Separate EDNS version and response codes
03OPT reuses its TTL-shaped field for extended response code, EDNS version, and flags.
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“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
DIAGRAM§ 6.1.3 ↗
RFC 6891 · § 6.1.3EXAMPLE
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03
Return BADVERS rather than interpreting the data as a normal TTL.
Return BADVERS rather than interpreting the data as a normal TTL.
Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
Read the updated RFC section ↗
These bits do not mean an ordinary record-cache TTL.
- These bits do not mean an ordinary record-cache TTL.
- Unsupported EDNS versions use BADVERS with the responder’s supported version.
The drawing is a simplified worked example. Follow the linked RFC and its updates for implementation requirements.
Read the RFC section ↗Diagrams simplify the RFC. Read the linked sections for complete requirements.
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