NS Lookup

What does the tool return?

A table of Nameserver and TTL, one row per NS record the resolver gives for the exact name you typed, plus a "Nameservers found" count. Trailing dots are removed from the host names. Nothing else is shown: no IP addresses for the servers, no SOA data and no check of whether each server actually answers.

Why does a subdomain say "No NS records found"?

NS records exist where a zone starts. In most setups www.example.com or blog.example.com sits inside the zone of example.com and has no NS records of its own, so the lookup is empty. Only a subdomain that has been delegated to other nameservers returns NS records. To find who serves a subdomain’s DNS, look up the parent domain instead.

How do I tell which DNS provider hosts a domain?

Read the host names. Cloudflare’s end in ns.cloudflare.com, Amazon Route 53 uses names containing awsdns, and GoDaddy’s default nameservers are under domaincontrol.com. A registrar’s own nameservers often mean DNS is managed at the registrar. The hosts tell you where the zone is edited, which may differ from where the domain is registered.

Are these the same nameservers set at my registrar?

They should be, but this tool cannot confirm it. A domain’s nameservers are set at the registrar and published by the registry in the parent zone (.com and so on), and the zone itself also lists NS records. Depending on the resolver and what it has cached, the answer may come from either copy. A mismatch between the two sets, a common cause of intermittent failures after a provider switch, is not detected here.

I changed nameservers but still see the old ones. Why?

The delegation is cached by resolvers according to the TTL, and the one shown here is a counted-down value from Cloudflare’s resolver. Delegation records at the top level often carry long TTLs, so a change can take hours to a day or more to be seen everywhere. Check the TTL column to see how much longer the old answer can last.

What should I do about DNSSEC when switching providers?

If the domain is DNSSEC-signed, the DS record at the registrar refers to the old provider’s key. Moving nameservers without removing or replacing that DS record can make the domain fail validation. This tool does not show DS or DNSSEC status, so check that at your registrar before the switch.

How many nameservers should a domain have?

Providers usually assign two or more so that DNS keeps working if one server is down, and often spread them over different networks. The count shown is only what is published; this tool does not judge whether the number is adequate.