Network Working Group J. Schoenwaelder, Ed.
Internet-Draft Jacobs University
Obsoletes: 6021 (if approved) April 11, 2013
Intended status: Standards Track
Expires: October 13, 2013

Common YANG Data Types
draft-ietf-netmod-rfc6021-bis-01

Abstract

This document introduces a collection of common data types to be used with the YANG data modeling language. This document obsoletes RFC 6021.

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 http://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 October 13, 2013.

Copyright Notice

Copyright (c) 2013 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.


Table of Contents

1. Introduction

YANG [RFC6020] is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF) [RFC6241]. The YANG language supports a small set of built-in data types and provides mechanisms to derive other types from the built-in types.

This document introduces a collection of common data types derived from the built-in YANG data types. The derived types are designed to be applicable for modeling all areas of management information. The definitions are organized in several YANG modules. The "ietf‑yang‑types" module contains generally useful data types. The "ietf‑inet‑types" module contains definitions that are relevant for the Internet protocol suite.

This version of the document adds new type definitions to the YANG modules and obsoletes [RFC6021]. For the further details, see the revision statement of the YANG modules.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119].

2. Overview

This section provides a short overview of the types defined in subsequent sections and their equivalent Structure of Management Information Version 2 (SMIv2) [RFC2578][RFC2579] data types. A YANG data type is equivalent to an SMIv2 data type if the data types have the same set of values and the semantics of the values are equivalent.

Table 1 lists the types defined in the ietf-yang-types YANG module and the corresponding SMIv2 types (- indicates there is no corresponding SMIv2 type).

ietf-yang-types
YANG type Equivalent SMIv2 type (module)
counter32 Counter32 (SNMPv2-SMI)
zero-based-counter32 ZeroBasedCounter32 (RMON2-MIB)
counter64 Counter64 (SNMPv2-SMI)
zero-based-counter64 ZeroBasedCounter64 (HCNUM-TC)
gauge32 Gauge32 (SNMPv2-SMI)
gauge64 CounterBasedGauge64 (HCNUM-TC)
object-identifier -
object-identifier-128 OBJECT IDENTIFIER
yang-identifier -
date-and-time -
timeticks TimeTicks (SNMPv2-SMI)
timestamp TimeStamp (SNMPv2-TC)
phys-address PhysAddress (SNMPv2-TC)
mac-address MacAddress (SNMPv2-TC)
xpath1.0 -
hex-string -
uuid -
dotted-quad -

Table 2 lists the types defined in the ietf-inet-types YANG module and the corresponding SMIv2 types (if any).

ietf-inet-types
YANG type Equivalent SMIv2 type (module)
ip-version InetVersion (INET-ADDRESS-MIB)
dscp Dscp (DIFFSERV-DSCP-TC)
ipv6-flow-label IPv6FlowLabel (IPV6-FLOW-LABEL-MIB)
port-number InetPortNumber (INET-ADDRESS-MIB)
as-number InetAutonomousSystemNumber (INET-ADDRESS-MIB)
ip-address -
ipv4-address -
ipv6-address -
ip-address-no-zone -
ipv4-address-no-zone -
ipv6-address-no-zone -
ip-prefix -
ipv4-prefix -
ipv6-prefix -
domain-name -
host -
uri Uri (URI-TC-MIB)

3. Core YANG Derived Types

The ietf-yang-types YANG module references [IEEE802], [ISO9834-1], [RFC2578], [RFC2579], [RFC2856], [RFC3339], [RFC4122], [RFC4502], [RFC6020], [XPATH], and [XSD-TYPES].

<CODE BEGINS> file "ietf-yang-types@2013-03-25.yang"

module ietf-yang-types {
  
  namespace "urn:ietf:params:xml:ns:yang:ietf-yang-types";
  prefix "yang";

  organization
   "IETF NETMOD (NETCONF Data Modeling Language) Working Group";

  contact
   "WG Web:   <http://tools.ietf.org/wg/netmod/>
    WG List:  <mailto:netmod@ietf.org>

    WG Chair: David Kessens
              <mailto:david.kessens@nsn.com>

    WG Chair: Juergen Schoenwaelder
              <mailto:j.schoenwaelder@jacobs-university.de>

    Editor:   Juergen Schoenwaelder
              <mailto:j.schoenwaelder@jacobs-university.de>";

  description
   "This module contains a collection of generally useful derived
    YANG data types.

    Copyright (c) 2013 IETF Trust and the persons identified as
    authors of the code.  All rights reserved.

    Redistribution and use in source and binary forms, with or
    without modification, is permitted pursuant to, and subject
    to the license terms contained in, the Simplified BSD License
    set forth in Section 4.c of the IETF Trust's Legal Provisions
    Relating to IETF Documents
    (http://trustee.ietf.org/license-info).

    This version of this YANG module is part of RFC XXXX; see
    the RFC itself for full legal notices.";

  revision 2013-03-25 {
    description
     "This revision adds the following new data types:
      - yang-identifier
      - hex-string
      - uuid
      - dotted-quad";
    reference 
     "RFC XXXX: Common YANG Data Types";
  }

  revision 2010-09-24 {
    description
     "Initial revision.";
    reference 
     "RFC 6021: Common YANG Data Types";
  }

  /*** collection of counter and gauge types ***/

  typedef counter32 {
    type uint32;
    description
     "The counter32 type represents a non-negative integer
      that monotonically increases until it reaches a
      maximum value of 2^32-1 (4294967295 decimal), when it
      wraps around and starts increasing again from zero.

      Counters have no defined 'initial' value, and thus, a
      single value of a counter has (in general) no information
      content.  Discontinuities in the monotonically increasing
      value normally occur at re-initialization of the
      management system, and at other times as specified in the
      description of a schema node using this type.  If such 
      other times can occur, for example, the creation of
      a schema node of type counter32 at times other than
      re-initialization, then a corresponding schema node 
      should be defined, with an appropriate type, to indicate
      the last discontinuity.

      The counter32 type should not be used for configuration
      schema nodes.  A default statement SHOULD NOT be used in
      combination with the type counter32.

      In the value set and its semantics, this type is equivalent
      to the Counter32 type of the SMIv2.";
    reference
     "RFC 2578: Structure of Management Information Version 2
                (SMIv2)";
  }

  typedef zero-based-counter32 {
    type yang:counter32;
    default "0";
    description
     "The zero-based-counter32 type represents a counter32
      that has the defined 'initial' value zero.

      A schema node of this type will be set to zero (0) on creation
      and will thereafter increase monotonically until it reaches
      a maximum value of 2^32-1 (4294967295 decimal), when it
      wraps around and starts increasing again from zero.

      Provided that an application discovers a new schema node
      of this type within the minimum time to wrap, it can use the
      'initial' value as a delta.  It is important for a management 
      station to be aware of this minimum time and the actual time
      between polls, and to discard data if the actual time is too
      long or there is no defined minimum time.

      In the value set and its semantics, this type is equivalent
      to the ZeroBasedCounter32 textual convention of the SMIv2.";
    reference
      "RFC 4502: Remote Network Monitoring Management Information
                 Base Version 2";
  }

  typedef counter64 {
    type uint64;
    description
     "The counter64 type represents a non-negative integer
      that monotonically increases until it reaches a
      maximum value of 2^64-1 (18446744073709551615 decimal),
      when it wraps around and starts increasing again from zero.

      Counters have no defined 'initial' value, and thus, a
      single value of a counter has (in general) no information
      content.  Discontinuities in the monotonically increasing
      value normally occur at re-initialization of the
      management system, and at other times as specified in the
      description of a schema node using this type.  If such
      other times can occur, for example, the creation of
      a schema node of type counter64 at times other than
      re-initialization, then a corresponding schema node
      should be defined, with an appropriate type, to indicate
      the last discontinuity.

      The counter64 type should not be used for configuration
      schema nodes.  A default statement SHOULD NOT be used in
      combination with the type counter64.

      In the value set and its semantics, this type is equivalent
      to the Counter64 type of the SMIv2.";
    reference
     "RFC 2578: Structure of Management Information Version 2
                (SMIv2)";
  }

  typedef zero-based-counter64 {
    type yang:counter64;
    default "0";
    description
     "The zero-based-counter64 type represents a counter64 that
      has the defined 'initial' value zero.

      A schema node of this type will be set to zero (0) on creation
      and will thereafter increase monotonically until it reaches
      a maximum value of 2^64-1 (18446744073709551615 decimal), 
      when it wraps around and starts increasing again from zero.

      Provided that an application discovers a new schema node
      of this type within the minimum time to wrap, it can use the
      'initial' value as a delta.  It is important for a management
      station to be aware of this minimum time and the actual time
      between polls, and to discard data if the actual time is too
      long or there is no defined minimum time.

      In the value set and its semantics, this type is equivalent
      to the ZeroBasedCounter64 textual convention of the SMIv2.";
    reference
     "RFC 2856: Textual Conventions for Additional High Capacity 
                Data Types";
  }

  typedef gauge32 {
    type uint32;
    description
     "The gauge32 type represents a non-negative integer, which 
      may increase or decrease, but shall never exceed a maximum
      value, nor fall below a minimum value.  The maximum value
      cannot be greater than 2^32-1 (4294967295 decimal), and
      the minimum value cannot be smaller than 0.  The value of
      a gauge32 has its maximum value whenever the information
      being modeled is greater than or equal to its maximum 
      value, and has its minimum value whenever the information
      being modeled is smaller than or equal to its minimum value.
      If the information being modeled subsequently decreases
      below (increases above) the maximum (minimum) value, the
      gauge32 also decreases (increases).

      In the value set and its semantics, this type is equivalent
      to the Gauge32 type of the SMIv2.";
    reference
     "RFC 2578: Structure of Management Information Version 2
                (SMIv2)";
  }

  typedef gauge64 {
    type uint64;
    description
     "The gauge64 type represents a non-negative integer, which 
      may increase or decrease, but shall never exceed a maximum
      value, nor fall below a minimum value.  The maximum value
      cannot be greater than 2^64-1 (18446744073709551615), and 
      the minimum value cannot be smaller than 0.  The value of
      a gauge64 has its maximum value whenever the information
      being modeled is greater than or equal to its maximum
      value, and has its minimum value whenever the information
      being modeled is smaller than or equal to its minimum value.
      If the information being modeled subsequently decreases
      below (increases above) the maximum (minimum) value, the
      gauge64 also decreases (increases).

      In the value set and its semantics, this type is equivalent
      to the CounterBasedGauge64 SMIv2 textual convention defined 
      in RFC 2856";
    reference
     "RFC 2856: Textual Conventions for Additional High Capacity 
                Data Types";
  }

  /*** collection of identifier related types ***/

  typedef object-identifier {
    type string {
      pattern '(([0-1](\.[1-3]?[0-9]))|(2\.(0|([1-9]\d*))))'
            + '(\.(0|([1-9]\d*)))*';
    }
    description
     "The object-identifier type represents administratively
      assigned names in a registration-hierarchical-name tree.

      Values of this type are denoted as a sequence of numerical
      non-negative sub-identifier values.  Each sub-identifier
      value MUST NOT exceed 2^32-1 (4294967295).  Sub-identifiers
      are separated by single dots and without any intermediate
      whitespace.

      The ASN.1 standard restricts the value space of the first
      sub-identifier to 0, 1, or 2.  Furthermore, the value space
      of the second sub-identifier is restricted to the range 
      0 to 39 if the first sub-identifier is 0 or 1.  Finally, 
      the ASN.1 standard requires that an object identifier 
      has always at least two sub-identifier.  The pattern
      captures these restrictions.

      Although the number of sub-identifiers is not limited,
      module designers should realize that there may be
      implementations that stick with the SMIv2 limit of 128
      sub-identifiers.

      This type is a superset of the SMIv2 OBJECT IDENTIFIER type
      since it is not restricted to 128 sub-identifiers.  Hence,
      this type SHOULD NOT be used to represent the SMIv2 OBJECT
      IDENTIFIER type, the object-identifier-128 type SHOULD be
      used instead.";
    reference
     "ISO9834-1: Information technology -- Open Systems
      Interconnection -- Procedures for the operation of OSI
      Registration Authorities: General procedures and top
      arcs of the ASN.1 Object Identifier tree";
  }

  typedef object-identifier-128 {
    type object-identifier {
      pattern '\d*(\.\d*){1,127}';
    }
    description
     "This type represents object-identifiers restricted to 128
      sub-identifiers.

      In the value set and its semantics, this type is equivalent
      to the OBJECT IDENTIFIER type of the SMIv2.";
    reference
     "RFC 2578: Structure of Management Information Version 2
                (SMIv2)";
  }

  typedef yang-identifier {
    type string {
      length "1..max";
      pattern '[a-zA-Z_][a-zA-Z0-9\-_.]*';
      pattern '.|..|[^xX].*|.[^mM].*|..[^lL].*';
    }
    description
      "A YANG identifier string as defined in RFC 6020, page 163.
       An identifier must start with an alphabetic character or 
       an underscore followed by an arbitrary sequence of 
       alphabetic or numeric characters, underscores, hyphens
       or dots.

       A YANG identifier MUST NOT start with any possible 
       combination of the lower-case or upper-case character 
       sequence 'xml'.";
    reference
      "RFC 6020: YANG - A Data Modeling Language for the Network
                 Configuration Protocol (NETCONF)";
  }

  /*** collection of date and time related types ***/

  typedef date-and-time {
    type string {
      pattern '\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(\.\d+)?'
            + '(Z|[\+\-]\d{2}:\d{2})';
    }
    description
     "The date-and-time type is a profile of the ISO 8601
      standard for representation of dates and times using the
      Gregorian calendar.  The profile is defined by the
      date-time production in Section 5.6 of RFC 3339.

      The date-and-time type is compatible with the dateTime XML
      schema type with the following notable exceptions:

      (a) The date-and-time type does not allow negative years.

      (b) The date-and-time time-offset -00:00 indicates an unknown
          time zone (see RFC 3339) while -00:00 and +00:00 and Z all
          represent the same time zone in dateTime.

      (c) The canonical format (see below) of data-and-time values
          differs from the canonical format used by the dateTime XML
          schema type, which requires all times to be in UTC using 
          the time-offset 'Z'.

      This type is not equivalent to the DateAndTime textual 
      convention of the SMIv2 since RFC 3339 uses a different
      separator between full-date and full-time and provides
      higher resolution of time-secfrac.

      The canonical format for date-and-time values with a known time
      zone uses a numeric time zone offset that is calculated using
      the device's configured known offset to UTC time.  A change of
      the device's offset to UTC time will cause date-and-time values
      to change accordingly.  Such changes might happen periodically
      in case a server follows automatically daylight saving time
      (DST) time zone offset changes.  The canonical format for
      date-and-time values with an unknown time zone (usually 
      referring to the notion of local time) uses the time-offset
      -00:00.";
    reference
     "RFC 3339: Date and Time on the Internet: Timestamps
      RFC 2579: Textual Conventions for SMIv2
      XSD-TYPES: XML Schema Part 2: Datatypes Second Edition";
  }
    
  typedef timeticks {
    type uint32;
    description
     "The timeticks type represents a non-negative integer that
      represents the time, modulo 2^32 (4294967296 decimal), in
      hundredths of a second between two epochs.  When a schema
      node is defined that uses this type, the description of
      the schema node identifies both of the reference epochs.

      In the value set and its semantics, this type is equivalent
      to the TimeTicks type of the SMIv2.";
    reference
     "RFC 2578: Structure of Management Information Version 2
                (SMIv2)";
  }

  typedef timestamp {
    type yang:timeticks;
    description
     "The timestamp type represents the value of an associated
      timeticks schema node at which a specific occurrence 
      happened. The specific occurrence must be defined in the
      description of any schema node defined using this type.  When
      the specific occurrence occurred prior to the last time the
      associated timeticks attribute was zero, then the timestamp
      value is zero.  Note that this requires all timestamp values
      to be reset to zero when the value of the associated timeticks
      attribute reaches 497+ days and wraps around to zero.

      The associated timeticks schema node must be specified
      in the description of any schema node using this type.

      In the value set and its semantics, this type is equivalent
      to the TimeStamp textual convention of the SMIv2.";
    reference
     "RFC 2579: Textual Conventions for SMIv2";
  }

  /*** collection of generic address types ***/

  typedef phys-address {
    type string {
      pattern '([0-9a-fA-F]{2}(:[0-9a-fA-F]{2})*)?';
    }
    description
     "Represents media- or physical-level addresses represented
      as a sequence octets, each octet represented by two hexadecimal
      numbers.  Octets are separated by colons.  The canonical
      representation uses lowercase characters.

      In the value set and its semantics, this type is equivalent
      to the PhysAddress textual convention of the SMIv2.";
    reference 
     "RFC 2579: Textual Conventions for SMIv2";
  }

  typedef mac-address {
    type string {
      pattern '[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){5}';
    }
    description
     "The mac-address type represents an IEEE 802 MAC address.
      The canonical representation uses lowercase characters.

      In the value set and its semantics, this type is equivalent
      to the MacAddress textual convention of the SMIv2.";
    reference
     "IEEE 802: IEEE Standard for Local and Metropolitan Area
                Networks: Overview and Architecture
      RFC 2579: Textual Conventions for SMIv2";
  }

  /*** collection of XML specific types ***/

  typedef xpath1.0 {
    type string;
    description
     "This type represents an XPATH 1.0 expression.

      When a schema node is defined that uses this type, the
      description of the schema node MUST specify the XPath
      context in which the XPath expression is evaluated.";
    reference
     "XPATH: XML Path Language (XPath) Version 1.0";
  }

  /*** collection of string types ***/

  typedef hex-string {
    type string {
      pattern '[0-9a-fA-F]{2}(:[0-9a-fA-F]{2})*';
    }
    description
     "A hexadecimal string with octets represented as hex digits
      separated by colons.  The canonical representation uses 
      lowercase characters.";
  }

  typedef uuid {
    type string {
      pattern '[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-'
            + '[0-9a-fA-F]{4}-[0-9a-fA-F]{12}';
    }
    description
     "A Universally Unique IDentifier in the string representation
      defined in RFC 4122.  The canonical representation uses
      lowercase characters.

      The following is an example of a UUID in string representation:
      f81d4fae-7dec-11d0-a765-00a0c91e6bf6
      ";
    reference
     "RFC 4122: A Universally Unique IDentifier (UUID) URN
                Namespace";
  }

  typedef dotted-quad {
    type string {
      pattern 
        '(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}'
      + '([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])';
    }
    description
      "An unsigned 32-bit number expressed in the dotted-quad
       notation, i.e., four octets written as decimal numbers
       and separated with the '.' (full stop) character.";
  }
}
	    

<CODE ENDS>

4. Internet-Specific Derived Types

The ietf-inet-types YANG module references [RFC0768], [RFC0791], [RFC0793], [RFC0952], [RFC1034], [RFC1123], [RFC1930], [RFC2460], [RFC2474], [RFC2780], [RFC2782], [RFC3289], [RFC3305], [RFC3492], [RFC3595], [RFC3986], [RFC4001], [RFC4007], [RFC4271], [RFC4291], [RFC4340], [RFC4960], [RFC5017], [RFC5891], [RFC5952], and [RFC6793].

<CODE BEGINS> file "ietf-inet-types@2013-03-25.yang"

module ietf-inet-types {

  namespace "urn:ietf:params:xml:ns:yang:ietf-inet-types";
  prefix "inet";
  
  organization
   "IETF NETMOD (NETCONF Data Modeling Language) Working Group";
  
  contact
   "WG Web:   <http://tools.ietf.org/wg/netmod/>
    WG List:  <mailto:netmod@ietf.org>

    WG Chair: David Kessens
              <mailto:david.kessens@nsn.com>

    WG Chair: Juergen Schoenwaelder
              <mailto:j.schoenwaelder@jacobs-university.de>

    Editor:   Juergen Schoenwaelder
              <mailto:j.schoenwaelder@jacobs-university.de>";

  description
   "This module contains a collection of generally useful derived
    YANG data types for Internet addresses and related things.

    Copyright (c) 2013 IETF Trust and the persons identified as
    authors of the code.  All rights reserved.

    Redistribution and use in source and binary forms, with or
    without modification, is permitted pursuant to, and subject
    to the license terms contained in, the Simplified BSD License
    set forth in Section 4.c of the IETF Trust's Legal Provisions
    Relating to IETF Documents
    (http://trustee.ietf.org/license-info).

    This version of this YANG module is part of RFC XXXX; see 
    the RFC itself for full legal notices.";

  revision 2013-03-25 {
    description
     "This revision adds the following new data types:
      - ip-address-no-zone
      - ipv4-address-no-zone
      - ipv6-address-no-zone";
    reference 
     "RFC XXXX: Common YANG Data Types";
  }

  revision 2010-09-24 {
    description
     "Initial revision.";
    reference 
     "RFC 6021: Common YANG Data Types";
  }

  /*** collection of protocol field related types ***/

  typedef ip-version {
    type enumeration {
      enum unknown {
        value "0"; 
        description
         "An unknown or unspecified version of the Internet
          protocol.";
      }
      enum ipv4 {
        value "1";
        description
         "The IPv4 protocol as defined in RFC 791.";
      }
      enum ipv6 {
        value "2";
        description
         "The IPv6 protocol as defined in RFC 2460.";
      }
    }
    description
     "This value represents the version of the IP protocol.

      In the value set and its semantics, this type is equivalent
      to the InetVersion textual convention of the SMIv2.";
    reference
     "RFC  791: Internet Protocol
      RFC 2460: Internet Protocol, Version 6 (IPv6) Specification
      RFC 4001: Textual Conventions for Internet Network Addresses";
  }

  typedef dscp {
    type uint8 {
      range "0..63";
    }
    description
     "The dscp type represents a Differentiated Services Code-Point
      that may be used for marking packets in a traffic stream.

      In the value set and its semantics, this type is equivalent
      to the Dscp textual convention of the SMIv2.";
    reference 
     "RFC 3289: Management Information Base for the Differentiated
                Services Architecture
      RFC 2474: Definition of the Differentiated Services Field
                (DS Field) in the IPv4 and IPv6 Headers
      RFC 2780: IANA Allocation Guidelines For Values In
                the Internet Protocol and Related Headers";
  }
  
  typedef ipv6-flow-label {
    type uint32 {
      range "0..1048575";
    }
    description
     "The flow-label type represents flow identifier or Flow Label 
      in an IPv6 packet header that may be used to discriminate 
      traffic flows.

      In the value set and its semantics, this type is equivalent
      to the IPv6FlowLabel textual convention of the SMIv2.";
    reference
     "RFC 3595: Textual Conventions for IPv6 Flow Label
      RFC 2460: Internet Protocol, Version 6 (IPv6) Specification";
  }

  typedef port-number {
    type uint16 {
      range "0..65535";
    }
    description
     "The port-number type represents a 16-bit port number of an 
      Internet transport layer protocol such as UDP, TCP, DCCP, or 
      SCTP.  Port numbers are assigned by IANA.  A current list of
      all assignments is available from <http://www.iana.org/>.

      Note that the port number value zero is reserved by IANA.  In
      situations where the value zero does not make sense, it can
      be excluded by subtyping the port-number type.

      In the value set and its semantics, this type is equivalent
      to the InetPortNumber textual convention of the SMIv2.";
    reference
     "RFC  768: User Datagram Protocol
      RFC  793: Transmission Control Protocol
      RFC 4960: Stream Control Transmission Protocol
      RFC 4340: Datagram Congestion Control Protocol (DCCP)
      RFC 4001: Textual Conventions for Internet Network Addresses";
  }

  /*** collection of autonomous system related types ***/

  typedef as-number {
    type uint32;
    description
     "The as-number type represents autonomous system numbers
      which identify an Autonomous System (AS).  An AS is a set
      of routers under a single technical administration, using
      an interior gateway protocol and common metrics to route
      packets within the AS, and using an exterior gateway
      protocol to route packets to other ASs'.  IANA maintains
      the AS number space and has delegated large parts to the
      regional registries.

      Autonomous system numbers were originally limited to 16 
      bits.  BGP extensions have enlarged the autonomous system
      number space to 32 bits.  This type therefore uses an uint32
      base type without a range restriction in order to support
      a larger autonomous system number space.

      In the value set and its semantics, this type is equivalent
      to the InetAutonomousSystemNumber textual convention of 
      the SMIv2.";
    reference
     "RFC 1930: Guidelines for creation, selection, and registration
                of an Autonomous System (AS)
      RFC 4271: A Border Gateway Protocol 4 (BGP-4)
      RFC 4001: Textual Conventions for Internet Network Addresses
      RFC 6793: BGP Support for Four-octet AS Number Space";
  }
  
  /*** collection of IP address and hostname related types ***/

  typedef ip-address {
    type union {
      type inet:ipv4-address;
      type inet:ipv6-address;
    }
    description
     "The ip-address type represents an IP address and is IP 
      version neutral.  The format of the textual representation
      implies the IP version.  This type supports scoped addresses
      by allowing zone identifiers in the address format.";
    reference
     "RFC 4007: IPv6 Scoped Address Architecture";
  }

  typedef ipv4-address {
    type string {
      pattern 
        '(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}'
      +  '([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])'
      + '(%[\p{N}\p{L}]+)?';
    }
    description
      "The ipv4-address type represents an IPv4 address in 
       dotted-quad notation.  The IPv4 address may include a zone
       index, separated by a % sign.

       The zone index is used to disambiguate identical address
       values.  For link-local addresses, the zone index will
       typically be the interface index number or the name of an
       interface.  If the zone index is not present, the default
       zone of the device will be used.

       The canonical format for the zone index is the numerical
       format";
  }

  typedef ipv6-address {
    type string {
      pattern '((:|[0-9a-fA-F]{0,4}):)([0-9a-fA-F]{0,4}:){0,5}'
            + '((([0-9a-fA-F]{0,4}:)?(:|[0-9a-fA-F]{0,4}))|'
            + '(((25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\.){3}'
            + '(25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])))'
            + '(%[\p{N}\p{L}]+)?';
      pattern '(([^:]+:){6}(([^:]+:[^:]+)|(.*\..*)))|'
            + '((([^:]+:)*[^:]+)?::(([^:]+:)*[^:]+)?)'
            + '(%.+)?';
    }
    description
     "The ipv6-address type represents an IPv6 address in full,
      mixed, shortened, and shortened-mixed notation.  The IPv6
      address may include a zone index, separated by a % sign.

      The zone index is used to disambiguate identical address
      values.  For link-local addresses, the zone index will
      typically be the interface index number or the name of an
      interface.  If the zone index is not present, the default
      zone of the device will be used.

      The canonical format of IPv6 addresses uses the compressed
      format described in RFC 4291, Section 2.2, item 2 with the
      following additional rules: the :: substitution must be
      applied to the longest sequence of all-zero 16-bit chunks
      in an IPv6 address.  If there is a tie, the first sequence
      of all-zero 16-bit chunks is replaced by ::.  Single 
      all-zero 16-bit chunks are not compressed.  The canonical
      format uses lowercase characters and leading zeros are
      not allowed.  The canonical format for the zone index is
      the numerical format as described in RFC 4007, Section
      11.2.";
    reference
     "RFC 4291: IP Version 6 Addressing Architecture
      RFC 4007: IPv6 Scoped Address Architecture
      RFC 5952: A Recommendation for IPv6 Address Text
                Representation";
  }

  typedef ip-address-no-zone {
    type union {
      type inet:ipv4-address-no-zone;
      type inet:ipv6-address-no-zone;
    }
    description
     "The ip-address-no-zone type represents an IP address and is 
      IP version neutral.  The format of the textual representation
      implies the IP version.  This type does not support scoped
      addresses since it does not allow zone identifiers in the
      address format.";
    reference
     "RFC 4007: IPv6 Scoped Address Architecture";
  }

  typedef ipv4-address-no-zone {
    type inet:ipv4-address {
      pattern '[\.0-9]*';
    }
    description
      "An IPv4 address without a zone index. This type may be used
       in situations where the zone is known from the context and
       hence no zone index is needed.";
  }

  typedef ipv6-address-no-zone {
    type inet:ipv6-address {
      pattern '[0-9a-fA-F:]*';
    }
    description
      "An IPv6 address without a zone index. This type may be used
       in situations where the zone is known from the context and
       hence no zone index is needed.";
    reference
     "RFC 4291: IP Version 6 Addressing Architecture
      RFC 4007: IPv6 Scoped Address Architecture
      RFC 5952: A Recommendation for IPv6 Address Text
                Representation";
  }

  typedef ip-prefix {
    type union {
      type inet:ipv4-prefix;
      type inet:ipv6-prefix;
    }
    description
     "The ip-prefix type represents an IP prefix and is IP
      version neutral.  The format of the textual representations
      implies the IP version.";
  }

  typedef ipv4-prefix {
    type string {
      pattern
         '(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}'
       +  '([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])'
       + '/(([0-9])|([1-2][0-9])|(3[0-2]))';
    }
    description
     "The ipv4-prefix type represents an IPv4 address prefix.
      The prefix length is given by the number following the
      slash character and must be less than or equal to 32. 

      A prefix length value of n corresponds to an IP address
      mask that has n contiguous 1-bits from the most
      significant bit (MSB) and all other bits set to 0.

      The canonical format of an IPv4 prefix has all bits of
      the IPv4 address set to zero that are not part of the
      IPv4 prefix.";
  }

  typedef ipv6-prefix {
    type string {
      pattern '((:|[0-9a-fA-F]{0,4}):)([0-9a-fA-F]{0,4}:){0,5}'
            + '((([0-9a-fA-F]{0,4}:)?(:|[0-9a-fA-F]{0,4}))|'
            + '(((25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\.){3}'
            + '(25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])))'
            + '(/(([0-9])|([0-9]{2})|(1[0-1][0-9])|(12[0-8])))';
      pattern '(([^:]+:){6}(([^:]+:[^:]+)|(.*\..*)))|'
            + '((([^:]+:)*[^:]+)?::(([^:]+:)*[^:]+)?)'
            + '(/.+)';
    }
    description
     "The ipv6-prefix type represents an IPv6 address prefix.
      The prefix length is given by the number following the
      slash character and must be less than or equal 128. 

      A prefix length value of n corresponds to an IP address
      mask that has n contiguous 1-bits from the most
      significant bit (MSB) and all other bits set to 0.

      The IPv6 address should have all bits that do not belong
      to the prefix set to zero.

      The canonical format of an IPv6 prefix has all bits of
      the IPv6 address set to zero that are not part of the
      IPv6 prefix.  Furthermore, IPv6 address is represented
      in the compressed format described in RFC 4291, Section
      2.2, item 2 with the following additional rules: the :: 
      substitution must be applied to the longest sequence of
      all-zero 16-bit chunks in an IPv6 address.  If there is
      a tie, the first sequence of all-zero 16-bit chunks is
      replaced by ::.  Single all-zero 16-bit chunks are not
      compressed.  The canonical format uses lowercase
      characters and leading zeros are not allowed.";
    reference
     "RFC 4291: IP Version 6 Addressing Architecture";
  }

  /*** collection of domain name and URI types ***/

  typedef domain-name {
    type string {
      pattern 
        '((([a-zA-Z0-9_]([a-zA-Z0-9\-_]){0,61})?[a-zA-Z0-9]\.)*'
      + '([a-zA-Z0-9_]([a-zA-Z0-9\-_]){0,61})?[a-zA-Z0-9]\.?)'
      + '|\.';
      length "1..253";
    }
    description
     "The domain-name type represents a DNS domain name.  The 
      name SHOULD be fully qualified whenever possible.

      Internet domain names are only loosely specified.  Section
      3.5 of RFC 1034 recommends a syntax (modified in Section 
      2.1 of RFC 1123).  The pattern above is intended to allow
      for current practice in domain name use, and some possible
      future expansion.  It is designed to hold various types of
      domain names, including names used for A or AAAA records
      (host names) and other records, such as SRV records.  Note
      that Internet host names have a stricter syntax (described
      in RFC 952) than the DNS recommendations in RFCs 1034 and
      1123, and that systems that want to store host names in
      schema nodes using the domain-name type are recommended to
      adhere to this stricter standard to ensure interoperability.

      The encoding of DNS names in the DNS protocol is limited
      to 255 characters.  Since the encoding consists of labels
      prefixed by a length bytes and there is a trailing NULL
      byte, only 253 characters can appear in the textual dotted
      notation.

      The description clause of schema nodes using the domain-name
      type MUST describe when and how these names are resolved to
      IP addresses.  Note that the resolution of a domain-name value
      may require to query multiple DNS records (e.g., A for IPv4
      and AAAA for IPv6).  The order of the resolution process and
      which DNS record takes precedence can either be defined
      explicitely or it may depend on the configuration of the
      resolver.

      Domain-name values use the US-ASCII encoding.  Their canonical
      format uses lowercase US-ASCII characters.  Internationalized
      domain names MUST be encoded in punycode as described in RFC
      3492";
    reference
     "RFC  952: DoD Internet Host Table Specification
      RFC 1034: Domain Names - Concepts and Facilities
      RFC 1123: Requirements for Internet Hosts -- Application 
                and Support
      RFC 2782: A DNS RR for specifying the location of services
                (DNS SRV)
      RFC 3492: Punycode: A Bootstring encoding of Unicode for
                Internationalized Domain Names in Applications
                (IDNA)
      RFC 5891: Internationalizing Domain Names in Applications
                (IDNA): Protocol";
  }

  typedef host {
    type union {
      type inet:ip-address;
      type inet:domain-name;
    }
    description
     "The host type represents either an IP address or a DNS
      domain name.";
  }

  typedef uri {
    type string;
    description
     "The uri type represents a Uniform Resource Identifier
      (URI) as defined by STD 66.

      Objects using the uri type MUST be in US-ASCII encoding,
      and MUST be normalized as described by RFC 3986 Sections
      6.2.1, 6.2.2.1, and 6.2.2.2.  All unnecessary
      percent-encoding is removed, and all case-insensitive
      characters are set to lowercase except for hexadecimal
      digits, which are normalized to uppercase as described in
      Section 6.2.2.1.

      The purpose of this normalization is to help provide
      unique URIs.  Note that this normalization is not
      sufficient to provide uniqueness.  Two URIs that are
      textually distinct after this normalization may still be
      equivalent.

      Objects using the uri type may restrict the schemes that
      they permit.  For example, 'data:' and 'urn:' schemes
      might not be appropriate.

      A zero-length URI is not a valid URI.  This can be used to
      express 'URI absent' where required.

      In the value set and its semantics, this type is equivalent
      to the Uri SMIv2 textual convention defined in RFC 5017.";
    reference
     "RFC 3986: Uniform Resource Identifier (URI): Generic Syntax
      RFC 3305: Report from the Joint W3C/IETF URI Planning Interest
                Group: Uniform Resource Identifiers (URIs), URLs, 
                and Uniform Resource Names (URNs): Clarifications
                and Recommendations
      RFC 5017: MIB Textual Conventions for Uniform Resource 
                Identifiers (URIs)";
  }

}
	    

<CODE ENDS>

5. IANA Considerations

This document registers two URIs in the IETF XML registry [RFC3688]. Following the format in RFC 3688, the following registrations have been made.

  URI: urn:ietf:params:xml:ns:yang:ietf-yang-types

  Registrant Contact: The NETMOD WG of the IETF.

  XML: N/A, the requested URI is an XML namespace.

  URI: urn:ietf:params:xml:ns:yang:ietf-inet-types

  Registrant Contact: The NETMOD WG of the IETF.

  XML: N/A, the requested URI is an XML namespace.
	    

This document registers two YANG modules in the YANG Module Names registry [RFC6020].

  name:         ietf-yang-types
  namespace:    urn:ietf:params:xml:ns:yang:ietf-yang-types
  prefix:       yang
  reference:    RFC 6021

  name:         ietf-inet-types
  namespace:    urn:ietf:params:xml:ns:yang:ietf-inet-types
  prefix:       inet
  reference:    RFC 6021
	    

6. Security Considerations

This document defines common data types using the YANG data modeling language. The definitions themselves have no security impact on the Internet but the usage of these definitions in concrete YANG modules might have. The security considerations spelled out in the YANG specification [RFC6020] apply for this document as well.

7. Contributors

The following people contributed significantly to the initial version of this document:

 - Andy Bierman (Brocade)
 - Martin Bjorklund (Tail-f Systems)
 - Balazs Lengyel (Ericsson)
 - David Partain (Ericsson)
 - Phil Shafer (Juniper Networks)
	    

8. Acknowledgments

The editor wishes to thank the following individuals for providing helpful comments on various versions of this document: Andy Bierman, Martin Bjorklund, Ladislav Lhotka, Lars-Johan Liman, and Dan Romascanu.

Juergen Schoenwaelder was partly funded by Flamingo, a Network of Excellence project (ICT-318488) supported by the European Commission under its Seventh Framework Programme.

9. References

9.1. Normative References

[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2010.
[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.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet: Timestamps", RFC 3339, July 2002.
[XPATH] Clark, J. and S. DeRose, "XML Path Language (XPath) Version 1.0", World Wide Web Consortium Recommendation REC-xpath-19991116, November 1999.
[RFC3986] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005.
[RFC3492] Costello, A., "Punycode: A Bootstring encoding of Unicode for Internationalized Domain Names in Applications (IDNA)", RFC 3492, March 2003.
[RFC4122] Leach, P., Mealling, M. and R. Salz, "A Universally Unique IDentifier (UUID) URN Namespace", RFC 4122, July 2005.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, February 2006.
[RFC4007] Deering, S., Haberman, B., Jinmei, T., Nordmark, E. and B. Zill, "IPv6 Scoped Address Architecture", RFC 4007, March 2005.

9.2. Informative References

[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "NETCONF Configuration Protocol (NETCONF)", RFC 6241, June 2011.
[RFC6021] Schoenwaelder, J., "Common YANG Data Types", RFC 6021, October 2010.
[RFC2578] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.
[RFC2579] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Textual Conventions for SMIv2", STD 58, RFC 2579, April 1999.
[RFC2856] Bierman, A., McCloghrie, K. and R. Presuhn, "Textual Conventions for Additional High Capacity Data Types", RFC 2856, June 2000.
[RFC4502] Waldbusser, S., "Remote Network Monitoring Management Information Base Version 2", RFC 4502, May 2006.
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, August 1980.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1981.
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, RFC 793, September 1981.
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities", STD 13, RFC 1034, November 1987.
[RFC1123] Braden, R., "Requirements for Internet Hosts - Application and Support", STD 3, RFC 1123, October 1989.
[RFC5891] Klensin, J., "Internationalizing Domain Names in Applications (IDNA): Protocol", RFC 5891, August 2010.
[RFC1930] Hawkinson, J. and T. Bates, "Guidelines for creation, selection, and registration of an Autonomous System (AS)", BCP 6, RFC 1930, March 1996.
[RFC2460] Deering, S.E. and R.M. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998.
[RFC2474] Nichols, K., Blake, S., Baker, F. and D.L. Black, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers", RFC 2474, December 1998.
[RFC2780] Bradner, S. and V. Paxson, "IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers", BCP 37, RFC 2780, March 2000.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol", RFC 4960, September 2007.
[RFC3289] Baker, F., Chan, K. and A. Smith, "Management Information Base for the Differentiated Services Architecture", RFC 3289, May 2002.
[RFC3305] Mealling, M. and R. Denenberg, "Report from the Joint W3C/IETF URI Planning Interest Group: Uniform Resource Identifiers (URIs), URLs, and Uniform Resource Names (URNs): Clarifications and Recommendations", RFC 3305, August 2002.
[RFC3595] Wijnen, B., "Textual Conventions for IPv6 Flow Label", RFC 3595, September 2003.
[RFC4001] Daniele, M., Haberman, B., Routhier, S. and J. Schoenwaelder, "Textual Conventions for Internet Network Addresses", RFC 4001, February 2005.
[RFC4271] Rekhter, Y., Li, T. and S. Hares, "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet Autonomous System (AS) Number Space", RFC 6793, December 2012.
[RFC4340] Kohler, E., Handley, M. and S. Floyd, "Datagram Congestion Control Protocol (DCCP)", RFC 4340, March 2006.
[RFC5017] McWalter, D., "MIB Textual Conventions for Uniform Resource Identifiers (URIs)", RFC 5017, September 2007.
[RFC0952] Harrenstien, K., Stahl, M. and E. Feinler, "DoD Internet host table specification", RFC 952, October 1985.
[IEEE802] IEEE, "IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture", IEEE Std. 802-2001,
[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6 Address Text Representation", RFC 5952, August 2010.
[RFC2782] Gulbrandsen, A., Vixie, P. and L. Esibov, "A DNS RR for specifying the location of services (DNS SRV)", RFC 2782, February 2000.
[XSD-TYPES] Malhotra, A. and P. Biron, "XML Schema Part 2: Datatypes Second Edition", World Wide Web Consortium Recommendation REC-xmlschema-2-20041028, October 2004.
[ISO9834-1] ISO/IEC, "Information technology -- Open Systems Interconnection -- Procedures for the operation of OSI Registration Authorities: General procedures and top arcs of the ASN.1 Object Identifier tree ", ISO/IEC 9834-1:2008, 2008.

Appendix A. Changes from RFC 6021

This version adds new type definitions to the YANG modules. The following new data types have been added to the ietf-yang-types module:

  • yang-identifier
  • hex-string
  • uuid
  • dotted-quad

The following new data types have been added to the ietf-inet-types module:

  • ip-address-no-zone
  • ipv4-address-no-zone
  • ipv6-address-no-zone

Author's Address

Juergen Schoenwaelder (editor) Jacobs University EMail: j.schoenwaelder@jacobs-university.de