DNS 1 FORMERR vs 6 YXDOMAIN
Both DNS 1 (FORMERR) and 6 (YXDOMAIN) belong to the DNS Response Codes (RCODEs) category. 1 indicates that format error. The name server was unable to interpret the query due to a malformed DNS message. Meanwhile, 6 means that name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records.
Descripción
Format error. The name server was unable to interpret the query due to a malformed DNS message.
Cuándo lo verás
Your DNS client or library sent a query the server could not parse, often caused by a buggy resolver, corrupted packet, or unsupported EDNS options.
Cómo solucionarlo
Check your DNS client or library version for known bugs. Capture the raw query with dig or Wireshark and verify it conforms to the DNS wire format.
Descripción
Name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records.
Cuándo lo verás
A DNS UPDATE prerequisite check failed because the domain name already exists when the update expected it to be absent.
Cómo solucionarlo
Review your dynamic update prerequisites. If you expect to create a new name, remove the existing records first or change the prerequisite to allow existing names.
Diferencias clave
DNS 1: Format error. The name server was unable to interpret the query due to a malformed DNS message.
DNS 6: Name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records.
You encounter 1 when your DNS client or library sent a query the server could not parse, often caused by a buggy resolver, corrupted packet, or unsupported EDNS options.
You encounter 6 when a DNS UPDATE prerequisite check failed because the domain name already exists when the update expected it to be absent.
Cuándo usar cada uno
For 1 (FORMERR): Check your DNS client or library version for known bugs. Capture the raw query with dig or Wireshark and verify it conforms to the DNS wire format. For 6 (YXDOMAIN): Review your dynamic update prerequisites. If you expect to create a new name, remove the existing records first or change the prerequisite to allow existing names.