Internet Engineering Task Force M. Sivaraman Internet-Draft Banu Systems Private Limited Intended status: Experimental 25 February 2026 Expires: 29 August 2026 DNS EDE option for rate-limited queries draft-muks-dns-ede-rate-limited-02 Abstract This memo documents EDNS Extended DNS Errors INFO-CODE values for rate-limited and over-quota conditions. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 29 August 2026. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Sivaraman Expires 29 August 2026 [Page 1] Internet-Draft DNS EDE option for rate-limited queries February 2026 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. "Rate Limited" EDE INFO-CODE . . . . . . . . . . . . . . . . 2 3. "Over Quota" EDE INFO-CODE . . . . . . . . . . . . . . . . . 2 4. Requirements notation . . . . . . . . . . . . . . . . . . . . 2 5. Security considerations . . . . . . . . . . . . . . . . . . . 3 6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 3 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 3 7.1. Normative references . . . . . . . . . . . . . . . . . . 3 7.2. Informative references . . . . . . . . . . . . . . . . . 3 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction DNS nameservers return EDNS Extended DNS Errors options [RFC8914] in query responses to provide extra details about the result of DNS query processing. This memo documents EDNS Extended DNS Errors INFO- CODE values to be returned when rate-limiting is performed, or an over-quota condition is reached. 2. "Rate Limited" EDE INFO-CODE When DNS queries or transactions 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 RCODE=REFUSED or return truncated responses possibly with an empty answer section depending on the implementation. In such responses, nameservers MAY include an EDNS Extended DNS Error option with the INFO-CODE set to "Rate Limited" as provided in Section 6. 3. "Over Quota" EDE INFO-CODE When DNS queries or transactions cause an over-quota condition such as when the count of DNS UPDATEs allowed for a customer have breached a limit, nameservers may return failures. In such responses, nameservers MAY include an EDNS Extended DNS Error option with the INFO-CODE set to "Over Quota" as provided in Section 6. 4. Requirements notation 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. Sivaraman Expires 29 August 2026 [Page 2] Internet-Draft DNS EDE option for rate-limited queries February 2026 5. Security considerations There are no security considerations. 6. IANA considerations IANA has allocated the following code points in the "Extended DNS Error Codes" registry in the "Domain Name System (DNS) Parameters" registry group. +===========+==============+================+ | INFO-CODE | Purpose | Reference | +===========+==============+================+ | 31 | Rate Limited | See Section 2. | +-----------+--------------+----------------+ | 32 | Over Quota | See Section 3. | +-----------+--------------+----------------+ Table 1 7. References 7.1. Normative references [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8914] Kumari, W., Hunt, E., Arends, R., Hardaker, W., and D. Lawrence, "Extended DNS Errors", RFC 8914, DOI 10.17487/RFC8914, October 2020, . 7.2. Informative references [RRL] Vixie, P. and V. Schryver, "DNS Response Rate Limiting (DNS RRL)", 2012, . Author's Address Sivaraman Expires 29 August 2026 [Page 3] Internet-Draft DNS EDE option for rate-limited queries February 2026 Mukund Sivaraman Banu Systems Private Limited 6001 Beach Road, #19-09, Golden Mile Tower SINGAPORE 199589 Singapore Email: muks@banu.com URI: https://banu.com/ Sivaraman Expires 29 August 2026 [Page 4]