Nameserver Mismatch Diagnosis

Problem

You are sure the DNS records exist, but lookups still return unexpected values or only work from some networks.

Symptoms

• DNS responses do not match the records you believe are configured.
• Some resolvers return the expected answer while others return old or empty data.
• Problems started after changing DNS hosting or moving the domain.

Top 3 Causes

1. Registrar delegation does not match the active DNS host - The domain still points to old nameservers.
2. The old zone is still answering - Previous provider infrastructure still has stale records.
3. Nameserver changes are still propagating - Recursive resolvers cache old delegation data during the transition window.

Diagnose with DechoNet

• RDAP / WHOIS to inspect the nameservers currently registered for the domain.
• DNS Lookup to compare NS records and live answers against what you expect.
• DNS Propagation Check to see whether resolver responses still differ globally.

Resolution Checklist

• Verify that registrar nameservers match the DNS provider that should serve the zone.
• Remove or update stale zones left behind at the previous DNS provider.
• If nameservers were recently changed, compare multiple public resolvers until delegation stabilizes.
• Re-check SOA serials and critical service records after any zone migration.
• Confirm that production records, not just test records, now resolve consistently.

When to Escalate

• Contact the registrar if nameserver changes are not reflected at the registration level.
• Contact the DNS hosting provider if delegation is correct but authoritative answers remain inconsistent or stale.