DNS Transport over TCP - Operational Requirements
draft-ietf-dnsop-dns-tcp-requirements-06
Domain Name System Operations J. Kristoff
Internet-Draft DePaul University
Updates: 1123 (if approved) D. Wessels
Intended status: Best Current Practice Verisign
Expires: November 7, 2020 May 6, 2020
DNS Transport over TCP - Operational Requirements
draft-ietf-dnsop-dns-tcp-requirements-06
Abstract
This document encourages the practice of permitting DNS messages to
be carried over TCP on the Internet. This includes both DNS over
unencrypted TCP, as well as over an encrypted TLS session. The
document also considers the consequences with this form of DNS
communication and the potential operational issues that can arise
when this best common practice is not upheld.
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 November 7, 2020.
Copyright Notice
Copyright (c) 2020 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
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to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
Kristoff & Wessels Expires November 7, 2020 [Page 1]
Internet-Draft DNS Transport over TCP May 2020
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Background . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Uneven Transport Usage and Preference . . . . . . . . . . 4
2.2. Waiting for Large Messages and Reliability . . . . . . . 5
2.3. EDNS0 . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.4. Fragmentation and Truncation . . . . . . . . . . . . . . 6
2.5. "Only Zone Transfers Use TCP" . . . . . . . . . . . . . . 7
3. DNS over TCP Requirements . . . . . . . . . . . . . . . . . . 7
4. Network and System Considerations . . . . . . . . . . . . . . 8
4.1. Connection Establishment and Admission . . . . . . . . . 8
4.2. Connection Management . . . . . . . . . . . . . . . . . . 9
4.3. Connection Termination . . . . . . . . . . . . . . . . . 10
4.4. DNS-over-TLS . . . . . . . . . . . . . . . . . . . . . . 11
5. DNS over TCP Filtering Risks . . . . . . . . . . . . . . . . 11
5.1. DNS Wedgie . . . . . . . . . . . . . . . . . . . . . . . 11
5.2. DNS Root Zone KSK Rollover . . . . . . . . . . . . . . . 12
6. Logging and Monitoring . . . . . . . . . . . . . . . . . . . 12
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
9. Security Considerations . . . . . . . . . . . . . . . . . . . 13
10. Privacy Considerations . . . . . . . . . . . . . . . . . . . 13
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.1. Normative References . . . . . . . . . . . . . . . . . . 14
11.2. Informative References . . . . . . . . . . . . . . . . . 14
Appendix A. Standards Related to DNS Transport over TCP . . . . 20
A.1. IETF RFC 1035 - DOMAIN NAMES - IMPLEMENTATION AND
SPECIFICATION . . . . . . . . . . . . . . . . . . . . . . 20
A.2. IETF RFC 1536 - Common DNS Implementation Errors and
Suggested Fixes . . . . . . . . . . . . . . . . . . . . . 21
A.3. IETF RFC 1995 - Incremental Zone Transfer in DNS . . . . 21
A.4. IETF RFC 1996 - A Mechanism for Prompt Notification of
Zone Changes (DNS NOTIFY) . . . . . . . . . . . . . . . . 21
A.5. IETF RFC 2181 - Clarifications to the DNS Specification . 21
A.6. IETF RFC 2694 - DNS extensions to Network Address
Translators (DNS_ALG) . . . . . . . . . . . . . . . . . . 21
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