DNS 6 YXDOMAIN vs 16 BADVERS/BADSIG
Both DNS 6 (YXDOMAIN) and 16 (BADVERS/BADSIG) belong to the DNS Response Codes (RCODEs) category. 6 indicates that name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records. Meanwhile, 16 means that bad OPT Version or TSIG Signature Failure. Either the EDNS version in the OPT record is not supported, or the TSIG signature on the message failed verification.
Описание
Name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records.
Когда вы это видите
A DNS UPDATE prerequisite check failed because the domain name already exists when the update expected it to be absent.
Как исправить
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.
Описание
Bad OPT Version or TSIG Signature Failure. Either the EDNS version in the OPT record is not supported, or the TSIG signature on the message failed verification.
Когда вы это видите
As BADVERS: your client sent an EDNS version higher than the server supports. As BADSIG: the TSIG MAC on the message did not match, indicating a shared-secret mismatch or message tampering.
Как исправить
For BADVERS, downgrade the EDNS version (most servers support version 0 only). For BADSIG, regenerate and re-synchronize the TSIG shared secret on both endpoints.
Ключевые различия
DNS 6: Name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records.
DNS 16: Bad OPT Version or TSIG Signature Failure. Either the EDNS version in the OPT record is not supported, or the TSIG signature on the message failed verification.
You encounter 6 when a DNS UPDATE prerequisite check failed because the domain name already exists when the update expected it to be absent.
You encounter 16 when as BADVERS: your client sent an EDNS version higher than the server supports. As BADSIG: the TSIG MAC on the message did not match, indicating a shared-secret mismatch or message tampering.
Когда что использовать
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. For 16 (BADVERS/BADSIG): For BADVERS, downgrade the EDNS version (most servers support version 0 only). For BADSIG, regenerate and re-synchronize the TSIG shared secret on both endpoints.