DNS 0 NOERROR vs 2 SERVFAIL
Both DNS 0 (NOERROR) and 2 (SERVFAIL) belong to the DNS Response Codes (RCODEs) category. 0 indicates that no error condition. The query completed successfully and the response contains the requested data. Meanwhile, 2 means that server failure. The name server encountered an internal error while processing the query.
Descripción
No error condition. The query completed successfully and the response contains the requested data.
Cuándo lo verás
This is the normal, successful response to any DNS query — the name was resolved and the answer section contains the requested records.
Cómo solucionarlo
No fix needed. RCODE 0 means the DNS lookup succeeded as expected.
Descripción
Server failure. The name server encountered an internal error while processing the query.
Cuándo lo verás
The recursive resolver could not get an authoritative answer — commonly caused by DNSSEC validation failures, unreachable upstream nameservers, or misconfigured zones.
Cómo solucionarlo
Try a different resolver (e.g., 8.8.8.8 or 1.1.1.1) to isolate the issue. If you control the zone, check DNSSEC signatures, SOA serial consistency, and nameserver reachability.
Diferencias clave
DNS 0: No error condition. The query completed successfully and the response contains the requested data.
DNS 2: Server failure. The name server encountered an internal error while processing the query.
You encounter 0 when this is the normal, successful response to any DNS query — the name was resolved and the answer section contains the requested records.
You encounter 2 when the recursive resolver could not get an authoritative answer — commonly caused by DNSSEC validation failures, unreachable upstream nameservers, or misconfigured zones.
Cuándo usar cada uno
For 0 (NOERROR): No fix needed. RCODE 0 means the DNS lookup succeeded as expected. For 2 (SERVFAIL): Try a different resolver (e.g., 8.8.8.8 or 1.1.1.1) to isolate the issue. If you control the zone, check DNSSEC signatures, SOA serial consistency, and nameserver reachability.