DNS 8 NXRRSET vs 22 BADTRUNC
Both DNS 8 (NXRRSET) and 22 (BADTRUNC) belong to the DNS Response Codes (RCODEs) category. 8 indicates that rR Set that should exist does not. A required resource record set is missing from the zone. Meanwhile, 22 means that bad truncation. The TSIG record was truncated in a way that makes it impossible to verify the message signature.
Descripción
RR Set that should exist does not. A required resource record set is missing from the zone.
Cuándo lo verás
A DNS UPDATE prerequisite expected a certain RRset to exist (e.g., an MX record), but the zone does not contain it.
Cómo solucionarlo
Create the missing RRset in the zone before retrying the update, or change the prerequisite to not require its existence.
Descripción
Bad truncation. The TSIG record was truncated in a way that makes it impossible to verify the message signature.
Cuándo lo verás
A large DNS response was truncated (TC bit set) but the TSIG MAC was computed over the full message, making the truncated version unverifiable.
Cómo solucionarlo
Retry the query over TCP to avoid truncation. If using UDP, ensure your EDNS buffer size is large enough to receive the full signed response.
Diferencias clave
DNS 8: RR Set that should exist does not. A required resource record set is missing from the zone.
DNS 22: Bad truncation. The TSIG record was truncated in a way that makes it impossible to verify the message signature.
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.
You encounter 22 when a large DNS response was truncated (TC bit set) but the TSIG MAC was computed over the full message, making the truncated version unverifiable.
Cuándo usar cada uno
For 8 (NXRRSET): Create the missing RRset in the zone before retrying the update, or change the prerequisite to not require its existence. For 22 (BADTRUNC): Retry the query over TCP to avoid truncation. If using UDP, ensure your EDNS buffer size is large enough to receive the full signed response.