[Search] [txt|pdf|bibtex] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01                                                         
Network Working Group                                  Dave Thaler
Internet-Draft                               Microsoft Corporation
Expires: May 2001                               Satyen Chandragiri
                                               Lucent Technologies
                                                     November 2000





                      Subtree Retrieval MIB
             <draft-irtf-nmrg-get-subtree-mib-01.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.






Expires May 2001                                          [Page 1]


Draft                     GET-SUBTREE MIB            November 2000


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 describes managed objects used for
retrieving subtrees of MIB objects without the overshoot problems
of the SNMP GetBulkRequest operation.


2.  The SNMP Network Management Framework

The SNMP Management Framework presently consists of five major
components:

o    An overall architecture, described in RFC 2571 [1].

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 RFC 1155 [2], RFC 1212 [3] and RFC 1215 [4]. The
     second version, called SMIv2, is described in RFC 2578 [5],
     RFC 2579 [6] and RFC 2580 [7].

o    Message protocols for transferring management information.
     The first version of the SNMP message protocol is called
     SNMPv1 and described in RFC 1157 [8]. A second version of the
     SNMP message protocol, which is not an Internet standards
     track protocol, is called SNMPv2c and described in RFC 1901
     [9] and RFC 1906 [10].  The third version of the message
     protocol is called SNMPv3 and described in RFC 1906 [10], RFC
     2572 [11] and RFC 2574 [12].

o    Protocol operations for accessing management information. The
     first set of protocol operations and associated PDU formats
     is described in RFC 1157 [8]. A second set of protocol
     operations and associated PDU formats is described in RFC
     1905 [13].

o    A set of fundamental applications described in RFC 2573 [14]
     and the view-based access control mechanism described in RFC
     2575 [15].

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.





Expires May 2001                                          [Page 2]


Draft                     GET-SUBTREE MIB            November 2000


This memo specifies a MIB module that is compliant with 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.  Overview

A major shortcoming of SNMP is the lack of a mechanism to
efficiently retrieve large amounts of MIB data from a device.
SNMPv1, though widely deployed, contains no provision for bulk
retrieval and the manager must use GetNextRequests to traverse the
MIB. This requires a large number of request-response exchanges
leading to high latency. To address this problem, the
GetBulkRequest operation [13] was introduced in SNMPv2.

The GetBulkRequest operation aims to minimize the number of
protocol exchanges required to retrieve a large amount of
management information by returning a series of variable bindings
in a single response. The requester is required to specify a "max-
repetitions" count, and the agent then fills in as many variable
bindings as it can without exceeding either this count, or the
maximum message size.

The main problem with retrieving tables using GetBulkRequest is
that the manager typically does not know the number of rows in the
table, and hence cannot set max-repetitions to the optimal value.
As a result, the manager must either set max-repetitions to some
huge value, resulting in a potentially large waste of bandwidth
when many more variable bindings are returned than are needed
(sometimes called "overshoot"), or else must issue multiple
GetBulkRequests sequentially to traverse a large table such as the
routing table in a backbone router.

This document describes a MIB that can be used by an application
to retrieve MIB information in a more efficient way without any
change to the SNMP protocol or SNMP protocol engines. This
operation, referred to as a "GetSubtree" request, allows a manager
to request the agent to retrieve a subtree of MIB data starting at
the root OID (specified by the manager) and including all object





Expires May 2001                                          [Page 3]


Draft                     GET-SUBTREE MIB            November 2000


instances whose OID is prefixed by the root OID. The manager is
also provided the facility to specify several subtrees of data to
be retrieved in parallel by the agent.

This approach eliminates the guesswork involved in using the
GetBulkRequest operation and makes good use of bandwidth as only
those MIB objects of interest to the manager are retrieved (albeit
with some overhead).


3.1.  Structure of the MIB

This MIB consists of two tables:

o    getSubtreeRootTable - this table stores the root OID(s) of
     the subtree(s) to be retrieved. Rows in this table are
     indexed by getSubtreeRootOperationID which uniquely
     identifies the retrieval operation in progress, and a
     secondary index (getSubtreeRootOIDIndex) which identifies the
     root OIDs associated with the request.

o    getSubtreeControlTable - this table stores the main
     getSubtree request information. The manager must create a row
     which identifies the application (represented by an entry in
     the snmpTargetAddrTable) as the response destination. Rows in
     this table are indexed by getSubtreeRootOperationID from the
     getSubtreeRootTable.

     Note: The application must have been pre-configured as a
     legal notification target in the SNMP-TARGET-MIB [14].


3.2.  Operation

To set up a retrieval, an application issues a SetRequest to
perform a row creation in the getSubtreeRootTable using an
arbitrarily selected value for the primary index
(getSubtreeRootOperationID), a value of "1" for the secondary
index (getSubtreeRootOIDIndex), and the root OID of the subtree to
be retrieved. If the application wishes to retrieve multiple
subtrees simultaneously, it may do so by creating additional rows
for each subtree's root OID using the same primary index value and
sequentially increasing values for getSubtreeRootOIDIndex. The
purpose of starting the secondary index values at "1" for each new
GetSubtree operation is to avoid concurrency problems if another





Expires May 2001                                          [Page 4]


Draft                     GET-SUBTREE MIB            November 2000


management application happens to select the same value of the
primary index for creating its rows in this table. Note that
creating rows in the getSubtreeRootTable in itself does not start
the retrieval process.

The manager must then create a row in the getSubtreeControlTable
using the same value of getSubtreeRootOperationID as the index and
identifying itself via the getSubtreeControlTarget object.
Creating a row in this table triggers the agent to begin sending
traps containing the requested information to the application, so
long as there are one or more entries in the getSubtreeRootTable
indexed by the same value of getSubtreeRootOperationID. If there
are no such entries, then this newly created row in the
getSubtreeControlTable will be deleted automatically by the agent.
It may also be that a manager may make one or more rows in the
getSubtreeRootTable and fail to make any entries in the
getSubtreeControlTable to drive the operation. In this case, the
agent may choose what to do with these "orphaned" entries. Options
include, but are not limited to: letting them exist indefinitely;
deleting them after some timeout period has elapsed; or deleting
them if there is a resource shortage. The choice is implementation
dependent.

Each trap generated by the agent contains a sequence number object
(which can be used to detect losses), a counter object, a flag
object signalling whether the trap is the final one in the
sequence, and a series of varbinds containing the next chunk from
the requested subtree. The agent will send as many varbinds in the
trap as possible without exceeding the maximum message size and
without going beyond the subtree. Multiple traps will be sent
until the entire subtree has been retrieved. If more than one
subtree has been requested, the agent will send repetitions
containing varbinds from each subtree until all subtrees have been
retrieved. The agent must ensure that each trap contains only an
integral number of repetitions.

If a manager detects a lost trap (or a sequence of lost traps), it
can request that portion of the subtree to be retransmitted using
a GetBulkRequest. The counter in each trap indicates the number of
repetitions transmitted thus far (including those sent in the
current trap). A management application can use this counter as a
hint when selecting a value for the max-repetitions field in the
GetBulkRequest when sending the retransmission request.

Once the entire retrieval operation is complete, the request will





Expires May 2001                                          [Page 5]


Draft                     GET-SUBTREE MIB            November 2000


be deleted from getSubtreeControlTable along with all its
corresponding rows in getSubtreeRootTable.

Furthermore, if the request was in error (e.g., a human entered a
different OID from what was intended, causing the application to
receive large amounts of unwanted data), the MIB also provides a
way to halt an operation in progress, if the agent is able to
support this. Halting an operation in progress is accomplished
simply by allowing the application to delete the conceptual row in
getSubtreeControlTable corresponding to the outstanding operation.
If the retrieval operation is successfully aborted, the agent will
also automatically delete the rows from getSubtreeRootTable
corresponding to that operation.


3.3.  Limitations

The limitations of this approach that come with not changing SNMP
include:

o    To use this MIB to retrieve subtrees of information, the
     application must be able to issue SETs (at least to this
     MIB), not just GETs.

o    The command responder and notification originator need to be
     tightly coupled, as well as the command generator and
     notification responder.

o    The subagent implementing this MIB must be able to call back
     into the SNMP engine to walk other MIBs, without causing a
     deadlock.



















Expires May 2001                                          [Page 6]


Draft                     GET-SUBTREE MIB            November 2000


4.  Definitions

GET-SUBTREE-MIB DEFINITIONS ::= BEGIN

IMPORTS
    MODULE-IDENTITY, OBJECT-TYPE,
    NOTIFICATION-TYPE, Unsigned32,
    Counter32                 FROM SNMPv2-SMI
    RowStatus, TruthValue               FROM SNMPv2-TC
    MODULE-COMPLIANCE, OBJECT-GROUP,
    NOTIFICATION-GROUP                  FROM SNMPv2-CONF
    SnmpAdminString                     FROM SNMP-FRAMEWORK-MIB;


getSubtreeMIB MODULE-IDENTITY
    LAST-UPDATED "0010201200Z"
    ORGANIZATION "IRTF Network Management Research Group"
    CONTACT-INFO
            "Dave Thaler
             Microsoft Corporation
             One Microsoft Way
             Redmond, WA 98052-6399
             EMail: dthaler@microsoft.com

             Satyen Chandragiri
             Lucent Technologies, Inc.
             101 Crawfords Corner Road
             Holmdel, NJ 07733-3030
             EMail: satyen@lucent.com"
    DESCRIPTION
            "This MIB module provides the ability to retrieve
            arbitrary subtrees of OIDs (in parallel) by receiving
            traps."
    ::= { XXX }

getSubtreeMIBObjects OBJECT IDENTIFIER ::= { getSubtreeMIB 1 }

getSubtree       OBJECT IDENTIFIER ::= { getSubtreeMIBObjects 1 }
getSubtreeTraps      OBJECT IDENTIFIER ::= { getSubtreeMIBObjects 2 }

--
-- GetSubtree Root Table
--

getSubtreeRootTable OBJECT-TYPE





Expires May 2001                                          [Page 7]


Draft                     GET-SUBTREE MIB            November 2000


    SYNTAX     SEQUENCE OF GetSubtreeRootEntry
    MAX-ACCESS not-accessible
    STATUS     current
    DESCRIPTION
            "The (conceptual) table containing the root OID(s) of
            the MIB subtree(s) to be retrieved. Multiple rows with
            different values for getSubtreeRootOID may be created
            if the manager wishes to retrieve several subtrees
            simultaneously"
    ::= { getSubtree 1 }

getSubtreeRootEntry OBJECT-TYPE
    SYNTAX     GetSubtreeRootEntry
    MAX-ACCESS not-accessible
    STATUS     current
    DESCRIPTION
            "An entry (conceptual row) specifying the root OID of
            the MIB subtree to be retrieved"
    INDEX { getSubtreeRootOperationID, getSubtreeRootOIDIndex }
    ::=   { getSubtreeRootTable 1 }

GetSubtreeRootEntry ::= SEQUENCE {
    getSubtreeRootOperationID Unsigned32,
    getSubtreeRootOIDIndex    Unsigned32,
    getSubtreeRootOID         OBJECT IDENTIFIER,
    getSubtreeRootStatus RowStatus
}

getSubtreeRootOperationID OBJECT-TYPE
    SYNTAX          Unsigned32
    MAX-ACCESS      not-accessible
    STATUS          current
    DESCRIPTION
            "An integer uniquely identifying the GetSubtree
            operation in progress. This value should be randomly
            generated by a manager before attempting to create the
            row."
    ::= { getSubtreeRootEntry 1 }

getSubtreeRootOIDIndex OBJECT-TYPE
    SYNTAX          Unsigned32
    MAX-ACCESS      not-accessible
    STATUS          current
    DESCRIPTION
            "An index value used to associate various root OIDs





Expires May 2001                                          [Page 8]


Draft                     GET-SUBTREE MIB            November 2000


            with the same GetSubtree operation. This value should
            be one for the first entry associated with a
            particular retrieval operation and should be
            sequentially incremented for each additional entry."
    ::= { getSubtreeRootEntry 2 }

getSubtreeRootOID OBJECT-TYPE
    SYNTAX          OBJECT IDENTIFIER
    MAX-ACCESS      read-create
    STATUS          current
    DESCRIPTION
            "The root OID of the subtree to be retrieved."
    ::= { getSubtreeRootEntry 3 }

getSubtreeRootStatus OBJECT-TYPE
    SYNTAX     RowStatus
    MAX-ACCESS read-create
    STATUS     current
    DESCRIPTION
            "The status of this row. The manager should create one
            row for each subtree to be retrieved. After the entire
            subtree retrieval operation is completed (or if the
            operation is aborted by the user) all rows in this
            table corresponding to that operation are
            automatically deleted by the agent.

            Objects in this table cannot be modified while a
            GetSubtree retrieval operation is in progress."
    ::= { getSubtreeRootEntry 4 }


--
-- GetSubtree Control Table
--

getSubtreeControlTable OBJECT-TYPE
    SYNTAX          SEQUENCE OF GetSubtreeControlEntry
    MAX-ACCESS      not-accessible
    STATUS          current
    DESCRIPTION
            "The (conceptual) table used to control GetSubtree
            operations in progress. This table is used in
            conjunction with getSubtreeRootTable.

            A manager interested in retrieving a subtree of MIB





Expires May 2001                                          [Page 9]


Draft                     GET-SUBTREE MIB            November 2000


            objects must first create an entry in the
            getSubtreeRootTable specifying the root OID (s) of the
            subtree(s) to be retrieved. It must then make a
            corresponding entry in this table using the same
            getSubtreeRootOperationID value and identifying itself
            (via getSubtreeControlTarget) as the recipient of the
            traps.

            When the agent completes retrieval of all MIB
            instances within the specified subtree(s) this
            conceptual row will be automatically deleted."
    ::= { getSubtree 2 }

getSubtreeControlEntry OBJECT-TYPE
    SYNTAX          GetSubtreeControlEntry
    MAX-ACCESS      not-accessible
    STATUS          current
    DESCRIPTION
            "An entry (conceptual row) containing the information
            on a particular GetSubtree operation in progress."
    INDEX           { getSubtreeRootOperationID }
    ::= { getSubtreeControlTable 1 }

GetSubtreeControlEntry ::= SEQUENCE {
    getSubtreeControlTarget    SnmpAdminString,
    getSubtreeControlSeqNumber Counter32,
    getSubtreeControlCount     Counter32,
    getSubtreeControlDone      TruthValue,
    getSubtreeControlStatus    RowStatus
}

getSubtreeControlTarget OBJECT-TYPE
    SYNTAX          SnmpAdminString
    MAX-ACCESS      read-create
    STATUS          current
    DESCRIPTION
            "This object selects a management target defined in
            the snmpTargetAddrTable (in the SNMP-TARGET-MIB).  The
            selected target is defined by an entry in the
            snmpTargetAddrTable whose index value
            (snmpTargetAddrName) is equal to this object."
    ::= { getSubtreeControlEntry 2 }

getSubtreeControlSeqNumber OBJECT-TYPE
    SYNTAX          Counter32





Expires May 2001                                         [Page 10]


Draft                     GET-SUBTREE MIB            November 2000


    MAX-ACCESS      read-only
    STATUS          current
    DESCRIPTION
            "The number of trap responses previously sent for this
            GetSubtree request."
    ::= { getSubtreeControlEntry 3 }

getSubtreeControlCount OBJECT-TYPE
    SYNTAX          Counter32
    MAX-ACCESS      read-only
    STATUS          current
    DESCRIPTION
            "The number of repetitions transmitted thus far (up to
            and including those sent in the current trap)"
    ::= { getSubtreeControlEntry 4 }

getSubtreeControlDone OBJECT-TYPE
    SYNTAX          TruthValue
    MAX-ACCESS      read-only
    STATUS     current
    DESCRIPTION
            "This is set to true in the last trap sent, and is set
            to false otherwise."
    ::= { getSubtreeControlEntry 5 }

getSubtreeControlStatus OBJECT-TYPE
    SYNTAX          RowStatus
    MAX-ACCESS      read-create
    STATUS          current
    DESCRIPTION
            "The status of this row, by which new entries may be
            created, or old entries deleted from this table.  Once
            created, the row may be deleted, but other objects in
            the row may not be modified.  A row (and corresponding
            rows in the getSubtreeRootTable) will be deleted
            automatically by the agent once the operation has
            completed. A row may be created using an instance
            value for getSubtreeRootOperationID even if no entries
            exist in getSubtreeRootTable indexed by that value.

            Creating a row will cause the subtree retrieval
            operation to commence if there are entries in the
            getSubtreeRootTable indexed by the same value of
            getSubtreeRootOperationID as this row. If the agent
            allows aborting operations in progress, deleting a row





Expires May 2001                                         [Page 11]


Draft                     GET-SUBTREE MIB            November 2000


            will cause the operation to halt. If the operation is
            successfully aborted, the rows in the
            getSubtreeRootTable corresponding to this request will
            also be automatically deleted by the agent."
    ::= { getSubtreeControlEntry 6 }


-- traps

getSubtreeTrapPrefix OBJECT IDENTIFIER ::= { getSubtreeTraps 0 }

getSubtreeResponse NOTIFICATION-TYPE
    OBJECTS     {
                  getSubtreeControlSeqNumber,
                  getSubtreeControlCount,
                  getSubtreeControlDone
                }
    STATUS current
    DESCRIPTION
            "In addition to the three objects above, this trap
            also contains a series of varbinds containing the next
            chunk of the subtree.  The generating entity will
            append, in order, as many variables to the variable-
            bindings field as it can without exceeding the maximum
            message size, and without going beyond the subtree of
            OIDs requested.  A series of such traps will be
            generated until the end of the subtree is reached."
    ::= { getSubtreeTrapPrefix 1 }

-- conformance information

getSubtreeMIBConformance
                  OBJECT IDENTIFIER ::= { getSubtreeMIB 2 }
getSubtreeMIBCompliances
                  OBJECT IDENTIFIER ::= { getSubtreeMIBConformance 1 }
getSubtreeMIBGroups  OBJECT IDENTIFIER ::= { getSubtreeMIBConformance 2 }

-- compliance statements

getSubtreeMIBCompliance MODULE-COMPLIANCE
    STATUS  current
    DESCRIPTION
            "The compliance statement for the GetSubtree MIB."
    MODULE  -- this module
    MANDATORY-GROUPS {





Expires May 2001                                         [Page 12]


Draft                     GET-SUBTREE MIB            November 2000


            getSubtreeObjectGroup,
            getSubtreeNotificationGroup
                     }
   ::= { getSubtreeMIBCompliances 1 }

-- units of conformance

getSubtreeObjectGroup OBJECT-GROUP
    OBJECTS     {
                  getSubtreeRootOID,
                  getSubtreeRootStatus,
                  getSubtreeControlTarget,
                  getSubtreeControlSeqNumber,
                  getSubtreeControlCount,
                  getSubtreeControlDone,
                  getSubtreeControlStatus
                }
    STATUS  current
    DESCRIPTION
            "A collection of objects to support requests for
            subtree retrieval operations."
    ::= { getSubtreeMIBGroups 1 }

getSubtreeNotificationGroup NOTIFICATION-GROUP
    NOTIFICATIONS { getSubtreeResponse }
    STATUS  current
    DESCRIPTION
            "The notification which an entity is required to
            implement."
    ::= { getSubtreeMIBGroups 2 }

END


















Expires May 2001                                         [Page 13]


Draft                     GET-SUBTREE MIB            November 2000


5.  Security Considerations

While unauthorized read access to the objects in this MIB is
relatively innocuous, unauthorized write access could trigger
sending of a potentially large amount of data to an authorized
notification receiver, which could be viewed as a denial-of-
service attack.

Hence, the support for SNMP operations in a non-secure environment
without proper protection can have a negative effect on network
operations.

SNMPv1 by itself is such an insecure environment. Even if the
network itself is secure (for example by using IPSec [16]), even
then, there is no control as to who on the secure network is
allowed to access and SET (change/create/delete) the objects in
this MIB.

It is recommended that the implementers consider the security
features as provided by the SNMPv3 framework. Specifically, the
use of the User-based Security Model RFC 2274 [12] and the View-
based Access Control Model RFC 2275 [15] is recommended.

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


6.  Authors' Addresses

     Dave Thaler
     Microsoft Corporation
     One Microsoft Way
     Redmond, WA 98052-6399
     Phone: +1 425 703 8835
     EMail: dthaler@microsoft.com

     Satyen Chandragiri
     Lucent Technologies, Inc.
     101 Crawfords Corner Road
     Holmdel, NJ 07733-3030
     Phone: +1 732 949 2080
     EMail: satyen@lucent.com






Expires May 2001                                         [Page 14]


Draft                     GET-SUBTREE MIB            November 2000


7.  References

[1]  Wijnen, B., Harrington, D., and R. Presuhn, "An Architecture
     for Describing SNMP Management Frameworks", RFC 2571,
     Cabletron Systems, Inc., BMC Software, Inc., IBM T. J. Watson
     Research, April 1999.

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

[3]  Rose, M., and K. McCloghrie, "Concise MIB Definitions", STD
     16, RFC 1212, Performance Systems International, Hughes LAN
     Systems, March 1991.

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

[5]  McCloghrie, K., Perkins, D., and J. Schoenwaelder, "Structure
     of Management Information Version 2 (SMIv2)", STD 58, RFC
     2578, April 1999.

[6]  McCloghrie, K., Perkins, D., and J. Schoenwaelder, "Textual
     Conventions for SMIv2", STD 58, RFC 2579, April 1999.

[7]  McCloghrie, K., Perkins, D., and J. Schoenwaelder,
     "Conformance Statements for SMIv2", STD 58, RFC 2580, April
     1999.

[8]  Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple
     Network Management Protocol", STD 15, RFC 1157, SNMP
     Research, Performance Systems International, Performance
     Systems International, MIT Laboratory for Computer Science,
     May 1990.

[9]  Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
     "Introduction to Community-based SNMPv2", RFC 1901, SNMP
     Research, Inc., Cisco Systems, Inc., Dover Beach Consulting,
     Inc., International Network Services, January 1996.

[10] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
     "Transport Mappings for Version 2 of the Simple Network
     Management Protocol (SNMPv2)", RFC 1906, SNMP Research, Inc.,





Expires May 2001                                         [Page 15]


Draft                     GET-SUBTREE MIB            November 2000


     Cisco Systems, Inc., Dover Beach Consulting, Inc.,
     International Network Services, January 1996.

[11] Case, J., Harrington D., Presuhn R., and B. Wijnen, "Message
     Processing and Dispatching for the Simple Network Management
     Protocol (SNMP)", RFC 2572, SNMP Research, Inc., Cabletron
     Systems, Inc., BMC Software, Inc., IBM T. J. Watson Research,
     April 1999.

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

[13] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
     "Protocol Operations for Version 2 of the Simple Network
     Management Protocol (SNMPv2)", RFC 1905, SNMP Research, Inc.,
     Cisco Systems, Inc., Dover Beach Consulting, Inc.,
     International Network Services, January 1996.

[14] Levi, D., Meyer, P., and B. Stewart, "SNMPv3 Applications",
     RFC 2573, SNMP Research, Inc., Secure Computing Corporation,
     Cisco Systems, April 1999.

[15] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based
     Access Control Model (VACM) for the Simple Network Management
     Protocol (SNMP)", RFC 2575, IBM T. J. Watson Research, BMC
     Software, Inc., Cisco Systems, Inc., April 1999.


8.  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 implmentation 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





Expires May 2001                                         [Page 16]


Draft                     GET-SUBTREE MIB            November 2000


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.







































Expires May 2001                                         [Page 17]