DNS Transport over TCP - Implementation Requirements (RFC7766)
Original Publication Date: 2016-Mar-01
Included in the Prior Art Database: 2016-Mar-04
Internet Society Requests For Comment (RFCs)
J. Dickinson: AUTHOR [+5]
Most DNS [RFC1034] transactions take place over UDP [RFC768]. TCP [RFC793] is always used for full zone transfers (using AXFR) and is often used for messages whose sizes exceed the DNS protocol's original 512-byte limit. The growing deployment of DNS Security (DNSSEC) and IPv6 has increased response sizes and therefore the use of TCP. The need for increased TCP use has also been driven by the protection it provides against address spoofing and therefore exploitation of DNS in reflection/amplification attacks. It is now widely used in Response Rate Limiting [RRL1] [RRL2]. Additionally, recent work on DNS privacy solutions such as [DNS-over-TLS] is another motivation to revisit DNS-over-TCP requirements.
Internet Engineering Task Force (IETF) J. Dickinson Request for Comments: 7766 S. Dickinson Obsoletes: 5966 Sinodun Updates: 1035, 1123 R. Bellis Category: Standards Track ISC ISSN: 2070-1721 A. Mankin D. Wessels Verisign Labs March 2016
DNS Transport over TCP - Implementation Requirements
This document specifies the requirement for support of TCP as a transport protocol for DNS implementations and provides guidelines towards DNS-over-TCP performance on par with that of DNS-over-UDP. This document obsoletes RFC 5966 and therefore updates RFC 1035 and RFC 1123.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7766.
al. Standards Track [Page 1]
RFC 7766 DNS over TCP March 2016
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