| Internet-Draft | DNS EDE option for rate-limited queries | February 2026 |
| Sivaraman | Expires 27 August 2026 | [Page] |
This memo documents an EDNS Extended DNS Errors INFO-CODE for conditions where truncated responses are returned because of rate-limiting by the nameserver.¶
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DNS nameservers return EDNS Extended DNS Errors options [RFC8914] in query responses to provide extra details about the result of DNS query processing.¶
When queries are rate-limited, e.g., due to the effect of DNS Response Rate Limiting [RRL] or client IP-address based rate limiting, nameservers may return truncated responses possibly with an empty answer section depending on the implementation. In such responses, nameservers MAY include a EDNS Extended DNS Error option with the INFO-CODE set to "Rate Limited" as provided in Section 4.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
There are no security considerations.¶
IANA is requested to allocate the following code point in the "Extended DNS Error Codes" registry in the "Domain Name System (DNS) Parameters" registry group.¶
| INFO-CODE | Purpose | Reference |
|---|---|---|
| TBD | Rate Limited | See Section 1. |