DNS 6 YXDOMAIN vs 18 BADTIME
Both DNS 6 (YXDOMAIN) and 18 (BADTIME) 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, 18 means that signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.
Description
Name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records.
Quand vous le voyez
A DNS UPDATE prerequisite check failed because the domain name already exists when the update expected it to be absent.
Comment résoudre
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.
Description
Signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.
Quand vous le voyez
The clocks on the DNS client and server are too far apart (usually more than 5 minutes), causing TSIG signature validation to fail.
Comment résoudre
Synchronize clocks on both machines using NTP. Check that the TSIG fudge value (allowed skew) is reasonable — the default 300 seconds is usually sufficient.
Différences clés
DNS 6: Name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records.
DNS 18: Signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.
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 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.
Quand utiliser lequel
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 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.