Network Working Group P. Spacek Internet-Draft CZ.NIC Intended status: Standards Track O. Gudmundsson Expires: September 20, 2018 Cloudflare O. Sury ISC March 19, 2018 Minimal EDNS compliance requirements draft-spacek-edns-camel-diet-00 Abstract DNS responders must either follow RFC 6891 by implementing EDNS or respond with RCODE=FORMERR to queries containing OPT record. Non- compliant implementations are not worth talking to. 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 September 20, 2018. Copyright Notice Copyright (c) 2018 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 Simplified BSD License text as described in Section 4.e of Spacek, et al. Expires September 20, 2018 [Page 1] Internet-Draft Minimal EDNS compliance March 2018 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2 2. The Protocol . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Security Considerations . . . . . . . . . . . . . . . . . . . 2 4. Privacy Considerations . . . . . . . . . . . . . . . . . . . 2 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 6. Normative References . . . . . . . . . . . . . . . . . . . . 3 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction EDNS version 0 was standardized in 1999, but non-RFC 1035 compliant implementations still exist and cause lot of extra queries and complicated logic in recursive resolvers. RFC 6891 clearly states that FORMERR is the only acceptable answer for implementations without support for EDNS. The cost of supporting these non-compliant implementations keeps increasing. 1.1. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. 2. The Protocol No DNS response message to a repeated DNS query containing EDNS extension means that the other side is not a DNS responder and the querier MUST NOT retry its query without EDNS. 3. Security Considerations Instruction to follow EDNS standard does not change security properties beyond what is written in RFC 6891. 4. Privacy Considerations This has no effect on privacy of DNS. Spacek, et al. Expires September 20, 2018 [Page 2] Internet-Draft Minimal EDNS compliance March 2018 5. IANA Considerations [Note to IANA, to be removed prior to publication: there are no IANA considerations stated in this version of the document.] 6. Normative References [RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, November 1987, . [RFC2671] Vixie, P., "Extension Mechanisms for DNS (EDNS0)", RFC 2671, DOI 10.17487/RFC2671, August 1999, . [RFC6891] Damas, J., Graff, M., and P. Vixie, "Extension Mechanisms for DNS (EDNS(0))", STD 75, RFC 6891, DOI 10.17487/RFC6891, April 2013, . Authors' Addresses Petr Spacek Email: petr.spacek@nic.cz Olafur Gudmundsson Email: olafur+ietf@cloudflare.com Ondrej Sury Email: ondrej@isc.org Spacek, et al. Expires September 20, 2018 [Page 3]