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A nameserver inside the domain has no glue record

MediumConfirmeddns.health.glue-missing

What this check looks for

One of your nameservers lives inside the domain it serves, and the registry does not hold its address. To find the address a resolver must ask the nameserver — which it cannot find without the address.

Why it matters

This is a circular dependency, and whether it works depends entirely on what a resolver happens to have cached. Fresh resolvers fail outright; ones with a warm cache succeed, which is why the problem is so often reported as intermittent.

When the check passes, your report says: “The registry holds glue for every nameserver inside the domain”.

What it costs your score

When this check fails it removes 8 points from your DNS score, before the status, confidence and repeat multipliers are applied. DNS carries a weight of 10 in the overall score.

It shares the dns.health.delegation family ceiling of 35 points: however many findings that family produces, together they cannot remove more than that from DNS. One underlying problem showing up in several places is still one problem.

Severity
medium
Default confidence
confirmed
Status when triggered
warn
Deduction
8 points
Family cap
dns.health.delegation · 35
Category
DNS
Module
Dns health
Fix owned by
registrar
In the ruleset since
2026.09

How the whole score is calculated

How to fix it

Register the nameserver's address as a glue record at your registrar.

Without glue, a resolver with a cold cache cannot resolve your domain at all.

  1. Find the "register a nameserver" / "host records" / "private nameservers" section of your registrar's control panel.

  2. Register each in-domain nameserver name with its IPv4 and IPv6 address.

  3. Alternatively, avoid the problem entirely by using nameserver names outside this domain — a managed DNS provider's names need no glue.

  4. Allow up to a day for the registry to publish the change.

How to confirm it worked

  • dig +norecurse @<tld-nameserver> NS ‹domain› — expect the additional section to carry the nameserver's address

A named slot like ‹domain› — and the braces left in the configuration below — is filled in with your own values when this rule appears on a report.

Technical detail

These nameservers are inside ‹domain› and the parent sent no glue address for them: ‹server list›. RFC 1034 §4.2.1 requires the parent to publish glue A/AAAA records for any nameserver inside the zone it delegates. Glue is entered at the registrar, not in your zone file — it is usually called "register a nameserver", "host records", or "private nameservers" in a registrar's control panel.

Standards and references

Test this on your domain

Run the check that produces this finding, on its own, against any domain.

Open the dns health checker

Other dns health checks