RFC3291

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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.

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.

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.

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].

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].

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.

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: [email protected]
     Send comments to <[email protected]>."
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
     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
     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:
       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
     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))

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)

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

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

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.

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.

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

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].

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.

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.

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.

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.
        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.

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.

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.

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.

Changes from RFC 2851

The following changes have been made relative to RFC 2851:

o Added new textual conventions InetAddressPrefixLength,

  InetPortNumber, and InetAutonomousSystemNumber.

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.

[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.

[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: [email protected]

Brian Haberman

Phone: +1 919 949-4828 EMail: [email protected]

Shawn A. Routhier Wind River Systems, Inc. 500 Wind River Way Alameda, CA 94501 USA

Phone: +1 510 749 2095 EMail: [email protected]

Juergen Schoenwaelder TU Braunschweig Bueltenweg 74/75 38106 Braunschweig Germany

Phone: +49 531 391-3289 EMail: [email protected]

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