tool

NS Record Checker

Compare authoritative nameserver records returned by public DNS resolvers.

Record type

What this check shows

NS records identify the authoritative nameservers responsible for a DNS zone. They are central to provider migrations and delegation troubleshooting.

Comparing recursive answers helps reveal stale delegations, old provider nameservers and zones where authoritative servers do not agree.

When to use it

  • DNS provider migrations
  • Nameserver delegation changes
  • Diagnosing intermittent resolution
  • Confirming removal of old nameservers

How to read the result

  • The parent-zone delegation and the NS records published inside the child zone should be consistent.
  • Every listed nameserver should be reachable and authoritative for the zone.
  • Different NS sets may indicate cached delegation data or a configuration mismatch.

Questions

Why do parent and child NS records matter?

Resolvers learn the delegation from the parent but can also cache NS data from the child zone; mismatches can produce inconsistent behavior.

Do nameserver changes propagate instantly?

No. Parent delegation and recursive caches have TTLs that can keep previous nameservers visible.

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