DNS 3 NXDOMAIN vs 7 YXRRSET
Both DNS 3 (NXDOMAIN) and 7 (YXRRSET) 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, 7 means that rR Set Exists when it should not. A resource record set exists that the update prerequisite says should not.
描述
Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
何时出现
The domain has no DNS records at all — either it was never registered, has expired, or you have a typo in the hostname.
如何修复
Double-check the domain spelling. If you own the domain, verify your registrar settings and ensure the nameservers are correctly delegated.
描述
RR Set Exists when it should not. A resource record set exists that the update prerequisite says should not.
何时出现
A DNS UPDATE failed because a specific RRset (e.g., an A record) already exists when the prerequisite required it to be absent.
如何修复
Delete the conflicting RRset before retrying the update, or adjust your prerequisite conditions to match the actual zone state.
主要区别
DNS 3: Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
DNS 7: RR Set Exists when it should not. A resource record set exists that the update prerequisite says should not.
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 7 when a DNS UPDATE failed because a specific RRset (e.g., an A record) already exists when the prerequisite required it to be absent.
何时使用哪个
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 7 (YXRRSET): Delete the conflicting RRset before retrying the update, or adjust your prerequisite conditions to match the actual zone state.