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NS record

NS

NS records name the servers that are authoritative for a zone — the ones that hold the real answers.

Check this on a domain with DNS Lookup →

01.

What an NS record does

NS records name the authoritative servers for a zone. A resolver working down from the root follows NS records at each level until it reaches the servers that hold the zone itself.

Every zone has NS records at its apex, and they cannot be removed. A zone without them is not delegated to anything.

02.

Delegation and the parent zone

Two sets of NS records exist for any delegated domain: the set in the parent zone, published by the registry, and the set in the zone itself. The parent set is what resolvers actually follow.

Changing nameservers means changing the parent set through your registrar. Editing NS records inside the old zone changes nothing that resolvers use to find you.

Resolving a namewww.example.com · A
0 of 4

Illustrative. A resolver with an empty cache walks down from the root, and each answer is only a referral until the zone's own nameserver replies. Every hop is cached for its TTL, which is why the second lookup is one question, not four.
03.

When the two sets disagree

A mismatch between the parent delegation and the zone's own NS records is a common cause of intermittent, hard-to-reproduce resolution problems, because the answer depends on which server a resolver happens to ask.

Persistent disagreement between resolvers long after a TTL has expired usually points here rather than at caching.

Two NS sets, one zoneparent delegation · zone apex

Parent (registrar) says

Zone apex says

Illustrative names. The parent zone's delegation says where to go; the child zone's own NS records say who is authoritative. When they disagree, resolvers can land on servers that no longer carry the zone.

Related records

SOA recordHolds administrative parameters for a zone.A recordMaps a hostname to an IPv4 address.DNSSECSigns DNS answers so resolvers can detect tampering.