Free tool
Nameserver check.
Detect nameserver drift between your registrar and zone. Identify NS mismatches, delegation issues, and stealth nameserver problems.
What are nameservers?
Nameservers are the servers that hold your DNS records and answer queries about your domain. Your registrar delegates your domain to specific nameservers, and those nameservers serve your zone file (A records, MX records, TXT records, etc.).
Registrar vs. zone NS
Your registrar stores the NS records that point the world to your nameservers (the "glue" records). Your zone file also contains NS records. These two sets must match — when they don't, you have NS drift.
Why drift is dangerous
NS drift can cause intermittent DNS resolution failures, split-brain scenarios where different resolvers see different records, and can leave your domain vulnerable to hijacking if stale NS entries point to servers you no longer control.
Common causes
NS drift happens when you migrate DNS providers (e.g., from GoDaddy to Cloudflare) and forget to update one set of NS records, or when someone edits the zone NS records without updating the registrar.
What to check
Check
Severity
Details
Registrar NS matches zone NS
High
Both must point to the same set of nameservers
All NS servers are responsive
High
Each NS should respond to queries with consistent answers
NS hostnames resolve
Critical
NS records must point to hostnames that have A/AAAA records
Consistent SOA serial
Medium
All NS servers should serve the same SOA serial number
Related tools
Monitor NS changes
DNS Doctors detects NS drift and alerts you when registrar and zone NS records diverge.
Learn more