NS records define the authoritative name servers for a domain. They are central to DNS delegation and tell resolvers where to fetch authoritative answers. An NS lookup helps verify that your domain is delegated to the correct provider and that the name servers match the registrar settings.
Common NS issues include mismatched registrar and zone NS records, missing glue records for in-zone name servers, or stale NS entries after a migration. These mistakes can make a domain appear partially broken or unreachable. Use this lookup to confirm the published NS set and validate that all servers respond.
If you need related checks, try SOA record DNS lookup and Check DNSSEC lookup online.
They must match. If they differ, resolvers may follow the registrar delegation and ignore the zone NS records. Always update both when migrating DNS.
Glue records are A or AAAA records for in-zone name servers. Without glue, resolvers may not reach the authoritative servers during lookup.
Two is the minimum. Many providers use four or more for resilience. Ensure all listed servers are operational.
Yes. You can delegate a subdomain by adding NS records for that subdomain and configuring the authoritative zone at the target name servers.
Propagation delays or caching can cause differences. Verify the authoritative zone and allow TTL to expire after changes.
Indirectly. If NS records are wrong, all DNS answers can be affected, including A and MX records.