Internet Draft
INTERNET-DRAFT                                   Editor of this version:
Request for Comments: -TM                                     R. Presuhn
STD: XXX                                              BMC Software, Inc.
Obsoletes: 1906                             Authors of previous version:
Category: Standards Track                                        J. Case
                                                     SNMP Research, Inc.
                                                           K. McCloghrie
                                                     Cisco Systems, Inc.
                                                                 M. Rose
                                            Dover Beach Consulting, Inc.
                                                           S. Waldbusser
                                          International Network Services
                                                            14 July 2000

                         Transport Mappings for
                 the Simple Network Management Protocol
               <draft-ietf-snmpv3-update-transmap-04.txt>

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.  Internet-Drafts are working
   documents of the Internet Engineering Task Force (IETF), its areas,
   and its working groups.  Note that other groups may also distribute
   working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html

Copyright Notice

   Copyright (C) The Internet Society (2000).  All Rights Reserved.

Abstract

   This document defines the transport of SNMP messages over various
   protocols.  This document obsoletes RFC 1906.






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Table of Contents

   1. Introduction ................................................    3
   2. Definitions .................................................    4
   3. SNMP over UDP over IPv4 .....................................    7
   3.1. Serialization .............................................    7
   3.2. Well-known Values .........................................    8
   4. SNMP over OSI ...............................................    8
   4.1. Serialization .............................................    8
   4.2. Well-known Values .........................................    8
   5. SNMP over DDP ...............................................    8
   5.1. Serialization .............................................    8
   5.2. Well-known Values .........................................    9
   5.3. Discussion of AppleTalk Addressing ........................    9
   5.3.1. How to Acquire NBP names ................................   10
   5.3.2. When to Turn NBP names into DDP addresses ...............   10
   5.3.3. How to Turn NBP names into DDP addresses ................   11
   5.3.4. What if NBP is broken ...................................   11
   6. SNMP over IPX ...............................................   12
   6.1. Serialization .............................................   12
   6.2. Well-known Values .........................................   12
   7. Proxy to SNMPv1 .............................................   12
   8. Serialization using the Basic Encoding Rules ................   12
   8.1. Usage Example .............................................   13
   9. Notice on Intellectual Property .............................   14
   10. Acknowledgments ............................................   14
   11. Security Considerations ....................................   16
   12. References .................................................   16
   13. Editor's Address ...........................................   18
   14. Changes from RFC 1906 ......................................   19
   15. Issues .....................................................   20
   16. Full Copyright Statement ...................................   21



















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1.  Introduction

   The SNMP Management Framework at the time of this writing consists of
   five major components:

        -    An overall architecture, described in RFC 2571 [RFC2571].

        -    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 [RFC1155], STD 16, RFC
             1212 [RFC1212] and RFC 1215 [RFC1215].  The second version,
             called SMIv2, is described in STD 58, RFC 2578 [RFC2578],
             STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580 [RFC2580].

        -    Message protocols for transferring management information.
             The first version of the SNMP message protocol is called
             SNMPv1 and is described in STD 15, RFC 1157 [RFC1157].  A
             second version of the SNMP message protocol, which is not
             an Internet standards track protocol, is called SNMPv2c and
             is described in RFC 1901 [RFC1901] and this document.  The
             third version of the message protocol is called SNMPv3 and
             described in this document, RFC 2572 [RFC2572] and RFC 2574
             [RFC2574].

        -    Protocol operations for accessing management information.
             The first set of protocol operations and associated PDU
             formats is described in STD 15, RFC 1157 [RFC1157].  A
             second set of protocol operations and associated PDU
             formats is described RFC -PROTO [RFC-PROTO].

        -    A set of fundamental applications described in RFC 2573
             [RFC2573] and the view-based access control mechanism
             described in RFC 2575 [RFC2575].

   A more detailed introduction to the SNMP Management Framework at the
   time of this writing can be found in RFC 2570 [RFC2570].

   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 document, Transport Mappings for the Simple Network Management
   Protocol, defines how the management protocol [RFC-PROTO] may be
   carried over a variety of protocol suites.  It is the purpose of this
   document to define how the SNMP maps onto an initial set of transport
   domains.  Other mappings may be defined in the future.




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   Although several mappings are defined, the mapping onto UDP over IPv4
   is the preferred mapping.  As such, to provide for the greatest level
   of interoperability, systems which choose to deploy other mappings
   should also provide for access via UDP over IPv4 mapping.

2.  Definitions

   SNMPv2-TM DEFINITIONS ::= BEGIN

   IMPORTS
       MODULE-IDENTITY, OBJECT-IDENTITY,
       snmpModules, snmpDomains, snmpProxys
           FROM SNMPv2-SMI
       TEXTUAL-CONVENTION
           FROM SNMPv2-TC;

   snmpv2tm MODULE-IDENTITY
       LAST-UPDATED "200007141725Z"
       ORGANIZATION "IETF SNMPv3 Working Group"
       CONTACT-INFO
               "WG-EMail:   snmpv3@tis.com
                Subscribe:  majordomo@tis.com
                            In message body:  subscribe snmpv3

                Chair:      Russ Mundy
                            TIS Labs at Network Associates
                postal:     3060 Washington Rd
                            Glenwood MD 21738
                            USA
                EMail:      mundy@tislabs.com
                phone:      +1 301 854-6889

                Editor:     Randy Presuhn
                            BMC Software, Inc.
                postal:     2141 North First Street
                            San Jose, CA 95131
                            USA
                EMail:      randy_presuhn@bmc.com
                phone:      +1 408 546-1006"
       DESCRIPTION
               "The MIB module for SNMP transport mappings."
       REVISION     "200007141725Z"
       DESCRIPTION
               "Clarifications, published as
                <draft-ietf-snmpv3-update-transmap-04.txt>"
       REVISION    "199601010000Z"
       DESCRIPTION
               "Clarifications, published as RFC 1906."



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       REVISION    "199304010000Z"
       DESCRIPTION
               "The initial version, published as RFC 1449."
       ::= { snmpModules ?? }  -- to be assigned by IANA??

   -- SNMP over UDP over IPv4

   snmpUDPDomain  OBJECT-IDENTITY
       STATUS     current
       DESCRIPTION
               "The SNMP over UDP over IPv4 transport domain.
               The corresponding transport address is of type
               SnmpUDPAddress."
       ::= { snmpDomains 1 }

   SnmpUDPAddress ::= TEXTUAL-CONVENTION
       DISPLAY-HINT "1d.1d.1d.1d/2d"
       STATUS       current
       DESCRIPTION
               "Represents a UDP over IPv4 address:

                  octets   contents        encoding
                   1-4     IP-address      network-byte order
                   5-6     UDP-port        network-byte order
               "
       SYNTAX       OCTET STRING (SIZE (6))


   -- SNMP over OSI

   snmpCLNSDomain OBJECT-IDENTITY
       STATUS     current
       DESCRIPTION
               "The SNMP over CLNS transport domain.
               The corresponding transport address is of type
               SnmpOSIAddress."
       ::= { snmpDomains 2 }

   snmpCONSDomain OBJECT-IDENTITY
       STATUS     current
       DESCRIPTION
               "The SNMP over CONS transport domain.
               The corresponding transport address is of type
               SnmpOSIAddress."
       ::= { snmpDomains 3 }






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   SnmpOSIAddress ::= TEXTUAL-CONVENTION
       DISPLAY-HINT "*1x:/1x:"
       STATUS       current
       DESCRIPTION
               "Represents an OSI transport-address:

             octets   contents           encoding
                1     length of NSAP     'n' as an unsigned-integer
                                            (either 0 or from 3 to 20)
             2..(n+1) NSAP                concrete binary representation
             (n+2)..m TSEL                string of (up to 64) octets
               "
       SYNTAX       OCTET STRING (SIZE (1 | 4..85))


   -- SNMP over DDP

   snmpDDPDomain  OBJECT-IDENTITY
       STATUS     current
       DESCRIPTION
               "The SNMP over DDP transport domain.  The corresponding
               transport address is of type SnmpNBPAddress."
       ::= { snmpDomains 4 }

   SnmpNBPAddress ::= TEXTUAL-CONVENTION
       STATUS       current
       DESCRIPTION
               "Represents an NBP name:

            octets        contents          encoding
               1          length of object  'n' as an unsigned integer
             2..(n+1)     object            string of (up to 32) octets
              n+2         length of type    'p' as an unsigned integer
         (n+3)..(n+2+p)   type              string of (up to 32) octets
             n+3+p        length of zone    'q' as an unsigned integer
       (n+4+p)..(n+3+p+q) zone              string of (up to 32) octets

               For comparison purposes, strings are
               case-insensitive. All strings may contain any octet
               other than 255 (hex ff)."
       SYNTAX       OCTET STRING (SIZE (3..99))










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   -- SNMP over IPX

   snmpIPXDomain  OBJECT-IDENTITY
       STATUS     current
       DESCRIPTION
               "The SNMP over IPX transport domain.  The corresponding
               transport address is of type SnmpIPXAddress."
       ::= { snmpDomains 5 }

   SnmpIPXAddress ::= TEXTUAL-CONVENTION
       DISPLAY-HINT "4x.1x:1x:1x:1x:1x:1x.2d"
       STATUS       current
       DESCRIPTION
               "Represents an IPX address:

                  octets   contents            encoding
                   1-4     network-number      network-byte order
                   5-10    physical-address    network-byte order
                  11-12    socket-number       network-byte order
               "
       SYNTAX       OCTET STRING (SIZE (12))


   -- for proxy to SNMPv1 (RFC 1157)

   rfc1157Proxy   OBJECT IDENTIFIER ::= { snmpProxys 1 }

   rfc1157Domain  OBJECT-IDENTITY
       STATUS     deprecated
       DESCRIPTION
               "The transport domain for SNMPv1 over UDP over IPv4.
               The corresponding transport address is of type
               SnmpUDPAddress."
       ::= { rfc1157Proxy 1 }

   --  ::= { rfc1157Proxy 2 }            this OID is obsolete

   END

3.  SNMP over UDP over IPv4

   This is the preferred transport mapping.

3.1.  Serialization

   Each instance of a message is serialized (i.e., encoded according to
   the convention of [ASN1]) onto a single UDP [RFC768] over IPv4
   [RFC791] datagram, using the algorithm specified in Section 8.



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3.2.  Well-known Values

   It is suggested that administrators configure their SNMP entities
   supporting command responder applications to listen on UDP port 161.
   Further, it is suggested that SNMP entities supporting notification
   receiver applications be configured to listen on UDP port 162.

   When an SNMP entity uses this transport mapping, it must be capable
   of accepting messages up to and including 484 octets in size.  It is
   recommended that implementations be capable of accepting messages of
   up to 1472 octets in size.  Implementation of larger values is
   encouraged whenever possible.

4.  SNMP over OSI

   This is an optional transport mapping.

4.1.  Serialization

   Each instance of a message is serialized onto a single TSDU [IS8072]
   [IS8072A] for the OSI Connectionless-mode Transport Service (CLTS),
   using the algorithm specified in Section 8.

4.2.  Well-known Values

   It is suggested that administrators configure their SNMP entities
   supporting command responder applications to listen on transport
   selector "snmp-l" (which consists of six ASCII characters), when
   using a CL-mode network service to realize the CLTS.  Further, it is
   suggested that SNMP entities supporting notification receiver
   applications be configured to listen on transport selector "snmpt-l"
   (which consists of seven ASCII characters, six letters and a hyphen)
   when using a CL-mode network service to realize the CLTS.  Similarly,
   when using a CO-mode network service to realize the CLTS, the
   suggested transport selectors are "snmp-o" and "snmpt-o", for command
   responders and notification receivers, respectively.

   When an SNMP entity uses this transport mapping, it must be capable
   of accepting messages that are at least 484 octets in size.
   Implementation of larger values is encouraged whenever possible.

5.  SNMP over DDP

   This is an optional transport mapping.







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5.1.  Serialization

   Each instance of a message is serialized onto a single  DDP  datagram
   [APPLETALK], using the algorithm specified in Section 8.

5.2.  Well-known Values

   SNMP messages are sent using DDP protocol type 8.  SNMP entities
   supporting command responder applications listen on DDP socket number
   8, while SNMP entities supporting notification receiver applications
   listen on DDP socket number 9.

   Administrators must configure their SNMP entities supporting command
   responder applications to use NBP type "SNMP Agent" (which consists
   of ten ASCII while those supporting notification receiver
   applications must be configured to use NBP type "SNMP Trap Handler"
   (which consists of seventeen ASCII characters).

   The NBP name for SNMP entities supporting command responders and
   notification receivers should be stable - NBP names should not change
   any more often than the IP address of a typical TCP/IP node.  It is
   suggested that the NBP name be stored in some form of stable storage.

   When an SNMP entity uses this transport mapping, it must be capable
   of accepting messages that are at least 484 octets in size.
   Implementation of larger values is encouraged whenever possible.

5.3.  Discussion of AppleTalk Addressing

   The AppleTalk protocol suite has certain features not manifest in the
   TCP/IP suite.  AppleTalk's naming strategy and the dynamic nature of
   address assignment can cause problems for SNMP entities that wish to
   manage AppleTalk networks.  TCP/IP nodes have an associated IP
   address which distinguishes each from the other.  In contrast,
   AppleTalk nodes generally have no such characteristic.  The network-
   level address, while often relatively stable, can change at every
   reboot (or more frequently).

   Thus, when SNMP is mapped over DDP, nodes are identified by a "name",
   rather than by an "address".  Hence, all AppleTalk nodes that
   implement this mapping are required to respond to NBP lookups and
   confirms (e.g., implement the NBP protocol stub), which guarantees
   that a mapping from NBP name to DDP address will be possible.

   In determining the SNMP identity to register for an SNMP entity, it
   is suggested that the SNMP identity be a name which is associated
   with other network services offered by the machine.



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   NBP lookups, which are used to map NBP names into DDP addresses, can
   cause large amounts of network traffic as well as consume CPU
   resources.  It is also the case that the ability to perform an NBP
   lookup is sensitive to certain network disruptions (such as zone
   table inconsistencies) which would not prevent direct AppleTalk
   communications between two SNMP entities.

   Thus, it is recommended that NBP lookups be used infrequently,
   primarily to create a cache of name-to-address mappings.  These
   cached mappings should then be used for any further SNMP traffic.  It
   is recommended that SNMP entities supporting command generator
   applications should maintain this cache between reboots.  This
   caching can help minimize network traffic, reduce CPU load on the
   network, and allow for (some amount of) network trouble shooting when
   the basic name-to-address translation mechanism is broken.

5.3.1.  How to Acquire NBP names

   An SNMP entity supporting command generator applications may have a
   pre-configured list of names of "known" SNMP entities supporting
   command responder applications.  Similarly, an SNMP entity supporting
   command generator or notification receiver applications might
   interact with an operator.  Finally, an SNMP entity supporting
   command generator or notification receiver applications might
   communicate with all SNMP entities supporting command responder or
   notification originator applications in a set of zones or networks.

5.3.2.  When to Turn NBP names into DDP addresses

   When an SNMP entity uses a cache entry to address an SNMP packet, it
   should attempt to confirm the validity mapping, if the mapping hasn't
   been confirmed within the last T1 seconds.  This cache entry
   lifetime, T1, has a minimum, default value of 60 seconds, and should
   be configurable.

   An SNMP entity supporting a command generator application may decide
   to prime its cache of names prior to actually communicating with
   another SNMP entity.  In general, it is expected that such an entity
   may want to keep certain mappings "more current" than other mappings,
   e.g., those nodes which represent the network infrastructure (e.g.,
   routers) may be deemed "more important".

   Note that an SNMP entity supporting command generator applications
   should not prime its entire cache upon initialization - rather, it
   should attempt resolutions over an extended period of time (perhaps
   in some pre- determined or configured priority order).  Each of these
   resolutions might, in fact, be a wildcard lookup in a given zone.




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   An SNMP entity supporting command responder applications must never
   prime its cache.  When generating a response, such an entity does not
   need to confirm a cache entry.  An SNMP entity supporting
   notification originator applications should do NBP lookups (or
   confirms) only when it needs to send an SNMP trap or inform.

5.3.3.  How to Turn NBP names into DDP addresses

   If the only piece of information available is the NBP name, then an
   NBP lookup should be performed to turn that name into a DDP address.
   However, if there is a piece of stale information, it can be used as
   a hint to perform an NBP confirm (which sends a unicast to the
   network address which is presumed to be the target of the name
   lookup) to see if the stale information is, in fact, still valid.

   An NBP name to DDP address mapping can also be confirmed implicitly
   using only SNMP transactions.  For example, an SNMP entity supporting
   command generator applications issuing a retrieval operation could
   also retrieve the relevant objects from the NBP group [RFC1742] for
   the SNMP entity supporting the command responder application.  This
   information can then be correlated with the source DDP address of the
   response.

5.3.4.  What if NBP is broken

   Under some circumstances, there may be connectivity between two SNMP
   entities, but the NBP mapping machinery may be broken, e.g.,

   o    the NBP FwdReq (forward NBP lookup onto local attached network)
        mechanism might be broken at a router on the other entity's
        network; or,

   o    the NBP BrRq (NBP broadcast request) mechanism might be broken
        at a router on the entity's own network; or,

   o    NBP might be broken on the other entity's node.

   An SNMP entity supporting command generator applications which is
   dedicated to AppleTalk management might choose to alleviate some of
   these failures by directly implementing the router portion of NBP.
   For example, such an entity might already know all the zones on the
   AppleTalk internet and the networks on which each zone appears.
   Given an NBP lookup which fails, the entity could send an NBP FwdReq
   to the network in which the SNMP entity supporting the command
   responder or notification originator application was last located.
   If that failed, the station could then send an NBP LkUp (NBP lookup
   packet) as a directed (DDP) multicast to each network number on that
   network.  Of the above (single) failures, this combined approach will



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   solve the case where either the local router's BrRq-to-FwdReq
   mechanism is broken or the remote router's FwdReq-to-LkUp mechanism
   is broken.

6.  SNMP over IPX

   This is an optional transport mapping.

6.1.  Serialization

   Each instance of a message is serialized onto a single IPX datagram
   [NOVELL], using the algorithm specified in Section 8.

6.2.  Well-known Values

   SNMP messages are sent using IPX packet type 4 (i.e., Packet Exchange
   Protocol).

   It is suggested that administrators configure their SNMP entities
   supporting command responder applications to listen on IPX socket
   36879 (900f hexadecimal).  Further, it is suggested that those
   supporting notification receiver applications be configured to listen
   on IPX socket 36880 (9010 hexadecimal).

   When an SNMP entity uses this transport mapping, it must be capable
   of accepting messages that are at least 546 octets in size.
   Implementation of larger values is encouraged whenever possible.

7.  Proxy to SNMPv1

   Historically, in order to support proxy to SNMPv1, as defined in
   [RFC2576], it was deemed useful to define a transport domain,
   rfc1157Domain, which indicates the transport mapping for SNMP
   messages as defined in [RFC1157].

8.  Serialization using the Basic Encoding Rules

   When the Basic Encoding Rules [BER] are used for serialization:

   (1)  When encoding the length field, only the definite form is used;
        use of the indefinite form encoding is prohibited.  Note that
        when using the definite-long form, it is permissible to use more
        than the minimum number of length octets necessary to encode the
        length field.

   (2)  When encoding the value field, the primitive form shall be used
        for all simple types, i.e., INTEGER, OCTET STRING, and OBJECT
        IDENTIFIER (either IMPLICIT or explicit).  The constructed form



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        of encoding shall be used only for structured types, i.e., a
        SEQUENCE or an IMPLICIT SEQUENCE.

   (3)  When encoding an object whose syntax is described using the BITS
        construct, the value is encoded as an OCTET STRING, in which all
        the named bits in (the definition of) the bitstring, commencing
        with the first bit and proceeding to the last bit, are placed in
        bits 8 (high order bit) to 1 (low order bit) of the first octet,
        followed by bits 8 to 1 of each subsequent octet in turn,
        followed by as many bits as are needed of the final subsequent
        octet, commencing with bit 8.  Remaining bits, if any, of the
        final octet are set to zero on generation and ignored on
        receipt.

   These restrictions apply to all aspects of ASN.1 encoding, including
   the message wrappers, protocol data units, and the data objects they
   contain.

8.1.  Usage Example

   As an example of applying the Basic Encoding Rules, suppose one
   wanted to encode an instance of the GetBulkRequest-PDU [RFC-PROTO]:

     [5] IMPLICIT SEQUENCE {
             request-id      1414684022,
             non-repeaters   1,
             max-repetitions 2,
             variable-bindings {
                 { name sysUpTime,
                   value { unspecified NULL } },
                 { name ipNetToMediaPhysAddress,
                   value { unspecified NULL } },
                 { name ipNetToMediaType,
                   value { unspecified NULL } }
             }
         }















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   Applying the BER, this would be encoded (in hexadecimal) as:

   [5] IMPLICIT SEQUENCE          a5 82 00 39
       INTEGER                    02 04 52 54 5d 76
       INTEGER                    02 01 01
       INTEGER                    02 01 02
       SEQUENCE (OF)              30 2b
           SEQUENCE               30 0b
               OBJECT IDENTIFIER  06 07 2b 06 01 02 01 01 03
               NULL               05 00
           SEQUENCE               30 0d
               OBJECT IDENTIFIER  06 09 2b 06 01 02 01 04 16 01 02
               NULL               05 00
           SEQUENCE               30 0d
               OBJECT IDENTIFIER  06 09 2b 06 01 02 01 04 16 01 04
               NULL               05 00

   Note that the initial SEQUENCE is not encoded using the minimum
   number of length octets.  (The first octet of the length, 82,
   indicates that the length of the content is encoded in the next two
   octets.)

9.  Notice on Intellectual Property

   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.

10.  Acknowledgments

   This document is the product of the SNMPv3 Working Group.  Some



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   special thanks are in order to the following Working Group members:

        Randy Bush
        Jeffrey D. Case
        Mike Daniele
        Rob Frye
        Lauren Heintz
        Keith McCloghrie
        Russ Mundy
        David T. Perkins
        Randy Presuhn
        Aleksey Romanov
        Juergen Schoenwaelder
        Bert Wijnen

   This version of the document, edited by Randy Presuhn, was initially
   based on the work of a design team whose members were:

        Jeffrey D. Case
        Keith McCloghrie
        David T. Perkins
        Randy Presuhn
        Juergen Schoenwaelder

   The  previous versions of this document, edited by Keith McCloghrie,
   was the result of significant work by four major contributors:

        Jeffrey D. Case
        Keith McCloghrie
        Marshall T. Rose
        Steven Waldbusser

   Additionally, the contributions of the SNMPv2 Working Group to the
   previous versions are also acknowledged.  In particular, a special
   thanks is extended for the contributions of:

        Alexander I. Alten
        Dave Arneson
        Uri Blumenthal
        Doug Book
        Kim Curran
        Jim Galvin
        Maria Greene
        Iain Hanson
        Dave Harrington
        Nguyen Hien
        Jeff Johnson
        Michael Kornegay



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        Deirdre Kostick
        David Levi
        Daniel Mahoney
        Bob Natale
        Brian O'Keefe
        Andrew Pearson
        Dave Perkins
        Randy Presuhn
        Aleksey Romanov
        Shawn Routhier
        Jon Saperia
        Juergen Schoenwaelder
        Bob Stewart
        Kaj Tesink
        Glenn Waters
        Bert Wijnen

11.  Security Considerations

   SNMPv1 by itself is not a secure environment.  Even if the network
   itself is secure (for example by using IPSec), even then, there is no
   control as to who on the secure network is allowed to access and
   GET/SET (read/change) the objects accessible through a command
   responder application.

   It is recommended that the implementors consider the security
   features as provided by the SNMPv3 framework.  Specifically, the use
   of the User-based Security Model RFC 2574 [RFC2574] and the
   View-based Access Control Model RFC 2575 [RFC2575] is recommended.

   It is then a customer/user responsibility to ensure that the SNMP
   entity giving access to a MIB is properly configured to give access
   to the objects only to those principals (users) that have legitimate
   rights to indeed GET or SET (change) them.

12.  References

   [APPLETALK] Sidhu, G., Andrews, R., and A. Oppenheimer, Inside
               AppleTalk (second edition).  Addison-Wesley, 1990.

   [BER]       Information processing systems - Open Systems
               Interconnection - Specification of Basic Encoding Rules
               for Abstract Syntax Notation One (ASN.1), International
               Organization for Standardization.  International Standard
               8825, December 1987.






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   [IS8072]    Information processing systems - Open Systems
               Interconnection - Transport Service Definition,
               International Organization for Standardization.
               International Standard 8072, June 1986.

   [IS8072A]   Information processing systems - Open Systems
               Interconnection - Transport Service Definition - Addendum
               1: Connectionless-mode Transmission, International
               Organization for Standardization.  International Standard
               8072/AD 1, December 1986.

   [NOVELL]    Network System Technical Interface Overview.  Novell,
               Inc, June 1989.

   [RFC768]    Postel, J., "User Datagram Protocol", STD 6, RFC 768,
               August 1980.

   [RFC791]    Postel, J., "Internet Protocol", STD 5, RFC 791,
               September 1981.

   [RFC1155]   Rose, M., and K. McCloghrie, "Structure and
               Identification of Management Information for TCP/IP-based
               Internets", STD 16, RFC 1155, May 1990.

   [RFC1157]   Case, J., Fedor, M., Schoffstall, M., and J. Davin,
               "Simple Network Management Protocol", STD 15, RFC 1157,
               May 1990.

   [RFC1212]   Rose, M., and K. McCloghrie, "Concise MIB Definitions",
               STD 16, RFC 1212, March 1991.

   [RFC1215]   Rose, M., "A Convention for Defining Traps for use with
               the SNMP", RFC 1215, March 1991.

   [RFC1742]   Waldbusser, S. and K. Frisa, "AppleTalk Management
               Information Base II", RFC 1742, January 1995.

   [RFC1901]   Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
               "Introduction to Community-based SNMPv2", RFC 1901,
               January 1996.

   [RFC2570]   Case, J., Mundy, R., Partain, D., and B. Stewart,
               "Introduction to Version 3 of the Internet-standard
               Network Management Framework", RFC 2570, April 1999.

   [RFC2571]   Harrington, D., Presuhn, R., and B. Wijnen, "An
               Architecture for Describing SNMP Management Frameworks",
               RFC 2571, April 1999.



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   [RFC2572]   Case, J., Harrington D., Presuhn R., and B. Wijnen,
               "Message Processing and Dispatching for the Simple
               Network Management Protocol (SNMP)", RFC 2572, April
               1999.

   [RFC2573]   Levi, D., Meyer, P., and B. Stewart, "SNMPv3
               Applications", RFC 2573, April 1999.

   [RFC2574]   Blumenthal, U., and B. Wijnen, "User-based Security Model
               (USM) for version 3 of the Simple Network Management
               Protocol (SNMPv3)", RFC 2574, April 1999.

   [RFC2575]   Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based
               Access Control Model (VACM) for the Simple Network
               Management Protocol (SNMP)", RFC 2575, April 1999.

   [RFC2576]   Frye, R., Levi, D., Routhier, S., and B. Wijnen,
               "Coexistence between Version 1, Version 2, and Version 3
               of the Internet-standard Network Management Framework",
               RFC 2576, March, 2000.

   [RFC2578]   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.

   [RFC2579]   McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
               Rose, M., and S. Waldbusser, "Textual Conventions for
               SMIv2", STD 58, RFC 2579, April 1999.

   [RFC2580]   McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
               Rose, M., and S. Waldbusser, "Conformance Statements for
               SMIv2", STD 58, RFC 2580, April 1999.

   [RFC-TM]    Presuhn, R., Case, J., McCloghrie, K., Rose, M., and S.
               Waldbusser, "Transport Mappings for the Simple Network
               Management Protocol",
               <draft-ietf-snmpv3-update-transmap-04.txt>, July 2000.

   [RFC-PROTO] Presuhn, R., Case, J., McCloghrie, K., Rose, M., and S.
               Waldbusser, "Protocol Operations for the Simple Network
               Management Protocol",
               <draft-ietf-snmpv3-update-proto-04.txt>, July 2000.








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13.  Editor's Address

   Randy Presuhn
   BMC Software, Inc.
   2141 North First Street
   San Jose, CA 95131
   USA

   Phone: +1 408 546-1006
   EMail: randy_presuhn@bmc.com

14.  Changes from RFC 1906

   These are the changes from RFC 1906:

        -    Corrected typo in IPR statement;

        -    Updated copyright date;

        -    Updated with new editor's name and contact information;

        -    Cosmetic fixes to layout and typography;

        -    Changed title, headers and footers;

        -    Fixed typo in SnmpNBPAddress;

        -    Clarified that one of the BER SEQUENCEs in the example is
             generated from the ASN.1 SEQUENCE OF construct;

        -    Updated acknowledgements section;

        -    Filled in the Security Considerations section;

        -    Replaced manager/agent terminology with terms from
             architecture;

        -    Updated references section;

        -    Added MODULE-IDENTITY;

        -    Re-wrote introduction section using current boilerplate;

        -    Added recommendation for larger message size support;

        -    Added historical background on use of rfc1157Domain with
             proxy and changed status to "deprecated".



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        -    Added an abstract.

15.  Issues

   This section is to be deleted when it is time to publish this
   document as an RFC.  The issue labels are the same as those used in
   the on-line issues list at
   ftp://amethyst.bmc.com/pub/snmpv3/Update567/rfc1906/index.html

        1906-01 Done; title changed.

        1906-02 Done; introduction clause replaced.

        1906-03

        1906-04 Done; resolution required no changes.

        1906-05 Done; typo in SnmpNBPAddress fixed.

        1906-06 See issue 1906-10.

        1906-07 Done; use of manager/agent terminology replaced with
                terms from architecture.

        1906-08 Done; added recommendation for support of 1472 byte
                messages.

        1906-09 Done; resolution required no changes.

        1906-10 Done; resolved by deprecating the definition.

        1906-11 Done; resolution required no changes.

        1906-12 Done; resolution required no changes.

        1906-13 Done; resolution required no changes.

        1906-14 Done; clarified that BER SEQUENCE comes from ASN.1
                SEQUENCE OF.

        1906-15 Done; security considerations text added.

        1906-16 Done; references and acknowledgments updated.

        1906-17 Done; IPR and copyright notices updated.

        1906-18 Done; resolution required no changes.




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        1906-19 Done; MODULE-IDENTITY added.

        1906-20 Done; resolution was to make no change.

        1906-21 Done; resolution was to make no change.

        1906-22 Done; resolution was to make no change.

        1906-23 Done; added abstract.

16.  Full Copyright Statement

   Copyright (C) The Internet Society (2000).  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.














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