RFC6021

Internet Engineering Task Force (IETF) J. Schoenwaelder, Ed. Request for Comments: 6021 Jacobs University Category: Standards Track October 2010 ISSN: 2070-1721

                     Common YANG Data Types

Abstract

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

Status of This Memo

This is an Internet Standards Track document.

This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741.

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc6021.

Copyright Notice

Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

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

Introduction

YANG [[[RFC6020]]] is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF) [[[RFC4741]]]. 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 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.

The derived types are generally designed to be applicable for modeling all areas of management information.

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]]].

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              |
    | date-and-time         | -                              |
    | timeticks             | TimeTicks (SNMPv2-SMI)         |
    | timestamp             | TimeStamp (SNMPv2-TC)          |
    | phys-address          | PhysAddress (SNMPv2-TC)        |
    | mac-address           | MacAddress (SNMPv2-TC)         |
    | xpath1.0              | -                              |
    +-----------------------+--------------------------------+

                              Table 1

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-prefix       | -                                             |
| ipv4-prefix     | -                                             |
| ipv6-prefix     | -                                             |
| domain-name     | -                                             |
| host            | -                                             |
| uri             | Uri (URI-TC-MIB)                              |
+-----------------+-----------------------------------------------+

                              Table 2

Core YANG Derived Types

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

file "[email protected]"

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:[email protected]>

 WG Chair: David Partain
           <mailto:[email protected]>

 WG Chair: David Kessens
           <mailto:[email protected]>

 Editor:   Juergen Schoenwaelder
           <mailto:[email protected]>";

description

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

 Copyright (c) 2010 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 6021; see
 the RFC itself for full legal notices.";

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)";

}

/*** 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";

}

}

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]]], [[[RFC4893]]], [[[RFC4960]]], [[[RFC5017]]], [[[RFC5891]]], and [[[RFC5952]]].

file "[email protected]"

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:[email protected]>

 WG Chair: David Partain
           <mailto:[email protected]>

 WG Chair: David Kessens
           <mailto:[email protected]>

 Editor:   Juergen Schoenwaelder
           <mailto:[email protected]>";

description

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

 Copyright (c) 2010 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 6021; see
 the RFC itself for full legal notices.";

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 4893: BGP Support for Four-octet AS Number Space
   RFC 4001: Textual Conventions for Internet Network Addresses";

}

/*** 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 representations
   implies the IP version.";

}

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-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)";

}

}

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

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.

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)

Acknowledgments

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

References

Normative References

[[[RFC2119]]] Bradner, S., "Key words for use in RFCs to Indicate

            Requirement Levels", BCP 14, RFC 2119, March 1997.

[[[RFC3339]]] Klyne, G., Ed. and C. Newman, "Date and Time on the

            Internet: Timestamps", RFC 3339, July 2002.

[[[RFC3492]]] Costello, A., "Punycode: A Bootstring encoding of

            Unicode for Internationalized Domain Names in
            Applications (IDNA)", RFC 3492, March 2003.

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

            January 2004.

[[[RFC3986]]] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform

            Resource Identifier (URI): Generic Syntax", STD 66,
            RFC 3986, January 2005.

[[[RFC4007]]] Deering, S., Haberman, B., Jinmei, T., Nordmark, E., and

            B. Zill, "IPv6 Scoped Address Architecture", RFC 4007,
            March 2005.

[[[RFC4291]]] Hinden, R. and S. Deering, "IP Version 6 Addressing

            Architecture", RFC 4291, February 2006.

[[[RFC6020]]] Bjorklund, M., Ed., "YANG - A Data Modeling Language for

            Network Configuration Protocol (NETCONF)", RFC 6020,
            October 2010.

[XPATH] Clark, J. and S. DeRose, "XML Path Language (XPath)

            Version 1.0", World Wide Web Consortium
            Recommendation REC-xpath-19991116, November 1999,
            <http://www.w3.org/TR/1999/REC-xpath-19991116>.

Informative References

[IEEE802] IEEE, "IEEE Standard for Local and Metropolitan Area

            Networks: Overview and Architecture", IEEE Std. 802-
            2001.

[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.

[[[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.

[[[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.

[[[RFC1123]]] Braden, R., "Requirements for Internet Hosts -

            Application and Support", STD 3, RFC 1123, October 1989.

[[[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. and R. Hinden, "Internet Protocol, Version 6

            (IPv6) Specification", RFC 2460, December 1998.

[[[RFC2474]]] Nichols, K., Blake, S., Baker, F., and D. Black,

            "Definition of the Differentiated Services Field (DS
            Field) in the IPv4 and IPv6 Headers", RFC 2474,
            December 1998.

[[[RFC2578]]] McCloghrie, K., Ed., Perkins, D., Ed., and J.

            Schoenwaelder, Ed., "Structure of Management Information
            Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.

[[[RFC2579]]] McCloghrie, K., Ed., Perkins, D., Ed., and J.

            Schoenwaelder, Ed., "Textual Conventions for SMIv2",
            STD 58, RFC 2579, April 1999.

[[[RFC2780]]] Bradner, S. and V. Paxson, "IANA Allocation Guidelines

            For Values In the Internet Protocol and Related
            Headers", BCP 37, RFC 2780, March 2000.

[[[RFC2782]]] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for

            specifying the location of services (DNS SRV)",
            RFC 2782, February 2000.

[[[RFC2856]]] Bierman, A., McCloghrie, K., and R. Presuhn, "Textual

            Conventions for Additional High Capacity Data Types",
            RFC 2856, June 2000.

[[[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.

[[[RFC4340]]] Kohler, E., Handley, M., and S. Floyd, "Datagram

            Congestion Control Protocol (DCCP)", RFC 4340,
            March 2006.

[[[RFC4502]]] Waldbusser, S., "Remote Network Monitoring Management

            Information Base Version 2", RFC 4502, May 2006.

[[[RFC4741]]] Enns, R., "NETCONF Configuration Protocol", RFC 4741,

            December 2006.

[[[RFC4893]]] Vohra, Q. and E. Chen, "BGP Support for Four-octet AS

            Number Space", RFC 4893, May 2007.

[[[RFC4960]]] Stewart, R., "Stream Control Transmission Protocol",

            RFC 4960, September 2007.

[[[RFC5017]]] McWalter, D., "MIB Textual Conventions for Uniform

            Resource Identifiers (URIs)", RFC 5017, September 2007.

[[[RFC5891]]] Klensin, J., "Internationalizing Domain Names in

            Applications (IDNA): Protocol", RFC 5891, August 2010.

[[[RFC5952]]] Kawamura, S. and M. Kawashima, "A Recommendation for

            IPv6 Address Text Representation", RFC 5952,
            August 2010.

[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,
            <http://www.w3.org/TR/2004/REC-xmlschema-2-20041028>.

Author's Address

Juergen Schoenwaelder (editor) Jacobs University

EMail: [email protected]