A nameserver (name server) is a DNS server designated as the authoritative source for a domain's DNS records. When DNS resolvers need to look up records for a domain, they ultimately query the domain's nameservers for the definitive answer.
Authoritative vs Recursive Nameservers
- Authoritative nameserver — Holds the actual DNS zone file for a domain. It gives definitive "this is the correct record" answers. Your domain registrar or DNS provider (Cloudflare, Route 53) runs these.
- Recursive resolver — Your ISP's or public DNS server (8.8.8.8, 1.1.1.1) that queries on your behalf, following the chain from root servers down to authoritative servers. It caches results.
Changing Nameservers
To move DNS management to a new provider (e.g. migrating to Cloudflare):
- Sign up with the new DNS provider and set up your DNS records there.
- Get the new provider's nameserver addresses (e.g.
ava.ns.cloudflare.com,bob.ns.cloudflare.com). - Log in to your domain registrar and replace the existing NS records.
- Wait for propagation (up to 48 hours).
Why Two or More Nameservers?
Redundancy. If one nameserver is unavailable, others answer DNS queries. DNS requires a minimum of two nameservers per zone. Most providers offer at least four, distributed globally.
Key Point
After changing nameservers, all DNS records must be managed at the new provider. Records at the old provider are ignored once the NS change propagates.