NS record lookup: check nameserver DNS records
TL;DR. NS records list the authoritative name servers for a zone. Every zone has at least one NS at its apex and exactly the same NS set at the parent delegation point.
How the NS record works
If the apex NS set and the parent delegation NS set disagree, you have lame delegation. Some resolvers will eventually pick up the apex set, others will keep using the parent set until the parent zone is updated. An NS record check across global resolvers exposes exactly which resolvers still point at the old nameservers after a registrar change.
Example NS record
example.com. 86400 IN NS a.iana-servers.net.Check a NS record live
Run the multi-resolver probe → and confirm propagation of your NS record across 12 global resolvers in real time.
Reference
Spec: RFC 1035.
NS record FAQ
How do I check NS records? →
Run a probe in dnsprobe and we query the NS records from 12 global resolvers, so you can confirm a nameserver change has propagated everywhere after moving DNS providers.
How long do nameserver changes take? →
Nameserver (NS) changes at the registrar are bounded by the parent zone TTL, often 24-48 hours for TLDs. A global NS check tells you when every resolver has switched to the new nameservers.
What is lame delegation? →
Lame delegation is when the NS records at the parent (registrar) disagree with the NS records published in your own zone, or point at a server that is not authoritative. It causes intermittent resolution failures.