DNS Zone Transfer Protocol (AXFR)
RFC 5936

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 14

Internet Engineering Task Force (IETF)                          E. Lewis
Request for Comments: 5936                                 NeuStar, Inc.
Updates: 1034, 1035                                       A. Hoenes, Ed.
Category: Standards Track                                         TR-Sys
ISSN: 2070-1721                                                June 2010

                   DNS Zone Transfer Protocol (AXFR)

Abstract

   The standard means within the Domain Name System protocol for
   maintaining coherence among a zone's authoritative name servers
   consists of three mechanisms.  Authoritative Transfer (AXFR) is one
   of the mechanisms and is defined in RFC 1034 and RFC 1035.

   The definition of AXFR has proven insufficient in detail, thereby
   forcing implementations intended to be compliant to make assumptions,
   impeding interoperability.  Yet today we have a satisfactory set of
   implementations that do interoperate.  This document is a new
   definition of AXFR -- new in the sense that it records an accurate
   definition of an interoperable AXFR mechanism.

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/rfc5936.

Lewis & Hoenes               Standards Track                    [Page 1]
RFC 5936            DNS Zone Transfer Protocol (AXFR)          June 2010

Copyright Notice

   Copyright (c) 2010 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
   (http://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
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

Lewis & Hoenes               Standards Track                    [Page 2]
RFC 5936            DNS Zone Transfer Protocol (AXFR)          June 2010

Table of Contents

   1. Introduction ....................................................4
      1.1. Definition of Terms ........................................4
      1.2. Scope ......................................................5
      1.3. Context ....................................................5
      1.4. Coverage and Relationship to Original AXFR Specification ...5
   2. AXFR Messages ...................................................6
      2.1. AXFR Query .................................................8
           2.1.1. Header Values .......................................8
           2.1.2. Question Section ...................................10
           2.1.3. Answer Section .....................................10
           2.1.4. Authority Section ..................................10
           2.1.5. Additional Section .................................10
      2.2. AXFR Response .............................................11
           2.2.1. Header Values ......................................12
           2.2.2. Question Section ...................................14
           2.2.3. Answer Section .....................................14
           2.2.4. Authority Section ..................................14
           2.2.5. Additional Section .................................14
      2.3. TCP Connection Aborts .....................................15
   3. Zone Contents ..................................................15
      3.1. Records to Include ........................................15
      3.2. Delegation Records ........................................16