Network Working Group                                      S. Hollenbeck
Request for Comments: 4932                                VeriSign, Inc.
Obsoletes: 3732                                                 May 2007
Category: Standards Track


          Extensible Provisioning Protocol (EPP) Host Mapping

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.

Copyright Notice

   Copyright (C) The IETF Trust (2007).

Abstract

   This document describes an Extensible Provisioning Protocol (EPP)
   mapping for the provisioning and management of Internet host names
   stored in a shared central repository.  Specified in XML, the mapping
   defines EPP command syntax and semantics as applied to host names.
   This document obsoletes RFC 3732.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Relationship of Host Objects and Domain Objects  . . . . .  3
     1.2.  Conventions Used in This Document  . . . . . . . . . . . .  4
   2.  Object Attributes  . . . . . . . . . . . . . . . . . . . . . .  4
     2.1.  Host Names . . . . . . . . . . . . . . . . . . . . . . . .  4
     2.2.  Client Identifiers . . . . . . . . . . . . . . . . . . . .  4
     2.3.  Status Values  . . . . . . . . . . . . . . . . . . . . . .  4
     2.4.  Dates and Times  . . . . . . . . . . . . . . . . . . . . .  6
     2.5.  IP Addresses . . . . . . . . . . . . . . . . . . . . . . .  6
   3.  EPP Command Mapping  . . . . . . . . . . . . . . . . . . . . .  7
     3.1.  EPP Query Commands . . . . . . . . . . . . . . . . . . . .  7
       3.1.1.  EPP <check> Command  . . . . . . . . . . . . . . . . .  7
       3.1.2.  EPP <info> Command . . . . . . . . . . . . . . . . . .  9
       3.1.3.  EPP <transfer> Query Command . . . . . . . . . . . . . 11
     3.2.  EPP Transform Commands . . . . . . . . . . . . . . . . . . 11
       3.2.1.  EPP <create> Command . . . . . . . . . . . . . . . . . 12
       3.2.2.  EPP <delete> Command . . . . . . . . . . . . . . . . . 13
       3.2.3.  EPP <renew> Command  . . . . . . . . . . . . . . . . . 15
       3.2.4.  EPP <transfer> Command . . . . . . . . . . . . . . . . 15
       3.2.5.  EPP <update> Command . . . . . . . . . . . . . . . . . 15
     3.3.  Offline Review of Requested Actions  . . . . . . . . . . . 17
   4.  Formal Syntax  . . . . . . . . . . . . . . . . . . . . . . . . 19
   5.  Internationalization Considerations  . . . . . . . . . . . . . 24
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 25
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 25
   8.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 26
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 26
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 26
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 27
   Appendix A.  Changes from RFC 3732 . . . . . . . . . . . . . . . . 28

1.  Introduction

   This document describes an Internet host name mapping for version 1.0
   of the Extensible Provisioning Protocol (EPP).  This mapping is
   specified using the Extensible Markup Language (XML) 1.0 as described
   in [W3C.REC-xml-20040204] and XML Schema notation as described in
   [W3C.REC-xmlschema-1-20041028] and [W3C.REC-xmlschema-2-20041028].
   This document obsoletes RFC 3732 [RFC3732].

   [RFC4930] provides a complete description of EPP command and response
   structures.  A thorough understanding of the base protocol
   specification is necessary to understand the mapping described in
   this document.

   XML is case sensitive.  Unless stated otherwise, XML specifications
   and examples provided in this document MUST be interpreted in the
   character case presented to develop a conforming implementation.

1.1.  Relationship of Host Objects and Domain Objects

   This document assumes that host name objects have a subordinate
   relationship to a superordinate domain name object.  For example,
   host name "ns1.example.com" has a subordinate relationship to domain
   name "example.com".  EPP actions (such as object transfers) that do
   not preserve this relationship MUST be explicitly disallowed.

   A host name object can be created in a repository for which no
   superordinate domain name object exists.  For example, host name
   "ns1.example.com" can be created in the ".example" repository so that
   DNS domains in ".example" can be delegated to the host.  Such hosts
   are described as "external" hosts in this specification since the
   name of the host does not belong to the name space of the repository
   in which the host is being used for delegation purposes.

   Whether a host is external or internal relates to the repository in
   which the host is being used for delegation purposes.  Whether or not
   an internal host is subordinate relates to a domain within the
   repository.  For example, host ns1.example1.com is a subordinate host
   of domain example1.com, but it is not a subordinate host of domain
   example2.com. ns1.example1.com can be used as a name server for
   example2.com.  In this case, ns1.example1.com MUST be treated as an
   internal host, subject to the rules governing operations on
   subordinate hosts within the same repository.

1.2.  Conventions Used in This Document

   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 [RFC2119].

   In examples, "C:" represents lines sent by a protocol client and "S:"
   represents lines returned by a protocol server.  Indentation and
   white space in examples are provided only to illustrate element
   relationships and are not a REQUIRED feature of this protocol.

2.  Object Attributes

   An EPP host object has attributes and associated values that can be
   viewed and modified by the sponsoring client or the server.  This
   section describes each attribute type in detail.  The formal syntax
   for the attribute values described here can be found in the "Formal
   Syntax" section of this document and in the appropriate normative
   references.

2.1.  Host Names

   The syntax for host names described in this document MUST conform to
   [RFC0952] as updated by [RFC1123].  At the time of this writing, RFC
   3490 [RFC3490] describes a standard to use certain ASCII name labels
   to represent non-ASCII name labels.  These conformance requirements
   might change in the future as a result of progressing work in
   developing standards for internationalized host names.

2.2.  Client Identifiers

   All EPP clients are identified by a server-unique identifier.  Client
   identifiers conform to the "clIDType" syntax described in [RFC4930].

2.3.  Status Values

   A host object MUST always have at least one associated status value.
   Status values MAY be set only by the client that sponsors a host
   object and by the server on which the object resides.  A client can
   change the status of a host object using the EPP <update> command.
   Each status value MAY be accompanied by a string of human-readable
   text that describes the rationale for the status applied to the
   object.

   A client MUST NOT alter status values set by the server.  A server
   MAY alter or override status values set by a client subject to local
   server policies.  The status of an object MAY change as a result of
   either a client-initiated transform command or an action performed by
   a server operator.

   Status values that can be added or removed by a client are prefixed
   with "client".  Corresponding status values that can be added or
   removed by a server are prefixed with "server".  Status values that
   do not begin with either "client" or "server" are server-managed.

   Status Value Descriptions:

   -  clientDeleteProhibited, serverDeleteProhibited

      Requests to delete the object MUST be rejected.

   -  clientUpdateProhibited, serverUpdateProhibited

      Requests to update the object (other than to remove this status)
      MUST be rejected.

   -  linked

      The host object has at least one active association with another
      object, such as a domain object.  Servers SHOULD provide services
      to determine existing object associations.

   -  ok

      This is the normal status value for an object that has no pending
      operations or prohibitions.  This value is set and removed by the
      server as other status values are added or removed.

   -  pendingCreate, pendingDelete, pendingTransfer, pendingUpdate

      A transform command has been processed for the object (or in the
      case of a <transfer> command, for the host object's superordinate
      domain object), but the action has not been completed by the
      server.  Server operators can delay action completion for a
      variety of reasons, such as to allow for human review or third-
      party action.  A transform command that is processed, but whose
      requested action is pending, is noted with response code 1001.

   When the requested action has been completed, the pendingCreate,
   pendingDelete, pendingTransfer, or pendingUpdate status value MUST be
   removed.  All clients involved in the transaction MUST be notified
   using a service message that the action has been completed and that
   the status of the object has changed.

   "ok" status MAY only be combined with "linked" status.

   "linked" status MAY be combined with any status.

   "pendingDelete" status MUST NOT be combined with either
   "clientDeleteProhibited" or "serverDeleteProhibited" status.

   "pendingUpdate" status MUST NOT be combined with either
   "clientUpdateProhibited" or "serverUpdateProhibited" status.

   The pendingCreate, pendingDelete, pendingTransfer, and pendingUpdate
   status values MUST NOT be combined with each other.

   Other status combinations not expressly prohibited MAY be used.

2.4.  Dates and Times

   Date and time attribute values MUST be represented in Universal
   Coordinated Time (UTC) using the Gregorian calendar.  The extended
   date-time form using upper case "T" and "Z" characters defined in
   [W3C.REC-xmlschema-2-20041028] MUST be used to represent date-time
   values as XML Schema does not support truncated date-time forms or
   lower case "T" and "Z" characters.

2.5.  IP Addresses

   The syntax for IPv4 addresses described in this document MUST conform
   to [RFC0791].  The syntax for IPv6 addresses described in this
   document MUST conform to [RFC4291].  Practical considerations for
   publishing IPv6 address information in zone files are documented in
   [RFC1886], [RFC2874], and [RFC3152].  A server MAY reject IP
   addresses that have not been allocated for public use by IANA.  When
   a host object is provisioned for use as a DNS name server, IP
   addresses SHOULD be required only as needed to generate DNS glue
   records.

3.  EPP Command Mapping

   A detailed description of the EPP syntax and semantics can be found
   in [RFC4930].  The command mappings described here are specifically
   for use in provisioning and managing Internet host names via EPP.

3.1.  EPP Query Commands

   EPP provides two commands to retrieve host information: <check> to
   determine if a host object can be provisioned within a repository,
   and <info> to retrieve detailed information associated with a host
   object.

3.1.1.  EPP <check> Command

   The EPP <check> command is used to determine if an object can be
   provisioned within a repository.  It provides a hint that allows a
   client to anticipate the success or failure of provisioning an object
   using the <create> command as object provisioning requirements are
   ultimately a matter of server policy.

   In addition to the standard EPP command elements, the <check> command
   MUST contain a <host:check> element that identifies the host
   namespace.  The <host:check> element contains the following child
   elements:

   -  One or more <host:name> elements that contain the fully qualified
      names of the host objects to be queried.

   Example <check> command:

   C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:  <command>
   C:    <check>
   C:      <host:check
   C:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   C:        <host:name>ns1.example.com</host:name>
   C:        <host:name>ns2.example.com</host:name>
   C:        <host:name>ns3.example.com</host:name>
   C:      </host:check>
   C:    </check>
   C:    <clTRID>ABC-12345</clTRID>
   C:  </command>
   C:</epp>

   When a <check> command has been processed successfully, the EPP
   <resData> element MUST contain a child <host:chkData> element that
   identifies the host namespace.  The <host:chkData> element contains
   one or more <host:cd> elements that contain the following child
   elements:

   -  A <host:name> element that contains the fully qualified name of
      the queried host object.  This element MUST contain an "avail"
      attribute whose value indicates object availability (can it be
      provisioned or not) at the moment the <check> command was
      completed.  A value of "1" or "true" means that the object can be
      provisioned.  A value of "0" or "false" means that the object
      cannot be provisioned.

   -  An OPTIONAL <host:reason> element that MAY be provided when an
      object cannot be provisioned.  If present, this element contains
      server-specific text to help explain why the object cannot be
      provisioned.  This text MUST be represented in the response
      language previously negotiated with the client; an OPTIONAL "lang"
      attribute MAY be present to identify the language if the
      negotiated value is something other than the default value of "en"
      (English).

   Example <check> response:

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1000">
   S:      <msg>Command completed successfully</msg>
   S:    </result>
   S:    <resData>
   S:      <host:chkData
   S:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   S:        <host:cd>
   S:          <host:name avail="1">ns1.example.com</host:name>
   S:        </host:cd>
   S:        <host:cd>
   S:          <host:name avail="0">ns2.example2.com</host:name>
   S:          <host:reason>In use</host:reason>
   S:        </host:cd>
   S:        <host:cd>
   S:          <host:name avail="1">ns3.example3.com</host:name>
   S:        </host:cd>
   S:      </host:chkData>
   S:    </resData>
   S:    <trID>
   S:      <clTRID>ABC-12345</clTRID>

   S:      <svTRID>54322-XYZ</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

   An EPP error response MUST be returned if a <check> command cannot be
   processed for any reason.

3.1.2.  EPP <info> Command

   The EPP <info> command is used to retrieve information associated
   with a host object.  In addition to the standard EPP command
   elements, the <info> command MUST contain a <host:info> element that
   identifies the host namespace.  The <host:info> element contains the
   following child elements:

   -  A <host:name> element that contains the fully qualified name of
      the host object for which information is requested.


   Example <info> command:

   C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:  <command>
   C:    <info>
   C:      <host:info
   C:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   C:        <host:name>ns1.example.com</host:name>
   C:      </host:info>
   C:    </info>
   C:    <clTRID>ABC-12345</clTRID>
   C:  </command>
   C:</epp>

   When an <info> command has been processed successfully, the EPP
   <resData> element MUST contain a child <host:infData> element that
   identifies the host namespace.  The <host:infData> element contains
   the following child elements:

   -  A <host:name> element that contains the fully qualified name of
      the host object.

   -  A <host:roid> element that contains the Repository Object
      IDentifier assigned to the host object when the object was
      created.

   -  One or more <host:status> elements that describe the status of the
      host object.

   -  Zero or more <host:addr> elements that contain the IP addresses
      associated with the host object.

   -  A <host:clID> element that contains the identifier of the
      sponsoring client.

   -  A <host:crID> element that contains the identifier of the client
      that created the host object.

   -  A <host:crDate> element that contains the date and time of host
      object creation.

   -  A <host:upID> element that contains the identifier of the client
      that last updated the host object.  This element MUST NOT be
      present if the host object has never been modified.

   -  A <host:upDate> element that contains the date and time of the
      most recent host object modification.  This element MUST NOT be
      present if the host object has never been modified.

   -  A <host:trDate> element that contains the date and time of the
      most recent successful host object transfer.  This element MUST
      NOT be provided if the host object has never been transferred.
      Note that host objects MUST NOT be transferred directly; host
      objects MUST be transferred implicitly when the host object's
      superordinate domain object is transferred.  Host objects that are
      subject to transfer when transferring a domain object are listed
      in the response to an EPP <info> command performed on the domain
      object.

   Example <info> response:

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1000">
   S:      <msg>Command completed successfully</msg>
   S:    </result>
   S:    <resData>
   S:      <host:infData
   S:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   S:        <host:name>ns1.example.com</host:name>
   S:        <host:roid>NS1_EXAMPLE1-REP</host:roid>
   S:        <host:status s="linked"/>
   S:        <host:status s="clientUpdateProhibited"/>

   S:        <host:addr ip="v4">192.0.2.2</host:addr>
   S:        <host:addr ip="v4">192.0.2.29</host:addr>
   S:        <host:addr ip="v6">1080:0:0:0:8:800:200C:417A</host:addr>
   S:        <host:clID>ClientY</host:clID>
   S:        <host:crID>ClientX</host:crID>
   S:        <host:crDate>1999-04-03T22:00:00.0Z</host:crDate>
   S:        <host:upID>ClientX</host:upID>
   S:        <host:upDate>1999-12-03T09:00:00.0Z</host:upDate>
   S:        <host:trDate>2000-04-08T09:00:00.0Z</host:trDate>
   S:      </host:infData>
   S:    </resData>
   S:    <trID>
   S:      <clTRID>ABC-12345</clTRID>
   S:      <svTRID>54322-XYZ</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

   An EPP error response MUST be returned if an <info> command cannot be
   processed for any reason.

3.1.3.  EPP <transfer> Query Command

   Transfer semantics do not directly apply to host objects, so there is
   no mapping defined for the EPP <transfer> query command.

3.2.  EPP Transform Commands

   EPP provides three commands to transform host objects: <create> to
   create an instance of a host object, <delete> to delete an instance
   of a host object, and <update> to change information associated with
   a host object.  This document does not define host object mappings
   for the EPP <renew> and <transfer> commands.

   Transform commands are typically processed and completed in real
   time.  Server operators MAY receive and process transform commands,
   but defer completing the requested action if human or third-party
   review is required before the requested action can be completed.  In
   such situations, the server MUST return a 1001 response code to the
   client to note that the command has been received and processed, but
   the requested action is pending.  The server MUST also manage the
   status of the object that is the subject of the command to reflect
   the initiation and completion of the requested action.  Once the
   action has been completed, all clients involved in the transaction
   MUST be notified using a service message that the action has been
   completed and that the status of the object has changed.

3.2.1.  EPP <create> Command

   The EPP <create> command provides a transform operation that allows a
   client to create a host object.  In addition to the standard EPP
   command elements, the <create> command MUST contain a <host:create>
   element that identifies the host namespace.  The <host:create>
   element contains the following child elements:

   -  A <host:name> element that contains the fully qualified name of
      the host object to be created.

   -  Zero or more <host:addr> elements that contain the IP addresses to
      be associated with the host.  Each element MAY contain an "ip"
      attribute to identify the IP address format.  Attribute value "v4"
      is used to note IPv4 address format.  Attribute value "v6" is used
      to note IPv6 address format.  If the "ip" attribute is not
      specified, "v4" is the default attribute value.

   Hosts can be provisioned for use as name servers in the Domain Name
   System (DNS), described in [RFC1034] and [RFC1035].  Hosts

   provisioned as name servers might be subject to server operator
   policies that require or prohibit specification of IP addresses
   depending on the name of the host and the name space in which the
   server will be used as a name server.  When provisioned for use as a
   name server, IP addresses are REQUIRED only as needed to produce DNS
   glue records.  For example, if the server is authoritative for the
   "com" name space and the name of the server is "ns1.example.net", the
   server is not required to produce DNS glue records for the name
   server and IP addresses for the server are not required by the DNS.

   If the host name exists in a name space for which the server is
   authoritative, then the superordinate domain of the host MUST be
   known to the server before the host object can be created.

   Example <create> command:

   C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:  <command>
   C:    <create>
   C:      <host:create
   C:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   C:        <host:name>ns1.example.com</host:name>
   C:        <host:addr ip="v4">192.0.2.2</host:addr>
   C:        <host:addr ip="v4">192.0.2.29</host:addr>
   C:        <host:addr ip="v6">1080:0:0:0:8:800:200C:417A</host:addr>
   C:      </host:create>

   C:    </create>
   C:    <clTRID>ABC-12345</clTRID>
   C:  </command>
   C:</epp>

   When a <create> command has been processed successfully, the EPP
   <resData> element MUST contain a child <host:creData> element that
   identifies the host namespace.  The <host:creData> element contains
   the following child elements:

   -  A <host:name> element that contains the fully qualified name of
      the host object.

   -  A <host:crDate> element that contains the date and time of host
      object creation.

   Example <create> response:

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1000">
   S:      <msg>Command completed successfully</msg>
   S:    </result>
   S:    <resData>
   S:      <host:creData
   S:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   S:        <host:name>ns1.example.com</host:name>
   S:        <host:crDate>1999-04-03T22:00:00.0Z</host:crDate>
   S:      </host:creData>
   S:    </resData>
   S:    <trID>
   S:      <clTRID>ABC-12345</clTRID>
   S:      <svTRID>54322-XYZ</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

   An EPP error response MUST be returned if a <create> command cannot
   be processed for any reason.

3.2.2.  EPP <delete> Command

   The EPP <delete> command provides a transform operation that allows a
   client to delete a host object.  In addition to the standard EPP
   command elements, the <delete> command MUST contain a <host:delete>
   element that identifies the host namespace.  The <host:delete>
   element contains the following child elements:

   -  A <host:name> element that contains the fully qualified name of
      the host object to be deleted.

   A host name object SHOULD NOT be deleted if the host object is
   associated with any other object.  For example, if the host object is
   associated with a domain object, the host object SHOULD NOT be
   deleted until the existing association has been broken.  Deleting a
   host object without first breaking existing associations can cause
   DNS resolution failure for domain objects that refer to the deleted
   host object.

   Example <delete> command:

   C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:  <command>
   C:    <delete>
   C:      <host:delete
   C:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   C:        <host:name>ns1.example.com</host:name>
   C:      </host:delete>
   C:    </delete>
   C:    <clTRID>ABC-12345</clTRID>
   C:  </command>
   C:</epp>

   When a <delete> command has been processed successfully, a server
   MUST respond with an EPP response with no <resData> element.

   Example <delete> response:

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1000">
   S:      <msg>Command completed successfully</msg>
   S:    </result>
   S:    <trID>
   S:      <clTRID>ABC-12345</clTRID>
   S:      <svTRID>54321-XYZ</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

   An EPP error response MUST be returned if a <delete> command cannot
   be processed for any reason.

3.2.3.  EPP <renew> Command

   Renewal semantics do not apply to host objects, so there is no
   mapping defined for the EPP <renew> command.

3.2.4.  EPP <transfer> Command

   Transfer semantics do not directly apply to host objects, so there is
   no mapping defined for the EPP <transfer> command.  Host objects are
   subordinate to an existing superordinate domain object, and as such
   they are subject to transfer when a domain object is transferred.

3.2.5.  EPP <update> Command

   The EPP <update> command provides a transform operation that allows a
   client to modify the attributes of a host object.  In addition to the
   standard EPP command elements, the <update> command MUST contain a
   <host:update> element that identifies the host namespace.  The <host:
   update> element contains the following child elements:

   -  A <host:name> element that contains the fully qualified name of
      the host object to be updated.

   -  An OPTIONAL <host:add> element that contains attribute values to
      be added to the object.

   -  An OPTIONAL <host:rem> element that contains attribute values to
      be removed from the object.

   -  An OPTIONAL <host:chg> element that contains object attribute
      values to be changed.

   At least one <host:add>, <host:rem>, or <host:chg> element MUST be
   provided if the command is not being extended.  All of these elements
   MAY be omitted if an <update> extension is present.  The <host:add>
   and <host:rem> elements contain the following child elements:

   -  One or more <host:addr> elements that contain IP addresses to be
      associated with or removed from the host object.  IP address
      restrictions described in the <create> command mapping apply here
      as well.

   -  One or more <host:status> elements that contain status values to
      be associated with or removed from the object.  When specifying a
      value to be removed, only the attribute value is significant;
      element text is not required to match a value for removal.

   A <host:chg> element contains the following child elements:

   -  A <host:name> element that contains a new fully qualified host
      name by which the host object will be known.

   Host name changes MAY require the addition or removal of IP addresses
   to be accepted by the server.  IP address association MAY be subject
   to server policies for provisioning hosts as name servers.

   Host name changes can have an impact on associated objects that refer
   to the host object.  A host name change SHOULD NOT require additional
   updates of associated objects to preserve existing associations, with
   one exception: changing an external host object that has associations
   with objects that are sponsored by a different client.  Attempts to
   update such hosts directly MUST fail with EPP error code 2305.  The
   change can be provisioned by creating a new external host with a new
   name and needed new attributes and subsequently updating the other
   objects sponsored by the client.

   Example <update> command:

   C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:  <command>
   C:    <update>
   C:      <host:update
   C:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   C:        <host:name>ns1.example.com</host:name>
   C:        <host:add>
   C:          <host:addr ip="v4">192.0.2.22</host:addr>
   C:          <host:status s="clientUpdateProhibited"/>
   C:        </host:add>
   C:        <host:rem>
   C:          <host:addr ip="v6">1080:0:0:0:8:800:200C:417A</host:addr>
   C:        </host:rem>
   C:        <host:chg>
   C:          <host:name>ns2.example.com</host:name>
   C:        </host:chg>
   C:      </host:update>
   C:    </update>
   C:    <clTRID>ABC-12345</clTRID>
   C:  </command>
   C:</epp>

   When an <update> command has been processed successfully, a server
   MUST respond with an EPP response with no <resData> element.

   Example <update> response:

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1000">
   S:      <msg>Command completed successfully</msg>
   S:    </result>
   S:    <trID>
   S:      <clTRID>ABC-12345</clTRID>
   S:      <svTRID>54321-XYZ</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

   An EPP error response MUST be returned if an <update> command could
   not be processed for any reason.

3.3.  Offline Review of Requested Actions

   Commands are processed by a server in the order they are received
   from a client.  Though an immediate response confirming receipt and
   processing of the command is produced by the server, a server
   operator MAY perform an offline review of requested transform
   commands before completing the requested action.  In such situations,
   the response from the server MUST clearly note that the transform
   command has been received and processed, but the requested action is
   pending.  The status of the corresponding object MUST clearly reflect
   processing of the pending action.  The server MUST notify the client
   when offline processing of the action has been completed.

   Examples describing a <create> command that requires offline review
   are included here.  Note the result code and message returned in
   response to the <create> command.

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1001">
   S:      <msg>Command completed successfully; action pending</msg>
   S:    </result>
   S:    <resData>
   S:      <host:creData
   S:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   S:        <host:name>ns1.example.com</host:name>
   S:        <host:crDate>1999-04-03T22:00:00.0Z</host:crDate>
   S:      </host:creData>
   S:    </resData>

   S:    <trID>
   S:      <clTRID>ABC-12345</clTRID>
   S:      <svTRID>54322-XYZ</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

   The status of the host object after returning this response MUST
   include "pendingCreate".  The server operator reviews the request
   offline, and informs the client of the outcome of the review either
   by queuing a service message for retrieval via the <poll> command or
   by using an out-of-band mechanism to inform the client of the
   request.

   The service message MUST contain text in the <response>, <msgQ>,
   <msg> element that describes the notification.  In addition, the EPP
   <resData> element MUST contain a child <host:panData> element that
   identifies the host namespace.  The <host:panData> element contains
   the following child elements:

   -  A <host:name> element that contains the fully qualified name of
      the host object.  The <host:name> element contains a REQUIRED
      "paResult" attribute.  A positive boolean value indicates that the
      request has been approved and completed.  A negative boolean value
      indicates that the request has been denied and the requested
      action has not been taken.

   -  A <host:paTRID> element that contains the client transaction
      identifier and server transaction identifier returned with the
      original response to process the command.  The client transaction
      identifier is OPTIONAL and will only be returned if the client
      provided an identifier with the original <create> command.

   -  A <host:paDate> element that contains the date and time describing
      when review of the requested action was completed.

   Example "review completed" service message:

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1301">
   S:      <msg>Command completed successfully; ack to dequeue</msg>
   S:    </result>
   S:    <msgQ count="5" id="12345">
   S:      <qDate>1999-04-04T22:01:00.0Z</qDate>
   S:      <msg>Pending action completed successfully.</msg>
   S:    </msgQ>

   S:    <resData>
   S:      <host:panData
   S:       xmlns:host="urn:ietf:params:xml:ns:host-1.0">
   S:        <host:name paResult="1">ns1.example.com</host:name>
   S:        <host:paTRID>
   S:          <clTRID>ABC-12345</clTRID>
   S:          <svTRID>54322-XYZ</svTRID>
   S:        </host:paTRID>
   S:        <host:paDate>1999-04-04T22:00:00.0Z</host:paDate>
   S:      </host:panData>
   S:    </resData>
   S:    <trID>
   S:      <clTRID>BCD-23456</clTRID>
   S:      <svTRID>65432-WXY</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

4.  Formal Syntax

   An EPP object mapping is specified in XML Schema notation.  The
   formal syntax presented here is a complete schema representation of
   the object mapping suitable for automated validation of EPP XML
   instances.  The BEGIN and END tags are not part of the schema; they
   are used to note the beginning and ending of the schema for URI
   registration purposes.

   BEGIN
   <?xml version="1.0" encoding="UTF-8"?>

   <schema targetNamespace="urn:ietf:params:xml:ns:host-1.0"
          xmlns:host="urn:ietf:params:xml:ns:host-1.0"
          xmlns:epp="urn:ietf:params:xml:ns:epp-1.0"
          xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0"
          xmlns="http://www.w3.org/2001/XMLSchema"
          elementFormDefault="qualified">

   <!--
   Import common element types.
   -->
    <import namespace="urn:ietf:params:xml:ns:eppcom-1.0"/>
    <import namespace="urn:ietf:params:xml:ns:epp-1.0"/>

    <annotation>
      <documentation>
        Extensible Provisioning Protocol v1.0
        host provisioning schema.
      </documentation>

    </annotation>

   <!--
   Child elements found in EPP commands.
   -->
    <element name="check" type="host:mNameType"/>
    <element name="create" type="host:createType"/>
    <element name="delete" type="host:sNameType"/>
    <element name="info" type="host:sNameType"/>
    <element name="update" type="host:updateType"/>

   <!--
   Child elements of the <create> command.
   -->
    <complexType name="createType">
      <sequence>
        <element name="name" type="eppcom:labelType"/>
        <element name="addr" type="host:addrType"
         minOccurs="0" maxOccurs="unbounded"/>
      </sequence>
    </complexType>

    <complexType name="addrType">
      <simpleContent>
        <extension base="host:addrStringType">
          <attribute name="ip" type="host:ipType"
           default="v4"/>
        </extension>
      </simpleContent>
    </complexType>

    <simpleType name="addrStringType">
      <restriction base="token">
        <minLength value="3"/>
        <maxLength value="45"/>
      </restriction>
    </simpleType>

    <simpleType name="ipType">
      <restriction base="token">
        <enumeration value="v4"/>
        <enumeration value="v6"/>
      </restriction>
    </simpleType>

   <!--
   Child elements of the <delete> and <info> commands.
   -->

    <complexType name="sNameType">
      <sequence>
        <element name="name" type="eppcom:labelType"/>
      </sequence>
    </complexType>

   <!--
   Child element of commands that accept multiple names.
   -->
    <complexType name="mNameType">
      <sequence>
        <element name="name" type="eppcom:labelType"
         maxOccurs="unbounded"/>
      </sequence>
    </complexType>
   <!--
   Child elements of the <update> command.
   -->
    <complexType name="updateType">
      <sequence>
        <element name="name" type="eppcom:labelType"/>
        <element name="add" type="host:addRemType"
         minOccurs="0"/>
        <element name="rem" type="host:addRemType"
         minOccurs="0"/>
        <element name="chg" type="host:chgType"
         minOccurs="0"/>
      </sequence>
    </complexType>

   <!--
   Data elements that can be added or removed.
   -->
    <complexType name="addRemType">
      <sequence>
        <element name="addr" type="host:addrType"
         minOccurs="0" maxOccurs="unbounded"/>
        <element name="status" type="host:statusType"
         minOccurs="0" maxOccurs="7"/>
      </sequence>
    </complexType>

   <!--
   Data elements that can be changed.
   -->
    <complexType name="chgType">
      <sequence>
        <element name="name" type="eppcom:labelType"/>

      </sequence>
    </complexType>

   <!--
   Child response elements.
   -->
    <element name="chkData" type="host:chkDataType"/>
    <element name="creData" type="host:creDataType"/>
    <element name="infData" type="host:infDataType"/>
    <element name="panData" type="host:panDataType"/>

   <!--
   <check> response elements.
   -->
    <complexType name="chkDataType">
      <sequence>
        <element name="cd" type="host:checkType"
         maxOccurs="unbounded"/>
      </sequence>
    </complexType>

    <complexType name="checkType">
      <sequence>
        <element name="name" type="host:checkNameType"/>
        <element name="reason" type="eppcom:reasonType"
         minOccurs="0"/>
      </sequence>
    </complexType>

    <complexType name="checkNameType">
      <simpleContent>
        <extension base="eppcom:labelType">
          <attribute name="avail" type="boolean"
           use="required"/>
        </extension>
      </simpleContent>
    </complexType>

   <!--
   <create> response elements.
   -->
    <complexType name="creDataType">
      <sequence>
        <element name="name" type="eppcom:labelType"/>
        <element name="crDate" type="dateTime"/>
      </sequence>
    </complexType>

   <!--
   <info> response elements.
   -->
    <complexType name="infDataType">
      <sequence>
        <element name="name" type="eppcom:labelType"/>
        <element name="roid" type="eppcom:roidType"/>
        <element name="status" type="host:statusType"
         maxOccurs="7"/>
        <element name="addr" type="host:addrType"
         minOccurs="0" maxOccurs="unbounded"/>
        <element name="clID" type="eppcom:clIDType"/>
        <element name="crID" type="eppcom:clIDType"/>
        <element name="crDate" type="dateTime"/>
        <element name="upID" type="eppcom:clIDType"
         minOccurs="0"/>
        <element name="upDate" type="dateTime"
         minOccurs="0"/>
        <element name="trDate" type="dateTime"
         minOccurs="0"/>
      </sequence>
    </complexType>

   <!--
   Status is a combination of attributes and an optional human-readable
   message that may be expressed in languages other than English.
   -->
    <complexType name="statusType">
      <simpleContent>
        <extension base="normalizedString">
          <attribute name="s" type="host:statusValueType"
           use="required"/>
          <attribute name="lang" type="language"
           default="en"/>
        </extension>
      </simpleContent>
    </complexType>

    <simpleType name="statusValueType">
      <restriction base="token">
        <enumeration value="clientDeleteProhibited"/>
        <enumeration value="clientUpdateProhibited"/>
        <enumeration value="linked"/>
        <enumeration value="ok"/>
        <enumeration value="pendingCreate"/>
        <enumeration value="pendingDelete"/>
        <enumeration value="pendingTransfer"/>
        <enumeration value="pendingUpdate"/>

        <enumeration value="serverDeleteProhibited"/>
        <enumeration value="serverUpdateProhibited"/>
      </restriction>
    </simpleType>

   <!--
   Pending action notification response elements.
   -->
    <complexType name="panDataType">
      <sequence>
        <element name="name" type="host:paNameType"/>
        <element name="paTRID" type="epp:trIDType"/>
        <element name="paDate" type="dateTime"/>
      </sequence>
    </complexType>
    <complexType name="paNameType">
      <simpleContent>
        <extension base="eppcom:labelType">
          <attribute name="paResult" type="boolean"
           use="required"/>
        </extension>
      </simpleContent>
    </complexType>

   <!--
   End of schema.
   -->
   </schema>
   END

5.  Internationalization Considerations

   EPP is represented in XML, which provides native support for encoding
   information using the Unicode character set and its more compact
   representations including UTF-8.  Conformant XML processors recognize
   both UTF-8 and UTF-16 [RFC2781].  Though XML includes provisions to
   identify and use other character encodings through use of an
   "encoding" attribute in an <?xml?> declaration, use of UTF-8 is
   RECOMMENDED in environments where parser encoding support
   incompatibility exists.

   All date-time values presented via EPP MUST be expressed in Universal
   Coordinated Time using the Gregorian calendar.  XML Schema allows use
   of time zone identifiers to indicate offsets from the zero meridian,
   but this option MUST NOT be used with EPP.  The extended date-time
   form using upper case "T" and "Z" characters defined in

   [W3C.REC-xmlschema-2-20041028] MUST be used to represent date-time
   values as XML Schema does not support truncated date-time forms or
   lower case "T" and "Z" characters.

   This document requires host name syntax as specified in [RFC0952] as
   updated by [RFC1123].  At the time of this writing, RFC 3490
   [RFC3490] describes a standard to use certain ASCII name labels to
   represent non-ASCII name labels.  These conformance requirements
   might change as a result of progressing work in developing standards
   for internationalized host names.

6.  IANA Considerations

   This document uses URNs to describe XML namespaces and XML schemas
   conforming to a registry mechanism described in [RFC3688].  Two URI
   assignments have been registered by the IANA.

   Registration request for the host namespace:

   URI: urn:ietf:params:xml:ns:host-1.0

   Registrant Contact: See the "Author's Address" section of this
   document.

   XML: None.  Namespace URIs do not represent an XML specification.

   Registration request for the host XML schema:

   URI: urn:ietf:params:xml:schema:host-1.0

   Registrant Contact: See the "Author's Address" section of this
   document.

   XML: See the "Formal Syntax" section of this document.

7.  Security Considerations

   The object mapping described in this document does not provide any
   security services or introduce any additional considerations beyond
   those described by [RFC4930] and protocol layers used by EPP.

8.  Acknowledgements

   This document was originally written as an individual submission
   Internet-Draft.  The PROVREG working group later adopted it as a
   working group document and provided many invaluable comments and
   suggested improvements.  The author wishes to acknowledge the efforts
   of WG chairs Edward Lewis and Jaap Akkerhuis for their process and
   editorial contributions.

   Specific suggestions that have been incorporated into this document
   were provided by Chris Bason, Jordyn Buchanan, Dave Crocker, Anthony
   Eden, Sheer El-Showk, Klaus Malorny, Dan Manley, Michael Mealling,
   Patrick Mevzek, and Rick Wesson.

9.  References

9.1.  Normative References

   [RFC0791]  Postel, J., "Internet Protocol", STD 5, RFC 791,
              September 1981.

   [RFC0952]  Harrenstien, K., Stahl, M., and E. Feinler, "DoD Internet
              host table specification", RFC 952, October 1985.

   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
              STD 13, RFC 1034, November 1987.

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, November 1987.

   [RFC1123]  Braden, R., "Requirements for Internet Hosts - Application
              and Support", STD 3, RFC 1123, October 1989.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              January 2004.

   [RFC4291]  Hinden, R. and S. Deering, "IP Version 6 Addressing
              Architecture", RFC 4291, February 2006.

   [RFC4930]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
              RFC 4930, May 2007.

   [W3C.REC-xml-20040204]
              Yergeau, F., Maler, E., Sperberg-McQueen, C., Bray, T.,
              and J. Paoli, "Extensible Markup Language (XML) 1.0 (Third
              Edition)", World Wide Web Consortium FirstEdition REC-xml-
              20040204, February 2004,
              <http://www.w3.org/TR/2004/REC-xml-20040204>.

   [W3C.REC-xmlschema-1-20041028]
              Thompson, H., Maloney, M., Mendelsohn, N., and D. Beech,
              "XML Schema Part 1: Structures Second Edition", World Wide
              Web Consortium Recommendation REC-xmlschema-1-20041028,
              October 2004,
              <http://www.w3.org/TR/2004/REC-xmlschema-1-20041028>.

   [W3C.REC-xmlschema-2-20041028]
              Biron, P. and A. Malhotra, "XML Schema Part 2: Datatypes
              Second Edition", World Wide Web Consortium
              Recommendation REC-xmlschema-2-20041028, October 2004,
              <http://www.w3.org/TR/2004/REC-xmlschema-2-20041028>.

9.2.  Informative References

   [RFC1886]  Thomson, S. and C. Huitema, "DNS Extensions to support IP
              version 6", RFC 1886, December 1995.

   [RFC2781]  Hoffman, P. and F. Yergeau, "UTF-16, an encoding of ISO
              10646", RFC 2781, February 2000.

   [RFC2874]  Crawford, M. and C. Huitema, "DNS Extensions to Support
              IPv6 Address Aggregation and Renumbering", RFC 2874,
              July 2000.

   [RFC3152]  Bush, R., "Delegation of IP6.ARPA", BCP 49, RFC 3152,
              August 2001.

   [RFC3490]  Faltstrom, P., Hoffman, P., and A. Costello,
              "Internationalizing Domain Names in Applications (IDNA)",
              RFC 3490, March 2003.

   [RFC3732]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
              Host Mapping", RFC 3732, March 2004.

Appendix A.  Changes from RFC 3732

   1.  Minor reformatting as a result of converting I-D source format
       from nroff to XML.

   2.  Removed this text from Section 2.3:

       "Transform commands MUST be rejected when a pendingCreate,
       pendingDelete, pendingTransfer, or pendingUpdate status is set."

   3.  Changed text in Section 3.2.2 from this:

       "A host name object MUST NOT be deleted if the host object is
       associated with any other object.  For example, if the host
       object is associated with a domain object, the host object MUST
       NOT be deleted until the existing association has been broken."

       to this:

       "A host name object SHOULD NOT be deleted if the host object is
       associated with any other object.  For example, if the host
       object is associated with a domain object, the host object SHOULD
       NOT be deleted until the existing association has been broken.
       Deleting a host object without first breaking existing
       associations can cause DNS resolution failure for domain objects
       that refer to the deleted host object."

   4.  Changed text in Section 3.2.5 from "At least one <host:add>,
       <host:rem>, or <host:chg> element MUST be provided." to "At least
       one <host:add>, <host:rem>, or <host:chg> element MUST be
       provided if the command is not being extended.  All of these
       elements MAY be omitted if an <update> extension is present."

   5.  Changed text in Section 3.3 (old Section 3.2.6) from this:

       "The server operator reviews the request offline, and informs the
       client of the outcome of the review by queuing a service message
       for retrieval via the <poll> command."

       to this:

       "The server operator reviews the request offline, and informs the
       client of the outcome of the review either by queuing a service
       message for retrieval via the <poll> command or by using an out-
       of-band mechanism to inform the client of the request."

   6.  Removed text describing use of the XML Schema schemaLocation
       attribute.  This is an optional attribute that doesn't need to be
       mandated for use in EPP.

   7.  Removed references to RFC 3339 and replaced them with references
       to the W3C XML Schema specification.

   8.  Replaced references to RFC 3513 with references to RFC 4291.

   9.  Updated EPP and XML references.

Author's Address

   Scott Hollenbeck
   VeriSign, Inc.
   21345 Ridgetop Circle
   Dulles, VA  20166-6503
   US

   EMail: shollenbeck@verisign.com

Full Copyright Statement

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Acknowledgement

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