RFC 2136 (rfc2136) - Page 1 of 26

Dynamic Updates in the Domain Name System (DNS UPDATE)

Network Working Group                                  P. Vixie, Editor
Request for Comments: 2136                                          ISC
Updates: 1035                                                S. Thomson
Category: Standards Track                                      Bellcore
                                                             Y. Rekhter
                                                                  Cisco
                                                               J. Bound
                                                                    DEC
                                                             April 1997

         Dynamic Updates in the Domain Name System (DNS UPDATE)

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Abstract

   The Domain Name System was originally designed to support queries of
   a statically configured database.  While the data was expected to
   change, the frequency of those changes was expected to be fairly low,
   and all updates were made as external edits to a zone's Master File.

   Using this specification of the UPDATE opcode, it is possible to add
   or delete RRs or RRsets from a specified zone.  Prerequisites are
   specified separately from update operations, and can specify a
   dependency upon either the previous existence or nonexistence of an
   RRset, or the existence of a single RR.

   UPDATE is atomic, i.e., all prerequisites must be satisfied or else
   no update operations will take place.  There are no data dependent
   error conditions defined after the prerequisites have been met.

1 - Definitions

   This document intentionally gives more definition to the roles of
   "Master," "Slave," and "Primary Master" servers, and their
   enumeration in NS RRs, and the SOA MNAME field.  In that sense, the
   following server type definitions can be considered an addendum to
   [RFC 1035], and are intended to be consistent with [RFC 1996]:

      Slave           an authoritative server that uses AXFR or IXFR to
                      retrieve the zone and is named in the zone's NS
                      RRset.



Vixie, et. al.              Standards Track