This article explains why a registrar may return an ERROR: 118 Inconsistent set of NS RRs message when registering or updating a domain that uses UltraDNS name servers. This usually occurs when the registry allows fewer authoritative name servers than the full UltraDNS name server set configured in the zone.
Symptoms
The registrar or registry returns an error similar to the following when you try to update the domain registration:
ERROR: 118 Inconsistent set of NS RRs (IP, NS host names) (/2610:a1:1016:0:0:0:0:1, [pdns1.ultradns.net, pdns6.ultradns.co.uk, pdns2.ultradns.net, pdns5.ultradns.info, pdns3.ultradns.org, pdns4.ultradns.org]) /Code: 319)
Why This Happens
Some registries and country code top level domains restrict how many authoritative name servers can be used in the domain registration. UltraDNS zones may contain six authoritative name server hostnames, such as pdns1 through pdns6. If the registry only allows four or five name servers, submitting all six name servers can cause the registrar update to fail.
This can also fail if the registrar submits fewer name servers, but the registry checks the UltraDNS zone and sees a different NS record set. In that case, the registry detects an inconsistency between the name servers in the parent registration and the NS records in the zone.
How to Resolve the Error
- Confirm the maximum number of authoritative name servers allowed by the registrar or registry for the affected domain.
- In the UltraDNS zone, remove enough UltraDNS NS records so the zone contains only the number of name servers allowed by the registry.
- If the registry limit is four name servers, use the remaining UltraDNS name servers, typically
pdns1throughpdns4. - Submit the same UltraDNS name server hostnames at the registrar.
- Confirm that the registrar delegation and the NS records in the UltraDNS zone match.
Example
If the zone currently contains pdns1 through pdns6, but the registry only allows four name servers, remove pdns5 and pdns6 from the zone. Then submit only pdns1, pdns2, pdns3, and pdns4 at the registrar.
Expected Outcome
The registrar update should succeed once the parent registration and the UltraDNS zone contain a consistent name server set that complies with the registry limit.
Important Notes
- The exact name server limit is controlled by the registrar or registry, not UltraDNS.
- Do not submit more UltraDNS name servers than the registry allows.
- Do not leave extra UltraDNS NS records in the zone if the registry performs a consistency check against the zone file.
- If the registry allows five name servers instead of four, only remove enough NS records to meet that limit.