DNS 3 NXDOMAIN vs 18 BADTIME
Both DNS 3 (NXDOMAIN) and 18 (BADTIME) 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, 18 means that signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.
Descripción
Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
Cuándo lo verás
The domain has no DNS records at all — either it was never registered, has expired, or you have a typo in the hostname.
Cómo solucionarlo
Double-check the domain spelling. If you own the domain, verify your registrar settings and ensure the nameservers are correctly delegated.
Descripción
Signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.
Cuándo lo verás
The clocks on the DNS client and server are too far apart (usually more than 5 minutes), causing TSIG signature validation to fail.
Cómo solucionarlo
Synchronize clocks on both machines using NTP. Check that the TSIG fudge value (allowed skew) is reasonable — the default 300 seconds is usually sufficient.
Diferencias clave
DNS 3: Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
DNS 18: Signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.
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 18 when the clocks on the DNS client and server are too far apart (usually more than 5 minutes), causing TSIG signature validation to fail.
Cuándo usar cada uno
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 18 (BADTIME): Synchronize clocks on both machines using NTP. Check that the TSIG fudge value (allowed skew) is reasonable — the default 300 seconds is usually sufficient.