NS Lookup

NS (Name Server) records identify which DNS servers are authoritative for a domain — meaning they hold the official DNS records for that domain. When a DNS resolver needs to look up a domain, it queries the NS records to find the authoritative nameservers, then queries those servers directly for the specific record. NS records are set at your domain registrar and typically point to your DNS hosting provider.

RFC 1035 requires a minimum of two NS records for redundancy. Most domains have two to four nameservers. If a single nameserver goes down, resolvers automatically try the others. Using nameservers in different geographic locations and operated by different providers adds resilience. Having only one nameserver is a single point of failure — if it goes offline, your entire domain becomes unreachable.

NS records stored in DNS may differ from your registrar's records if a nameserver change was recently made and has not yet propagated, if the domain is using DNS hosting separate from registration, or if there is a glue record mismatch. After changing nameservers, allow 24–48 hours for full propagation. The registrar's records are the source of truth — DNS records update as propagation completes.

A glue record is an A record stored at the parent zone (the TLD) that provides the IP address of a nameserver whose hostname is within the same domain. For example, if ns1.example.com is a nameserver for example.com, a chicken-and-egg problem occurs: to resolve ns1.example.com you need to already know where example.com is hosted. The glue record breaks this cycle by providing ns1.example.com's IP address directly in the TLD zone.