DNS 3 NXDOMAIN vs 9 NOTAUTH
Both DNS 3 (NXDOMAIN) and 9 (NOTAUTH) belong to the DNS Response Codes (RCODEs) category. 3 indicates that non-Existent Domain. The queried domain name does not exist in the DNS namespace. 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
Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
When You See It
The domain has no DNS records at all — either it was never registered, has expired, or you have a typo in the hostname.
How to Fix
Double-check the domain spelling. If you own the domain, verify your registrar settings and ensure the nameservers are correctly delegated.
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 3: Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
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 3 when the domain has no DNS records at all — either it was never registered, has expired, or you have a typo in the hostname.
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 3 (NXDOMAIN): Double-check the domain spelling. If you own the domain, verify your registrar settings and ensure the nameservers are correctly delegated. 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.