NS Record — Nameserver

What is an NS record

An NS record defines which nameservers are authoritative for a domain. All other DNS records (A, MX, TXT, etc.) are stored on those nameservers. When a resolver looks up information about example.com, the chain of trust leads it here.

Example

example.com.  IN  NS  ns1.example-dns.com.
example.com.  IN  NS  ns2.example-dns.com.

Two NS records tell the resolver: "you can query either one — both will give you the same answer." In practice, resolvers usually pick one at random and fall back to the other on failure.

How many NS records do I need?

At a minimum 2 NS. Best practice is 3–4, on different networks/locations, so that if one data center goes down your domain remains accessible. Major DNS providers (Cloudflare, AWS Route 53, Google Cloud DNS) provide 4 NS across different geographic regions.

NS at the registrar vs at the nameservers

There are two places where NS records are defined:

• At the registrar (parent delegation): you declare "these are my nameservers." This is the most important — this is where the chain begins.
• At the nameservers themselves (zone NS records): these must match the delegation.

If these two don't agree, your domain will still work but many diagnostic tools will report warnings. The Διαγνωστικό DNS checks exactly this.

Glue records

If your nameservers are within the same domain (e.g. ns1.example.com for example.com), a circular dependency arises: to find the NS records of example.com you need to ask the NS servers of example.com. This is resolved with glue records: the TLD registry also provides the IP addresses of the nameservers alongside the delegation, breaking the circular dependency.