DNS 5 REFUSED vs 8 NXRRSET
Both DNS 5 (REFUSED) and 8 (NXRRSET) belong to the DNS Response Codes (RCODEs) category. 5 indicates that query refused. The name server refuses to perform the requested operation for policy reasons. Meanwhile, 8 means that rR Set that should exist does not. A required resource record set is missing from the zone.
Description
Query refused. The name server refuses to perform the requested operation for policy reasons.
When You See It
The server rejected your query due to access control — for example, a recursive resolver that only serves its own network, or a zone transfer blocked by ACL.
How to Fix
Check the server's allow-query, allow-recursion, or allow-transfer ACLs. If you are not authorized to use this resolver, switch to a public DNS service.
Description
RR Set that should exist does not. A required resource record set is missing from the zone.
When You See It
A DNS UPDATE prerequisite expected a certain RRset to exist (e.g., an MX record), but the zone does not contain it.
How to Fix
Create the missing RRset in the zone before retrying the update, or change the prerequisite to not require its existence.
Key Differences
DNS 5: Query refused. The name server refuses to perform the requested operation for policy reasons.
DNS 8: RR Set that should exist does not. A required resource record set is missing from the zone.
You encounter 5 when the server rejected your query due to access control — for example, a recursive resolver that only serves its own network, or a zone transfer blocked by ACL.
You encounter 8 when a DNS UPDATE prerequisite expected a certain RRset to exist (e.g., an MX record), but the zone does not contain it.
When to Use Which
For 5 (REFUSED): Check the server's allow-query, allow-recursion, or allow-transfer ACLs. If you are not authorized to use this resolver, switch to a public DNS service. For 8 (NXRRSET): Create the missing RRset in the zone before retrying the update, or change the prerequisite to not require its existence.