DNS 1 FORMERR vs 7 YXRRSET
Both DNS 1 (FORMERR) and 7 (YXRRSET) belong to the DNS Response Codes (RCODEs) category. 1 indicates that format error. The name server was unable to interpret the query due to a malformed DNS message. 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
Format error. The name server was unable to interpret the query due to a malformed DNS message.
何时出现
Your DNS client or library sent a query the server could not parse, often caused by a buggy resolver, corrupted packet, or unsupported EDNS options.
如何修复
Check your DNS client or library version for known bugs. Capture the raw query with dig or Wireshark and verify it conforms to the DNS wire format.
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 1: Format error. The name server was unable to interpret the query due to a malformed DNS message.
DNS 7: RR Set Exists when it should not. A resource record set exists that the update prerequisite says should not.
You encounter 1 when your DNS client or library sent a query the server could not parse, often caused by a buggy resolver, corrupted packet, or unsupported EDNS options.
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 1 (FORMERR): Check your DNS client or library version for known bugs. Capture the raw query with dig or Wireshark and verify it conforms to the DNS wire format. For 7 (YXRRSET): Delete the conflicting RRset before retrying the update, or adjust your prerequisite conditions to match the actual zone state.