DNS 3 NXDOMAIN vs 5 REFUSED
Both DNS 3 (NXDOMAIN) and 5 (REFUSED) belong to the DNS Response Codes (RCODEs) category. 3 indicates that non-Existent Domain. The queried domain name does not exist in the DNS namespace. Meanwhile, 5 means that query refused. The name server refuses to perform the requested operation for policy reasons.
Descrição
Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
Quando você o vê
The domain has no DNS records at all — either it was never registered, has expired, or you have a typo in the hostname.
Como corrigir
Double-check the domain spelling. If you own the domain, verify your registrar settings and ensure the nameservers are correctly delegated.
Descrição
Query refused. The name server refuses to perform the requested operation for policy reasons.
Quando você o vê
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.
Como corrigir
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.
Diferenças principais
DNS 3: Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
DNS 5: Query refused. The name server refuses to perform the requested operation for policy reasons.
You encounter 3 when the domain has no DNS records at all — either it was never registered, has expired, or you have a typo in the hostname.
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.
Quando usar qual
For 3 (NXDOMAIN): Double-check the domain spelling. If you own the domain, verify your registrar settings and ensure the nameservers are correctly delegated. 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.