rfc1650.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

Network Working Group                                      F. Kastenholz
Request for Comments: 1650                            FTP Software, Inc.
Category: Standards Track                                    August 1994


                  Definitions of Managed Objects for
             the Ethernet-like Interface Types using SMIv2

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.

Table of Contents

   1. Introduction ..........................................    1
   2. The SNMPv2 Network Management Framework ...............    2
   2.1 Object Definitions ...................................    2
   3. Change Log ............................................    2
   4. Overview ..............................................    3
   4.1 Relation to RFC 1213 .................................    4
   4.2 Relation to RFC 1573 .................................    4
   4.2.1 Layering Model .....................................    4
   4.2.2 Virtual Circuits ...................................    4
   4.2.3 ifTestTable ........................................    4
   4.2.4 ifRcvAddressTable ..................................    5
   4.2.5 ifPhysAddress ......................................    5
   4.2.6 ifType .............................................    6
   5. Definitions ...........................................    6
   6. Acknowledgements ......................................   18
   7. References ............................................   19
   8. Security Considerations ...............................   20
   9. Author's Address ......................................   20

1.  Introduction

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it defines objects for managing ethernet-like objects.

   This memo also includes a MIB module.  This MIB module corrects minor
   errors in the earlier version of this MIB: RFC 1398 [15] and also
   re-specifies that MIB in a manner which is both compliant to the
   SNMPv2 SMI and semantically-identical to the existing SNMPv1-based
   definitions.



Kastenholz                                                      [Page 1]

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2.  The SNMPv2 Network Management Framework

   The SNMPv2 Network Management Framework consists of four major
   components.  They are:

      o    RFC 1442 [16] which defines the SMI, the mechanisms used
           for describing and naming objects for the purpose of
           management.

      o    STD 17, RFC 1213 [6] defines MIB-II, the core set of
           managed objects for the Internet suite of protocols.

      o    RFC 1445 [17] which defines the administrative and other
           architectural aspects of the framework.

      o    RFC 1448 [18] which defines the protocol used for network
           access to managed objects.

   The Framework permits new objects to be defined for the purpose of
   experimentation and evaluation.

2.1.  Object Definitions

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the subset of Abstract Syntax Notation One (ASN.1) [7]
   defined in the SMI [16].  In particular, each object object type is
   named by an OBJECT IDENTIFIER, an administratively assigned name.
   The object type together with an object instance serves to uniquely
   identify a specific instantiation of the object.  For human
   convenience, we often use a textual string, termed the descriptor, to
   refer to the object type.

3.  Change Log

   This section enumerates changes made to RFC 1398 to produce this
   document.

      (1)   The "boilerplate" was changed to reflect the new
            boilerplate for SNMPv2.

      (2)   A section describing the applicability of various parts
            of RFC 1573 to ethernet-like interfaces has been added.

      (3)   A minor error in the description of the TDR test was
            fixed.





Kastenholz                                                      [Page 2]

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      (4)   A loopback test was defined to replace the standard
            loopback test that was defined in RFC 1229.

      (5)   The description of dot3CollFrequencies was made a bit
            clearer.

      (6)   A new object, EtherChipset, has been added. This object
            replaces the ifExtnsChipSet object, which has been
            removed per the Interface MIB Evolution effort.

      (7)   Several minor editorial changes, spelling corrections,
            grammar and punctuation corrections, and so forth, were
            made.

4.  Overview

   Instances of these object types represent attributes of an interface
   to an ethernet-like communications medium.  At present, ethernet-like
   media are identified by three values of the ifType object in the
   Internet-standard MIB:

         ethernet-csmacd(6)
         iso88023-csmacd(7)
         starLan(11)

   For these interfaces, the value of the ifSpecific variable in the
   MIB-II [6] has the OBJECT IDENTIFIER value:

      dot3    OBJECT IDENTIFER ::= { transmission 7 }

   The definitions presented here are based on the IEEE 802.3 Layer
   Management Specification [9], as originally interpreted by Frank
   Kastenholz then of Interlan in [10].  Implementors of these MIB
   objects should note that the IEEE document explicitly describes (in
   the form of Pascal pseudocode) when, where, and how various MAC
   attributes are measured.  The IEEE document also describes the
   effects of MAC actions that may be invoked by manipulating instances
   of the MIB objects defined here.

   To the extent that some of the attributes defined in [9] are
   represented by previously defined objects in the Internet-standard
   MIB or in the Generic Interface Extensions MIB [11], such attributes
   are not redundantly represented by objects defined in this memo.
   Among the attributes represented by objects defined in other memos
   are the number of octets transmitted or received on a particular
   interface, the number of frames transmitted or received on a
   particular interface, the promiscuous status of an interface, the MAC
   address of an interface, and multicast information associated with an



Kastenholz                                                      [Page 3]

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   interface.

4.1.  Relation to RFC 1213

   This section applies only when this MIB is used in conjunction with
   the "old" (i.e., pre-RFC 1573) interface group.

   The relationship between an ethernet-like interface and an interface
   in the context of the Internet-standard MIB is one-to-one.  As such,
   the value of an ifIndex object instance can be directly used to
   identify corresponding instances of the objects defined herein.

4.2.  Relation to RFC 1573

   RFC 1573, the Interface MIB Evolution, requires that any MIB which is
   an adjunct of the Interface MIB, clarify specific areas within the
   Interface MIB.  These areas were intentionally left vague in RFC 1573
   to avoid over constraining the MIB, thereby precluding management of
   certain media-types.

   Section 3.3 of RFC 1573 enumerates several areas which a media-
   specific MIB must clarify.  Each of these areas is addressed in a
   following subsection.  The implementor is referred to RFC 1573 in
   order to understand the general intent of these areas.

4.2.1.  Layering Model

   This MIB does not provide for layering.  There are no sublayers.

   EDITOR'S NOTE:

      I could forsee the development of an 802.2 and enet-transceiver
      MIB.  They could be higher and lower sublayers, respectively.  All
      that THIS document should do is allude to the possibilities and
      urge the implementor to be aware of the possibility and that they
      may have requirements which supersede the requirements in this
      document.

4.2.2.  Virtual Circuits

      This medium does not support virtual circuits and this area is not
      applicable to this MIB.

4.2.3.  ifTestTable

      This MIB defines two tests for media which are instumented with
      this MIB; TDR and Loopback.  Implementation of these tests is not
      required.  Many common interface chips do not support one or both



Kastenholz                                                      [Page 4]

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      of these tests.

      These two tests are provided as a convenience, allowing a common
      method to invoke the test.

      Standard MIBs do not include objects in which to return the
      results of the TDR test.  Any needed objects MUST be provided in
      the vendor specific MIB.

4.2.4.  ifRcvAddressTable

      This table contains all IEEE 802.3 addresses, unicast, multicast,
      and broadcast, for which this interface will receive packets and
      forward them up to a higher layer entity for local consumption.
      The format of the address, contained in ifRcvAddressAddress, is
      the same as for ifPhysAddress.

      In the event that the interface is part of a MAC bridge, this
      table does not include unicast addresses which are accepted for
      possible forwarding out some other port.  This table is explicitly
      not intended to provide a bridge address filtering mechanism.

4.2.5.  ifPhysAddress

      This object contains the IEEE 802.3 address which is placed in the
      source-address field of any Ethernet, Starlan, or IEEE 802.3
      frames that originate at this interface.  Usually this will be
      kept in ROM on the interface hardware.  Some systems may set this
      address via software.

      In a system where there are several such addresses the designer
      has a tougher choice.  The address chosen should be the one most
      likely to be of use to network management (e.g.  the address
      placed in ARP responses for systems which are primarily IP
      systems).

      If the designer truly can not chose, use of the factory- provided
      ROM address is suggested.

      If the address can not be determined, an octet string of zero
      length should be returned.

      The address is stored in binary in this object.  The address is
      stored in "canonical" bit order, that is, the Group Bit is
      positioned as the low-order bit of the first octet.  Thus, the
      first byte of a multicast address would have the bit 0x01 set.





Kastenholz                                                      [Page 5]

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4.2.6.  ifType

      This MIB applies to interfaces which have any of the following
      three ifType values:

         ethernet-csmacd(6)
         iso88023-csmacd(7)
         starLan(11)

   Interfaces with any of these ifType values map to the EtherLike-MIB
   in the same manner.  The EtherLike-MIB applies equally to all three
   types; there are no implementation differences.

5.  Definitions

EtherLike-MIB DEFINITIONS ::= BEGIN

   IMPORTS
       MODULE-IDENTITY, OBJECT-TYPE, Counter32, Gauge32,
       Integer32,                               FROM SNMPv2-SMI
       TEXTUAL-CONVENTION, PhysAddress,         FROM SNMPv2-TC
       MODULE-COMPLIANCE, OBJECT-GROUP          FROM SNMPv2-CONF
       ifIndex, ifEntry                         FROM IF-MIB
       mib-2                                    FROM RFC1213-MIB;

   etherMIB MODULE-IDENTITY
       LAST-UPDATED "9402030400Z"
       ORGANIZATION "IETF Interfaces MIB Working Group"
       CONTACT-INFO

        "        Frank Kastenholz

         Postal: FTP Software
                 2 High Street
                 North Andover, MA 01845
                 US

            Tel: [phone]
         E-Mail: [e-mail]"
       DESCRIPTION
     "The MIB module to describe generic objects for
     Ethernet-like network interfaces. This MIB is an
     updated version of the Ethernet-like MIB in RFC
     1398."
       ::= { mib-2 35 }

   etherMIBObjects OBJECT IDENTIFIER ::= { etherMIB 1 }




Kastenholz                                                      [Page 6]

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   dot3    OBJECT IDENTIFIER ::= { transmission 7 }

   -- the Ethernet-like Statistics group

    dot3StatsTable  OBJECT-TYPE
         SYNTAX     SEQUENCE OF Dot3StatsEntry
         MAX-ACCESS not-accessible
         STATUS     current
         DESCRIPTION
          "Statistics for a collection of ethernet-like
          interfaces attached to a particular system."
         ::= { dot3 2 }


    dot3StatsEntry   OBJECT-TYPE
         SYNTAX      Dot3StatsEntry
         MAX-ACCESS  not-accessible
         STATUS      current
         DESCRIPTION
           "Statistics for a particular interface to an
           ethernet-like medium."
         INDEX       { dot3StatsIndex }
         ::= { dot3StatsTable 1 }

    Dot3StatsEntry ::= SEQUENCE {
         dot3StatsIndex                      INTEGER,
         dot3StatsAlignmentErrors            Counter32,
         dot3StatsFCSErrors                  Counter32,
         dot3StatsSingleCollisionFrames      Counter32,
         dot3StatsMultipleCollisionFrames    Counter32,
         dot3StatsSQETestErrors              Counter32,
         dot3StatsDeferredTransmissions      Counter32,
         dot3StatsLateCollisions             Counter32,