GENWiki

Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools

Problem, Formatting or Query -  Send Feedback

Was this page helpful?-10+1


rfc:rfc3291

Network Working Group M. Daniele Request for Comments: 3291 Consultant Obsoletes: 2851 B. Haberman Category: Standards Track Consultant

                                                           S. Routhier
                                              Wind River Systems, Inc.
                                                      J. Schoenwaelder
                                                       TU Braunschweig
                                                              May 2002
         Textual Conventions for Internet Network Addresses

Status of this Memo

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

Copyright Notice

 Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

 This MIB module defines textual conventions to represent commonly
 used Internet network layer addressing information.  The intent is
 that these textual conventions (TCs) will be imported and used in MIB
 modules that would otherwise define their own representations.
 This document obsoletes RFC 2851.

Daniele, et. al. Standards Track [Page 1] RFC 3291 TCs for Internet Network Addresses May 2002

Table of Contents

 1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  2
 2.  The SNMP Management Framework  . . . . . . . . . . . . . . . .  4
 3.  Definitions  . . . . . . . . . . . . . . . . . . . . . . . . .  5
 4.  Usage Hints  . . . . . . . . . . . . . . . . . . . . . . . . . 11
 4.1 Table Indexing . . . . . . . . . . . . . . . . . . . . . . . . 12
 4.2 Uniqueness of Addresses  . . . . . . . . . . . . . . . . . . . 12
 4.3 Multiple Addresses per Host  . . . . . . . . . . . . . . . . . 13
 4.4 Resolving DNS Names  . . . . . . . . . . . . . . . . . . . . . 13
 5.  Table Indexing Example . . . . . . . . . . . . . . . . . . . . 13
 6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 16
 7.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 16
 8.  Intellectual Property Notice . . . . . . . . . . . . . . . . . 16
 9.  Changes from RFC 2851  . . . . . . . . . . . . . . . . . . . . 16
 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 20

1. Introduction

 Several standards-track MIB modules use the IpAddress SMIv2 base
 type.  This limits the applicability of these MIB modules to IP
 Version 4 (IPv4) since the IpAddress SMIv2 base type can only contain
 4 byte IPv4 addresses.  The IpAddress SMIv2 base type has become
 problematic with the introduction of IP Version 6 (IPv6) addresses
 [19].
 This document defines multiple textual conventions as a mechanism to
 express generic Internet network layer addresses within MIB module
 specifications.  The solution is compatible with SMIv2 (STD 58) and
 SMIv1 (STD 16).  New MIB definitions which need to express network
 layer Internet addresses SHOULD use the textual conventions defined
 in this memo.  New MIB modules SHOULD NOT use the SMIv2 IpAddress
 base type anymore.
 A generic Internet address consists of two objects, one whose syntax
 is InetAddressType, and another whose syntax is InetAddress.  The
 value of the first object determines how the value of the second
 object is encoded.  The InetAddress textual convention represents an
 opaque Internet address value.  The InetAddressType enumeration is
 used to "cast" the InetAddress value into a concrete textual
 convention for the address type.  This usage of multiple textual
 conventions allows expression of the display characteristics of each
 address type and makes the set of defined Internet address types
 extensible.

Daniele, et. al. Standards Track [Page 2] RFC 3291 TCs for Internet Network Addresses May 2002

 The textual conventions defined in this document can also be used to
 represent generic Internet subnets and Internet address ranges.  A
 generic Internet subnet is represented by three objects, one whose
 syntax is InetAddressType, a second one whose syntax is InetAddress
 and a third one whose syntax is InetAddressPrefixLength.  The
 InetAddressType value again determines the concrete format of the
 InetAddress value while the InetAddressPrefixLength identifies the
 Internet network address prefix.
 A generic range of consecutive Internet addresses is represented by
 three objects.  The first one has the syntax InetAddressType while
 the remaining objects have the syntax InetAddress and specify the
 start and end of the address range.  The InetAddressType value again
 determines the format of the InetAddress values.
 The textual conventions defined in this document can be used to
 define Internet addresses by using DNS domain names in addition to
 IPv4 and IPv6 addresses.  A MIB designer can write compliance
 statements to express that only a subset of the possible address
 types must be supported by a compliant implementation.
 MIB developers who need to represent Internet addresses SHOULD use
 these definitions whenever applicable, as opposed to defining their
 own constructs.  Even MIB modules that only need to represent IPv4 or
 IPv6 addresses SHOULD use the InetAddressType/InetAddress textual
 conventions defined in this memo.
 There are many widely deployed MIB modules that use IPv4 addresses
 and which need to be revised to support IPv6.  These MIBs can be
 categorized as follows:
 1. MIB modules which define management information that is in
    principle IP version neutral, but the MIB currently uses
    addressing constructs specific to a certain IP version.
 2. MIB modules which define management information that is specific
    to particular IP version (either IPv4 or IPv6) and which is very
    unlikely to ever be applicable to another IP version.
 MIB modules of the first type SHOULD provide object definitions
 (e.g., tables) that work with all versions of IP.  In particular,
 when revising a MIB module which contains IPv4 specific tables, it is
 suggested to define new tables using the textual conventions defined
 in this memo which support all versions of IP.  The status of the new
 tables SHOULD be "current" while the status of the old IP version
 specific tables SHOULD be changed to "deprecated".  The other
 approach of having multiple similar tables for different IP versions
 is strongly discouraged.

Daniele, et. al. Standards Track [Page 3] RFC 3291 TCs for Internet Network Addresses May 2002

 MIB modules of the second type, which are inherently IP version
 specific, do not need to be redefined.  Note that even in this case,
 any additions to these MIB modules or new IP version specific MIB
 modules SHOULD use the textual conventions defined in this memo.
 MIB developers SHOULD NOT use the textual conventions defined in this
 document to represent generic transport layer addresses.  Instead the
 SMIv2 TAddress textual convention and associated definitions should
 be used for transport layer addresses.
 The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT" and "MAY" in
 this document are to be interpreted as described in RFC 2119 [1].

2. The SNMP Management Framework

 The SNMP Management Framework presently consists of five major
 components:
 o  An overall architecture, described in RFC 2571 [2].
 o  Mechanisms for describing and naming objects and events for the
    purpose of management.  The first version of this Structure of
    Management Information (SMI) is called SMIv1 and described in STD
    16, RFC 1155 [3], STD 16, RFC 1212 [4] and RFC 1215 [5].  The
    second version, called SMIv2, is described in STD 58, RFC 2578
    [6], STD 58, RFC 2579 [7] and STD 58, RFC 2580 [8].
 o  Message protocols for transferring management information.  The
    first version of the SNMP message protocol is called SNMPv1 and
    described in STD 15, RFC 1157 [9].  A second version of the SNMP
    message protocol, which is not an Internet standards track
    protocol, is called SNMPv2c and described in RFC 1901 [10] and RFC
    1906 [11].  The third version of the message protocol is called
    SNMPv3 and described in RFC 1906 [11], RFC 2572 [12] and RFC 2574
    [13].
 o  Protocol operations for accessing management information.  The
    first set of protocol operations and associated PDU formats is
    described in STD 15, RFC 1157 [9].  A second set of protocol
    operations and associated PDU formats is described in RFC 1905
    [14].
 o  A set of fundamental applications described in RFC 2573 [15] and
    the view-based access control mechanism described in RFC 2575
    [16].
 A more detailed introduction to the current SNMP Management Framework
 can be found in RFC 2570 [17].

Daniele, et. al. Standards Track [Page 4] RFC 3291 TCs for Internet Network Addresses May 2002

 Managed objects are accessed via a virtual information store, termed
 the Management Information Base or MIB.  Objects in the MIB are
 defined using the mechanisms defined in the SMI.
 This memo specifies a MIB module that is compliant to the SMIv2.  A
 MIB conforming to the SMIv1 can be produced through the appropriate
 translations.  The resulting translated MIB must be semantically
 equivalent, except where objects or events are omitted because no
 translation is possible (use of Counter64).  Some machine readable
 information in SMIv2 will be converted into textual descriptions in
 SMIv1 during the translation process.  However, this loss of machine
 readable information is not considered to change the semantics of the
 MIB.

3. Definitions

INET-ADDRESS-MIB DEFINITIONS ::= BEGIN

IMPORTS

  MODULE-IDENTITY, mib-2, Unsigned32 FROM SNMPv2-SMI
  TEXTUAL-CONVENTION                 FROM SNMPv2-TC;

inetAddressMIB MODULE-IDENTITY

  LAST-UPDATED "200205090000Z"
  ORGANIZATION
      "IETF Operations and Management Area"
  CONTACT-INFO
      "Juergen Schoenwaelder (Editor)
       TU Braunschweig
       Bueltenweg 74/75
       38106 Braunschweig, Germany
       Phone: +49 531 391-3289
       EMail: schoenw@ibr.cs.tu-bs.de
       Send comments to <mibs@ops.ietf.org>."
  DESCRIPTION
      "This MIB module defines textual conventions for
       representing Internet addresses. An Internet
       address can be an IPv4 address, an IPv6 address
       or a DNS domain name. This module also defines
       textual conventions for Internet port numbers,
       autonomous system numbers and the length of an
       Internet address prefix."
  REVISION     "200205090000Z"
  DESCRIPTION
      "Second version, published as RFC 3291. This
       revisions contains several clarifications and it

Daniele, et. al. Standards Track [Page 5] RFC 3291 TCs for Internet Network Addresses May 2002

       introduces several new textual conventions:
       InetAddressPrefixLength, InetPortNumber,
       InetAutonomousSystemNumber, InetAddressIPv4z,
       and InetAddressIPv6z."
  REVISION     "200006080000Z"
  DESCRIPTION
      "Initial version, published as RFC 2851."
  ::= { mib-2 76 }

InetAddressType ::= TEXTUAL-CONVENTION

  STATUS      current
  DESCRIPTION
      "A value that represents a type of Internet address.
       unknown(0)  An unknown address type. This value MUST
                   be used if the value of the corresponding
                   InetAddress object is a zero-length string.
                   It may also be used to indicate an IP address
                   which is not in one of the formats defined
                   below.
       ipv4(1)     An IPv4 address as defined by the
                   InetAddressIPv4 textual convention.
       ipv6(2)     A global IPv6 address as defined by the
                   InetAddressIPv6 textual convention.
       ipv4z(3)    A non-global IPv4 address including a zone
                   index as defined by the InetAddressIPv4z
                   textual convention.
       ipv6z(4)    A non-global IPv6 address including a zone
                   index as defined by the InetAddressIPv6z
                   textual convention.
       dns(16)     A DNS domain name as defined by the
                   InetAddressDNS textual convention.
       Each definition of a concrete InetAddressType value must be
       accompanied by a definition of a textual convention for use
       with that InetAddressType.
       To support future extensions, the InetAddressType textual
       convention SHOULD NOT be sub-typed in object type definitions.
       It MAY be sub-typed in compliance statements in order to
       require only a subset of these address types for a compliant
       implementation.
       Implementations must ensure that InetAddressType objects

Daniele, et. al. Standards Track [Page 6] RFC 3291 TCs for Internet Network Addresses May 2002

       and any dependent objects (e.g. InetAddress objects) are
       consistent.  An inconsistentValue error must be generated
       if an attempt to change an InetAddressType object would,
       for example, lead to an undefined InetAddress value.  In
       particular, InetAddressType/InetAddress pairs must be
       changed together if the address type changes (e.g. from
       ipv6(2) to ipv4(1))."
  SYNTAX      INTEGER {
                  unknown(0),
                  ipv4(1),
                  ipv6(2),
                  ipv4z(3),
                  ipv6z(4),
                  dns(16)
              }

InetAddress ::= TEXTUAL-CONVENTION

  STATUS      current
  DESCRIPTION
      "Denotes a generic Internet address.
       An InetAddress value is always interpreted within the context
       of an InetAddressType value. Every usage of the InetAddress
       textual convention is required to specify the InetAddressType
       object which provides the context.  It is suggested that the
       InetAddressType object is logically registered before the
       object(s) which use the InetAddress textual convention if
       they appear in the same logical row.
       The value of an InetAddress object must always be
       consistent with the value of the associated InetAddressType
       object. Attempts to set an InetAddress object to a value
       which is inconsistent with the associated InetAddressType
       must fail with an inconsistentValue error.
       When this textual convention is used as the syntax of an
       index object, there may be issues with the limit of 128
       sub-identifiers specified in SMIv2, STD 58. In this case,
       the object definition MUST include a 'SIZE' clause to
       limit the number of potential instance sub-identifiers."
  SYNTAX      OCTET STRING (SIZE (0..255))

InetAddressIPv4 ::= TEXTUAL-CONVENTION

  DISPLAY-HINT "1d.1d.1d.1d"
  STATUS       current
  DESCRIPTION
      "Represents an IPv4 network address:

Daniele, et. al. Standards Track [Page 7] RFC 3291 TCs for Internet Network Addresses May 2002

         octets   contents         encoding
          1-4     IPv4 address     network-byte order
       The corresponding InetAddressType value is ipv4(1).
       This textual convention SHOULD NOT be used directly in object
       definitions since it restricts addresses to a specific format.
       However, if it is used, it MAY be used either on its own or in
       conjunction with InetAddressType as a pair."
  SYNTAX       OCTET STRING (SIZE (4))

InetAddressIPv6 ::= TEXTUAL-CONVENTION

  DISPLAY-HINT "2x:2x:2x:2x:2x:2x:2x:2x"
  STATUS       current
  DESCRIPTION
      "Represents an IPv6 network address:
         octets   contents         encoding
          1-16    IPv6 address     network-byte order
       The corresponding InetAddressType value is ipv6(2).
       This textual convention SHOULD NOT be used directly in object
       definitions since it restricts addresses to a specific format.
       However, if it is used, it MAY be used either on its own or in
       conjunction with InetAddressType as a pair."
  SYNTAX       OCTET STRING (SIZE (16))

InetAddressIPv4z ::= TEXTUAL-CONVENTION

  DISPLAY-HINT "1d.1d.1d.1d%4d"
  STATUS       current
  DESCRIPTION
      "Represents a non-global IPv4 network address together
       with its zone index:
         octets   contents         encoding
          1-4     IPv4 address     network-byte order
          5-8     zone index       network-byte order
       The corresponding InetAddressType value is ipv4z(3).
       The zone index (bytes 5-8) is used to disambiguate identical
       address values on nodes which have interfaces attached to
       different zones of the same scope. The zone index may contain
       the special value 0 which refers to the default zone for each
       scope.
       This textual convention SHOULD NOT be used directly in object

Daniele, et. al. Standards Track [Page 8] RFC 3291 TCs for Internet Network Addresses May 2002

       definitions since it restricts addresses to a specific format.
       However, if it is used, it MAY be used either on its own or in
       conjunction with InetAddressType as a pair."
  SYNTAX OCTET STRING (SIZE (8))

InetAddressIPv6z ::= TEXTUAL-CONVENTION

  DISPLAY-HINT "2x:2x:2x:2x:2x:2x:2x:2x%4d"
  STATUS       current
  DESCRIPTION
      "Represents a non-global IPv6 network address together
       with its zone index:
         octets   contents         encoding
          1-16    IPv6 address     network-byte order
         17-20    zone index       network-byte order
       The corresponding InetAddressType value is ipv6z(4).
       The zone index (bytes 17-20) is used to disambiguate
       identical address values on nodes which have interfaces
       attached to different zones of the same scope. The zone index
       may contain the special value 0 which refers to the default
       zone for each scope.
       This textual convention SHOULD NOT be used directly in object
       definitions since it restricts addresses to a specific format.
       However, if it is used, it MAY be used either on its own or in
       conjunction with InetAddressType as a pair."
  SYNTAX OCTET STRING (SIZE (20))

InetAddressDNS ::= TEXTUAL-CONVENTION

  DISPLAY-HINT "255a"
  STATUS       current
  DESCRIPTION
      "Represents a DNS domain name. The name SHOULD be fully
       qualified whenever possible.
       The corresponding InetAddressType is dns(16).
       The DESCRIPTION clause of InetAddress objects that may have
       InetAddressDNS values must fully describe how (and when) such
       names are to be resolved to IP addresses.
       This textual convention SHOULD NOT be used directly in object
       definitions since it restricts addresses to a specific format.
       However, if it is used, it MAY be used either on its own or in
       conjunction with InetAddressType as a pair."
  SYNTAX       OCTET STRING (SIZE (1..255))

Daniele, et. al. Standards Track [Page 9] RFC 3291 TCs for Internet Network Addresses May 2002

InetAddressPrefixLength ::= TEXTUAL-CONVENTION

  STATUS      current
  DESCRIPTION
      "Denotes the length of a generic Internet network address
       prefix. A value of n corresponds to an IP address mask
       which has n contiguous 1-bits from the most significant
       bit (MSB) and all other bits set to 0.
       An InetAddressPrefixLength value is always interpreted within
       the context of an InetAddressType value. Every usage of the
       InetAddressPrefixLength textual convention is required to
       specify the InetAddressType object which provides the
       context.  It is suggested that the InetAddressType object is
       logically registered before the object(s) which use the
       InetAddressPrefixLength textual convention if they appear in
       the same logical row.
       InetAddressPrefixLength values that are larger than
       the maximum length of an IP address for a specific
       InetAddressType are treated as the maximum significant
       value applicable for the InetAddressType. The maximum
       significant value is 32 for the InetAddressType
       'ipv4(1)' and 'ipv4z(3)' and 128 for the InetAddressType
       'ipv6(2)' and 'ipv6z(4)'. The maximum significant value
       for the InetAddressType 'dns(16)' is 0.
       The value zero is object-specific and must be defined as
       part of the description of any object which uses this
       syntax. Examples of the usage of zero might include
       situations where the Internet network address prefix
       is unknown or does not apply."
  SYNTAX      Unsigned32

InetPortNumber ::= TEXTUAL-CONVENTION

  STATUS      current
  DESCRIPTION
      "Represents a 16 bit port number of an Internet transport
       layer protocol. Port numbers are assigned by IANA. A
       current list of all assignments is available from
       <http://www.iana.org/>.
       The value zero is object-specific and must be defined as
       part of the description of any object which uses this
       syntax. Examples of the usage of zero might include
       situations where a port number is unknown, or when the
       value zero is used as a wildcard in a filter."
  REFERENCE  "STD 6 (RFC 768), STD 7 (RFC 793) and RFC 2960"
  SYNTAX      Unsigned32 (0..65535)

Daniele, et. al. Standards Track [Page 10] RFC 3291 TCs for Internet Network Addresses May 2002

InetAutonomousSystemNumber ::= TEXTUAL-CONVENTION

  STATUS      current
  DESCRIPTION
      "Represents an autonomous system number which identifies 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 are currently limited to 16 bits
       (0..65535). There is however work in progress to enlarge the
       autonomous system number space to 32 bits. This textual
       convention therefore uses an Unsigned32 value without a
       range restriction in order to support a larger autonomous
       system number space."
  REFERENCE  "RFC 1771, RFC 1930"
  SYNTAX      Unsigned32

END

4. Usage Hints

 The InetAddressType and InetAddress textual conventions have been
 introduced to avoid over-constraining an object definition by the use
 of the IpAddress SMI base type which is IPv4 specific.  An
 InetAddressType/InetAddress pair can represent IP addresses in
 various formats.
 The InetAddressType and InetAddress objects SHOULD NOT be sub-typed
 in object definitions.  Sub-typing binds the MIB module to specific
 address formats, which may cause serious problems if new address
 formats need to be introduced.  Note that it is possible to write
 compliance statements in order to express that only a subset of the
 defined address types must be implemented to be compliant.
 Every usage of the InetAddress or InetAddressPrefixLength textual
 conventions must specify which InetAddressType object provides the
 context for the interpretation of the InetAddress or
 InetAddressPrefixLength textual convention.
 It is suggested that the InetAddressType object is logically
 registered before the object(s) which uses the InetAddress or
 InetAddressPrefixLength textual convention.  An InetAddressType
 object is logically registered before an InetAddress or
 InetAddressPrefixLength object if it appears before the InetAddress
 or InetAddressPrefixLength object in the conceptual row (which

Daniele, et. al. Standards Track [Page 11] RFC 3291 TCs for Internet Network Addresses May 2002

 includes any index objects).  This rule allows programs such as MIB
 compilers to identify the InetAddressType of a given InetAddress or
 InetAddressPrefixLength object by searching for the InetAddressType
 object which precedes an InetAddress or InetAddressPrefixLength
 object.

4.1 Table Indexing

 When a generic Internet address is used as an index, both the
 InetAddressType and InetAddress objects MUST be used.  The
 InetAddressType object MUST be listed before the InetAddress object
 in the INDEX clause.
 The IMPLIED keyword MUST NOT be used for an object of type
 InetAddress in an INDEX clause.  Instance sub-identifiers are then of
 the form T.N.O1.O2...On, where T is the value of the InetAddressType
 object, O1...On are the octets in the InetAddress object, and N is
 the number of those octets.
 There is a meaningful lexicographical ordering to tables indexed in
 this fashion.  Command generator applications may lookup specific
 addresses of known type and value, issue GetNext requests for
 addresses of a single type, or issue GetNext requests for a specific
 type and address prefix.

4.2 Uniqueness of Addresses

 IPv4 addresses were intended to be globally unique, current usage
 notwithstanding.  IPv6 addresses were architected to have different
 scopes and hence uniqueness [19].  In particular, IPv6 "link-local"
 and "site-local" addresses are not guaranteed to be unique on any
 particular node.  In such cases, the duplicate addresses must be
 configured on different interfaces.  So the combination of an IPv6
 address and a zone index is unique [21].
 The InetAddressIPv6 textual convention has been defined to represent
 global IPv6 addresses and non-global IPv6 addresses in cases where no
 zone index is needed (e.g., on end hosts with a single interface).
 The InetAddressIPv6z textual convention has been defined to represent
 non-global IPv6 addresses in cases where a zone index is needed
 (e.g., a router connecting multiple zones).  MIB designers who use
 InetAddressType/InetAddress pairs therefore do not need to define
 additional objects in order to support non-global addresses on nodes
 that connect multiple zones.
 The InetAddressIPv4z is intended for use in MIBs (like the TCP-MIB)
 which report addresses in the address family used on the wire, but
 where the entity instrumented obtains such addresses from

Daniele, et. al. Standards Track [Page 12] RFC 3291 TCs for Internet Network Addresses May 2002

 applications or administrators in a form which includes a zone index,
 such as v4-mapped IPv6 addresses.
 The size of the zone index has been chosen so that it is consistent
 with (i) the numerical zone index defined in [21] and (ii) the
 sin6_scope_id field of the sockaddr_in6 structure defined in RFC 2553
 [20].

4.3 Multiple Addresses per Host

 A single host system may be configured with multiple addresses (IPv4
 or IPv6), and possibly with multiple DNS names.  Thus it is possible
 for a single host system to be accessible by multiple
 InetAddressType/InetAddress pairs.
 If this could be an implementation or usage issue, the DESCRIPTION
 clause of the relevant objects must fully describe which address is
 reported in a given InetAddressType/InetAddress pair.

4.4 Resolving DNS Names

 DNS names MUST be resolved to IP addresses when communication with
 the named host is required.  This raises a temporal aspect to
 defining MIB objects whose value is a DNS name: When is the name
 translated to an address?
 For example, consider an object defined to indicate a forwarding
 destination, and whose value is a DNS name.  When does the forwarding
 entity resolve the DNS name?  Each time forwarding occurs or just
 once when the object was instantiated?
 The DESCRIPTION clause of such objects SHOULD precisely define how
 and when any required name to address resolution is done.
 Similarly, the DESCRIPTION clause of such objects SHOULD precisely
 define how and when a reverse lookup is being done if an agent has
 accessed instrumentation that knows about an IP address and the MIB
 module or implementation requires it to map the IP address to a DNS
 name.

5. Table Indexing Example

 This example shows a table listing communication peers that are
 identified by either an IPv4 address, an IPv6 address or a DNS name.
 The table definition also prohibits entries with an empty address
 (whose type would be "unknown").  The size of a DNS name is limited
 to 64 characters in order to satisfy OID length constraints.

Daniele, et. al. Standards Track [Page 13] RFC 3291 TCs for Internet Network Addresses May 2002

 peerTable OBJECT-TYPE
     SYNTAX      SEQUENCE OF PeerEntry
     MAX-ACCESS  not-accessible
     STATUS      current
     DESCRIPTION
         "A list of communication peers."
     ::= { somewhere 1 }
 peerEntry OBJECT-TYPE
     SYNTAX      PeerEntry
     MAX-ACCESS  not-accessible
     STATUS      current
     DESCRIPTION
         "An entry containing information about a particular peer."
     INDEX       { peerAddressType, peerAddress }
     ::= { peerTable 1 }
 PeerEntry ::= SEQUENCE {
     peerAddressType     InetAddressType,
     peerAddress         InetAddress,
     peerStatus          INTEGER
 }
 peerAddressType OBJECT-TYPE
     SYNTAX      InetAddressType
     MAX-ACCESS  not-accessible
     STATUS      current
     DESCRIPTION
         "The type of Internet address by which the peer
          is reachable."
     ::= { peerEntry 1 }
 peerAddress OBJECT-TYPE
     SYNTAX      InetAddress (SIZE (1..64))
     MAX-ACCESS  not-accessible
     STATUS      current
     DESCRIPTION
         "The Internet address for the peer. The type of this
          address is determined by the value of the peerAddressType
          object. Note that implementations must limit themselves
          to a single entry in this table per reachable peer.
          The peerAddress may not be empty due to the SIZE
          restriction.

Daniele, et. al. Standards Track [Page 14] RFC 3291 TCs for Internet Network Addresses May 2002

          If a row is created administratively by an SNMP
          operation and the address type value is dns(16), then
          the agent stores the DNS name internally. A DNS name
          lookup must be performed on the internally stored DNS
          name whenever it is being used to contact the peer.
          If a row is created by the managed entity itself and
          the address type value is dns(16), then the agent
          stores the IP address internally. A DNS reverse lookup
          must be performed on the internally stored IP address
          whenever the value is retrieved via SNMP."
     ::= { peerEntry 2 }
 The following compliance statement specifies that compliant
 implementations need only support IPv4/IPv6 addresses without a zone
 indices.  Support for DNS names or IPv4/IPv6 addresses with zone
 indices is not required.
 peerCompliance MODULE-COMPLIANCE
     STATUS      current
     DESCRIPTION
         "The compliance statement of the peer MIB."
     MODULE      -- this module
     MANDATORY-GROUPS    { peerGroup }
     OBJECT  peerAddressType
     SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
     DESCRIPTION
         "An implementation is only required to support IPv4
          and IPv6 addresses without zone indices."
     ::= { somewhere 2 }
 Note that the SMIv2 does not permit inclusion of not-accessible
 objects in an object group (see section 3.1 in STD 58, RFC 2580 [8]).
 It is therefore not possible to formally refine the syntax of
 auxiliary objects which are not-accessible.  In such a case, it is
 suggested to express the refinement informally in the DESCRIPTION
 clause of the MODULE-COMPLIANCE macro invocation.

Daniele, et. al. Standards Track [Page 15] RFC 3291 TCs for Internet Network Addresses May 2002

6. Security Considerations

 This module does not define any management objects.  Instead, it
 defines a set of textual conventions which may be used by other MIB
 modules to define management objects.
 Meaningful security considerations can only be written in the MIB
 modules that define management objects.  This document has therefore
 no impact on the security of the Internet.

7. Acknowledgments

 This document was produced by the Operations and Management Area
 "IPv6MIB" design team.  The authors would like to thank Fred Baker,
 Randy Bush, Richard Draves, Mark Ellison, Bill Fenner, Jun-ichiro
 Hagino, Mike Heard, Tim Jenkins, Glenn Mansfield, Keith McCloghrie,
 Thomas Narten, Erik Nordmark, Peder Chr. Norgaard, Randy Presuhn,
 Andrew Smith, Dave Thaler, Kenneth White, Bert Wijnen, and Brian Zill
 for their comments and suggestions.

8. Intellectual Property Notice

 The IETF takes no position regarding the validity or scope of any
 intellectual property or other rights that might be claimed to
 pertain to the implementation or use of the technology described in
 this document or the extent to which any license under such rights
 might or might not be available; neither does it represent that it
 has made any effort to identify any such rights.  Information on the
 IETF's procedures with respect to rights in standards-track and
 standards-related documentation can be found in BCP 11.  Copies of
 claims of rights made available for publication and any assurances of
 licenses to be made available, or the result of an attempt made to
 obtain a general license or permission for the use of such
 proprietary rights by implementors or users of this specification can
 be obtained from the IETF Secretariat.
 The IETF invites any interested party to bring to its attention any
 copyrights, patents or patent applications, or other proprietary
 rights which may cover technology that may be required to practice
 this standard.  Please address the information to the IETF Executive
 Director.

9. Changes from RFC 2851

 The following changes have been made relative to RFC 2851:
 o  Added new textual conventions InetAddressPrefixLength,
    InetPortNumber, and InetAutonomousSystemNumber.

Daniele, et. al. Standards Track [Page 16] RFC 3291 TCs for Internet Network Addresses May 2002

 o  Rewrote the introduction to say clearly that in general, one
    should define MIB tables that work with all versions of IP.  The
    other approach of multiple tables for different IP versions is
    strongly discouraged.
 o  Added text to the InetAddressType and InetAddress descriptions
    which requires that implementations must reject set operations
    with an inconsistentValue error if they lead to inconsistencies.
 o  Removed the strict ordering constraints.  Description clauses now
    must explain which InetAddressType object provides the context for
    an InetAddress or InetAddressPrefixLength object.
 o  Aligned wordings with the IPv6 scoping architecture document.
 o  Split the InetAddressIPv6 textual convention into the two textual
    conventions (InetAddressIPv6 and InetAddressIPv6z) and introduced
    a new textual convention InetAddressIPv4z.  Added ipv4z(3) and
    ipv6z(4) named numbers to the InetAddressType enumeration.
    Motivations for this change: (i) enable the introduction of a
    textual conventions for non-global IPv4 addresses, (ii) alignment
    with the textual conventions for transport addresses, (iii)
    simpler compliance statements in cases where support for IPv6
    addresses with zone indices is not required, (iv) simplify
    implementations for host systems which will never have to report
    zone indices.

References

 [1]  Bradner, S., "Key words for use in RFCs to Indicate Requirement
      Levels", BCP 14, RFC 2119, March 1997.
 [2]  Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for
      Describing SNMP Management Frameworks", RFC 2571, April 1999.
 [3]  Rose, M. and K. McCloghrie, "Structure and Identification of
      Management Information for TCP/IP-based Internets", STD 16, RFC
      1155, May 1990.
 [4]  Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16,
      RFC 1212, March 1991.
 [5]  Rose, M., "A Convention for Defining Traps for use with the
      SNMP", RFC 1215, March 1991.
 [6]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose,
      M. and S. Waldbusser, "Structure of Management Information
      Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.

Daniele, et. al. Standards Track [Page 17] RFC 3291 TCs for Internet Network Addresses May 2002

 [7]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose,
      M. and S. Waldbusser, "Textual Conventions for SMIv2", STD 58,
      RFC 2579, April 1999.
 [8]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose,
      M. and S. Waldbusser, "Conformance Statements for SMIv2", STD
      58, RFC 2580, April 1999.
 [9]  Case, J., Fedor, M., Schoffstall, M. and J. Davin, "A Simple
      Network Management Protocol (SNMP)", STD 15, RFC 1157, May 1990.
 [10] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
      "Introduction to Community-based SNMPv2", RFC 1901, January
      1996.
 [11] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Transport
      Mappings for Version 2 of the Simple Network Management Protocol
      (SNMPv2)", RFC 1906, January 1996.
 [12] Case, J., Harrington, D., Presuhn, R. and B. Wijnen, "Message
      Processing and Dispatching for the Simple Network Management
      Protocol (SNMP)", RFC 2572, April 1999.
 [13] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM)
      for version 3 of the Simple Network Management Protocol
      (SNMPv3)", RFC 2574, April 1999.
 [14] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Protocol
      Operations for Version 2 of the Simple Network Management
      Protocol (SNMPv2)", RFC 1905, January 1996.
 [15] Levi, D., Meyer, P. and B. Stewart, "SNMP Applications", RFC
      2573, April 1999.
 [16] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access
      Control Model (VACM) for the Simple Network Management Protocol
      (SNMP)", RFC 2575, April 1999.
 [17] Case, J., Mundy, R., Partain, D. and B. Stewart, "Introduction
      to Version 3 of the Internet-standard Network Management
      Framework", RFC 2570, April 1999.
 [18] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB",
      RFC 2863, June 2000.
 [19] Hinden, R. and S. Deering, "IP Version 6 Addressing
      Architecture", RFC 2373, July 1998.

Daniele, et. al. Standards Track [Page 18] RFC 3291 TCs for Internet Network Addresses May 2002

 [20] Gilligan, R., Thomson, S., Bound, J. and W. Stevens, "Basic
      Socket Interface Extensions for IPv6", RFC 2553, March 1999.
 [21] Deering, S., Haberman, B., Jinmei, T., Nordmark, E., Onoe, A.
      and B. Zill, "IPv6 Scoped Address Architecture", Work in
      Progress.

Authors' Addresses

 Mike Daniele
 Consultant
 19 Pinewood Rd
 Hudson, NH  03051
 USA
 Phone: +1 603 883-6365
 EMail: md@world.std.com
 Brian Haberman
 Phone: +1 919 949-4828
 EMail: bkhabs@nc.rr.com
 Shawn A. Routhier
 Wind River Systems, Inc.
 500 Wind River Way
 Alameda, CA 94501
 USA
 Phone: +1 510 749 2095
 EMail: sar@epilogue.com
 Juergen Schoenwaelder
 TU Braunschweig
 Bueltenweg 74/75
 38106 Braunschweig
 Germany
 Phone: +49 531 391-3289
 EMail: schoenw@ibr.cs.tu-bs.de

Daniele, et. al. Standards Track [Page 19] RFC 3291 TCs for Internet Network Addresses May 2002

Full Copyright Statement

 Copyright (C) The Internet Society (2002).  All Rights Reserved.
 This document and translations of it may be copied and furnished to
 others, and derivative works that comment on or otherwise explain it
 or assist in its implementation may be prepared, copied, published
 and distributed, in whole or in part, without restriction of any
 kind, provided that the above copyright notice and this paragraph are
 included on all such copies and derivative works.  However, this
 document itself may not be modified in any way, such as by removing
 the copyright notice or references to the Internet Society or other
 Internet organizations, except as needed for the purpose of
 developing Internet standards in which case the procedures for
 copyrights defined in the Internet Standards process must be
 followed, or as required to translate it into languages other than
 English.
 The limited permissions granted above are perpetual and will not be
 revoked by the Internet Society or its successors or assigns.
 This document and the information contained herein is provided on an
 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

 Funding for the RFC Editor function is currently provided by the
 Internet Society.

Daniele, et. al. Standards Track [Page 20]

/data/webs/external/dokuwiki/data/pages/rfc/rfc3291.txt · Last modified: 2002/05/13 18:41 (external edit)