DNS 6 YXDOMAIN vs 9 NOTAUTH
Both DNS 6 (YXDOMAIN) and 9 (NOTAUTH) 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, 9 means that server Not Authoritative for zone, or Not Authorized. The server is not authoritative for the zone named in the Zone section.
Description
Name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records.
When You See It
A DNS UPDATE prerequisite check failed because the domain name already exists when the update expected it to be absent.
How to Fix
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
Server Not Authoritative for zone, or Not Authorized. The server is not authoritative for the zone named in the Zone section.
When You See It
You sent a dynamic update or zone operation to a server that is not the authoritative master for that zone, or the server rejected it due to TSIG authentication failure.
How to Fix
Send the update to the correct primary authoritative server for the zone. If using TSIG, verify the key name and secret match on both client and server.
Key Differences
DNS 6: Name Exists when it should not. Used in dynamic updates to indicate a name that should not exist already has records.
DNS 9: Server Not Authoritative for zone, or Not Authorized. The server is not authoritative for the zone named in the Zone section.
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 9 when you sent a dynamic update or zone operation to a server that is not the authoritative master for that zone, or the server rejected it due to TSIG authentication failure.
When to Use Which
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 9 (NOTAUTH): Send the update to the correct primary authoritative server for the zone. If using TSIG, verify the key name and secret match on both client and server.