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Versions: 00

IPv6 MIB Revision Design Team                    Bill Fenner
INTERNET-DRAFT                                 AT&T Research
Expires: August 2001                          Brian Haberman
                                             Nortel Networks
                                            Keith McCloghrie
                                               Cisco Systems
                                        Juergen Schoenwalder
                                             TU Braunschweig
                                                 Dave Thaler
                                                   Microsoft
                                               February 2001


                      Management Information Base
              for the Transmission Control Protocol (TCP)
                    draft-ops-rfc2012-update-00.txt

Status of this Document

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.


This document is a product of the IPv6 MIB Revision Design Team.
Comments should be addressed to the authors, or the mailing list at
ipv6mib@ibr.cs.tu-bs.de.

Copyright Notice

Copyright (C) The Internet Society (2001). All Rights Reserved.






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                                Abstract

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 implementations of the
Transmission Control Protocol (TCP) [5] in an IP version independent
manner.

                           Table of Contents


1. The SNMP Management Framework . . . . . . . . . . . . . . . . . .   2
2. Revision History. . . . . . . . . . . . . . . . . . . . . . . . .   3
3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
4. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . . .  15
5. Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . .  15
6. References. . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
7. Security Considerations . . . . . . . . . . . . . . . . . . . . .  17
8. Editor's Address. . . . . . . . . . . . . . . . . . . . . . . . .  18
9. Full Copyright Statement. . . . . . . . . . . . . . . . . . . . .  18


1.  The SNMP Management Framework

The SNMP Management Framework presently consists of five major
components:

o An overall architecture, described in RFC 2571 [7].

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 [8], STD 16, RFC 1212 [9] and RFC 1215 [10]. The second
  version, called SMIv2, is described in STD 58, RFC 2578 [11], STD 58,
  RFC 2579 [12] and STD 58, RFC 2580 [13].

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 [14]. A second version of the SNMP message protocol,
  which is not an Internet standards track protocol, is called SNMPv2c
  and described in RFC 1901 [15] and RFC 1906 [16]. The third version of
  the message protocol is called SNMPv3 and described in RFC 1906 [16],
  RFC 2572 [17] and RFC 2574 [18].

o Protocol operations for accessing management information.  The first
  set of protocol operations and associated PDU formats is described in
  STD 15, RFC 1157 [14]. A second set of protocol operations and
  associated PDU formats is described in RFC 1905 [19].



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o A set of fundamental applications described in RFC 2573 [20] and the
  view-based access control mechanism described in RFC 2575 [21].

A more detailed introduction to the current SNMP Management Framework
can be found in RFC 2570 [22].

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.


2.  Revision History

Changes from first draft posted to v6mib mailing list:

23 Feb 2001

     Made threshold for HC packet counters 1Mpps

     Added copyright statements and table of contents

21 Feb 2001 -- Juergen's changes

     Renamed tcpInetConn* to tcpConnection*

     Updated Conformance info

     Added missing tcpConnectionState and tcpConnState objects to
     SEQUENCEs

6 Feb 2001

     Removed v6-only objects.

     Renamed inetTcp* to tcpInet*

     Added SIZE restriction to InetAddress index objects.  (36 = 32-byte
     addresses plus 4-byte scope, but it's just a strawman)



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     Used InetPortNumber TC from updated INET-ADDRESS-MIB

     Updated compliance statements.

     Added Keith to authors

     Added open issues section.


3.  Definitions

TCP-MIB DEFINITIONS ::= BEGIN

IMPORTS
    MODULE-IDENTITY, OBJECT-TYPE, Integer32, Gauge32,
    Counter32, Counter64, IpAddress, mib-2
                                       FROM SNMPv2-SMI
    MODULE-COMPLIANCE, OBJECT-GROUP    FROM SNMPv2-CONF
    InetAddress, InetAddressType,
    InetPortNumber                     FROM INET-ADDRESS-MIB;

tcpMIB MODULE-IDENTITY
    LAST-UPDATED "200102210000Z"
    ORGANIZATION "IETF IPv6 MIB Revision Team"
    CONTACT-INFO
           "Bill Fenner (editor)

            AT&T Labs -- Research
            75 Willow Rd.
            Menlo Park, CA 94025

            Phone: +1 650 330-7893
            Email: <fenner@research.att.com>"
    DESCRIPTION
           "The MIB module for managing TCP implementations."
    REVISION      "200102210000Z"
    DESCRIPTION
           "IP version neutral revision, published as RFC XXXX."
    REVISION      "9411010000Z"
    DESCRIPTION
           "Initial SMIv2 version, published as RFC 2012."
    REVISION      "9103310000Z"
    DESCRIPTION
           "The initial revision of this MIB module was part of MIB-II."
    ::= { mib-2 49 }


-- the TCP base variables group



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tcp      OBJECT IDENTIFIER ::= { mib-2 6 }

-- Scalars

tcpRtoAlgorithm OBJECT-TYPE
    SYNTAX      INTEGER {
                    other(1),    -- none of the following
                    constant(2), -- a constant rto
                    rsre(3),     -- MIL-STD-1778, Appendix B
                    vanj(4)      -- Van Jacobson's algorithm [1]
                }
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The algorithm used to determine the timeout value used for
            retransmitting unacknowledged octets."
    ::= { tcp 1 }

tcpRtoMin OBJECT-TYPE
    SYNTAX     Integer32
    UNITS       "milliseconds"
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The minimum value permitted by a TCP implementation for the
            retransmission timeout, measured in milliseconds.  More
            refined semantics for objects of this type depend upon the
            algorithm used to determine the retransmission timeout.  In
            particular, when the timeout algorithm is rsre(3), an object
            of this type has the semantics of the LBOUND quantity
            described in RFC 793."
    ::= { tcp 2 }

tcpRtoMax OBJECT-TYPE
    SYNTAX     Integer32
    UNITS       "milliseconds"
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The maximum value permitted by a TCP implementation for the
            retransmission timeout, measured in milliseconds.  More
            refined semantics for objects of this type depend upon the
            algorithm used to determine the retransmission timeout.  In
            particular, when the timeout algorithm is rsre(3), an object
            of this type has the semantics of the UBOUND quantity
            described in RFC 793."
    ::= { tcp 3 }




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tcpMaxConn OBJECT-TYPE
    SYNTAX     Integer32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The limit on the total number of TCP connections the entity
            can support.  In entities where the maximum number of
            connections is dynamic, this object should contain the value
            -1."
    ::= { tcp 4 }

tcpActiveOpens OBJECT-TYPE
    SYNTAX     Counter32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The number of times TCP connections have made a direct
            transition to the SYN-SENT state from the CLOSED state."
    ::= { tcp 5 }

tcpPassiveOpens OBJECT-TYPE
    SYNTAX     Counter32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The number of times TCP connections have made a direct
            transition to the SYN-RCVD state from the LISTEN state."
    ::= { tcp 6 }

tcpAttemptFails OBJECT-TYPE
    SYNTAX     Counter32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The number of times TCP connections have made a direct
            transition to the CLOSED state from either the SYN-SENT
            state or the SYN-RCVD state, plus the number of times TCP
            connections have made a direct transition to the LISTEN
            state from the SYN-RCVD state."
    ::= { tcp 7 }

tcpEstabResets OBJECT-TYPE
    SYNTAX     Counter32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The number of times TCP connections have made a direct
            transition to the CLOSED state from either the ESTABLISHED



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            state or the CLOSE-WAIT state."
    ::= { tcp 8 }

tcpCurrEstab OBJECT-TYPE
    SYNTAX     Gauge32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The number of TCP connections for which the current state is
            either ESTABLISHED or CLOSE-WAIT."
    ::= { tcp 9 }


tcpInSegs OBJECT-TYPE
    SYNTAX     Counter32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The total number of segments received, including those
            received in error.  This count includes segments received on
            currently established connections."
    ::= { tcp 10 }

tcpOutSegs OBJECT-TYPE
    SYNTAX     Counter32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The total number of segments sent, including those on
            current connections but excluding those containing only
            retransmitted octets."
    ::= { tcp 11 }

tcpRetransSegs OBJECT-TYPE
    SYNTAX     Counter32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The total number of segments retransmitted - that is, the
            number of TCP segments transmitted containing one or more
            previously transmitted octets."
    ::= { tcp 12 }

tcpInErrs OBJECT-TYPE
    SYNTAX     Counter32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION



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           "The total number of segments received in error (e.g., bad
            TCP checksums)."
    ::= { tcp 14 }

tcpOutRsts OBJECT-TYPE
    SYNTAX     Counter32
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The number of TCP segments sent containing the RST flag."
    ::= { tcp 15 }

tcpHCInSegs OBJECT-TYPE
    SYNTAX     Counter64
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The total number of segments received, including those
            received in error, on systems that can receive more than 1
            million TCP packets per second.  This count includes
            segments received on currently established connections."
    ::= { tcp 17 }

tcpHCOutSegs OBJECT-TYPE
    SYNTAX     Counter64
    MAX-ACCESS read-only
    STATUS     current
    DESCRIPTION
           "The total number of segments sent, including those on
            current connections but excluding those containing only
            retransmitted octets, on systems that can transmit more than
            1 million TCP packets per second."
    ::= { tcp 18 }

-- The TCP Connection table

tcpConnectionTable OBJECT-TYPE
    SYNTAX     SEQUENCE OF TcpConnectionEntry
    MAX-ACCESS not-accessible
    STATUS     current
    DESCRIPTION
           "A table containing information about existing TCP
            connections or listeners."
    ::= { tcp 19 }

tcpConnectionEntry OBJECT-TYPE
    SYNTAX     TcpConnectionEntry
    MAX-ACCESS not-accessible



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    STATUS     current
    DESCRIPTION
           "A conceptual row of the tcpConnectionTable containing
            information about a particular current TCP connection.  Each
            row of this table is transient, in that it ceases to exist
            when (or soon after) the connection makes the transition to
            the CLOSED state."
    INDEX   { tcpConnectionLocalAddressType,
              tcpConnectionLocalAddress,
              tcpConnectionLocalPort,
              tcpConnectionRemAddressType,
              tcpConnectionRemAddress,
              tcpConnectionRemPort }
    ::= { tcpConnectionTable 1 }

TcpConnectionEntry ::= SEQUENCE {
        tcpConnectionLocalAddressType  InetAddressType,
        tcpConnectionLocalAddress      InetAddress,
        tcpConnectionLocalPort         InetPortNumber,
        tcpConnectionRemAddressType    InetAddressType,
        tcpConnectionRemAddress        InetAddress,
        tcpConnectionRemPort           InetPortNumber,
        tcpConnectionState             INTEGER
    }

tcpConnectionLocalAddressType OBJECT-TYPE
    SYNTAX     InetAddressType
    MAX-ACCESS not-accessible
    STATUS     current
    DESCRIPTION
           "The address type of tcpConnectionLocalAddress.  Only IPv4
            and IPv6 addresses are expected."
    ::= { tcpConnectionEntry 1 }

tcpConnectionLocalAddress OBJECT-TYPE
    SYNTAX     InetAddress (SIZE(0..36))
    MAX-ACCESS not-accessible
    STATUS     current
    DESCRIPTION
           "The local IP address for this TCP connection.  In the case
            of a connection in the listen state which is willing to
            accept connections for any IP interface associated with the
            node, a value of all zeroes is used."
    ::= { tcpConnectionEntry 2 }

tcpConnectionLocalPort OBJECT-TYPE
    SYNTAX     InetPortNumber
    MAX-ACCESS not-accessible



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    STATUS     current
    DESCRIPTION
           "The local port number for this TCP connection."
    ::= { tcpConnectionEntry 3 }

tcpConnectionRemAddressType OBJECT-TYPE
    SYNTAX     InetAddressType
    MAX-ACCESS not-accessible
    STATUS     current
    DESCRIPTION
           "The address type of tcpConnectionRemAddress.  Only IPv4 and
            IPv6 addresses are expected.  Must be the same as
            tcpConnectionLocalAddressType."
    ::= { tcpConnectionEntry 4 }

tcpConnectionRemAddress OBJECT-TYPE
    SYNTAX     InetAddress (SIZE(0..36))
    MAX-ACCESS not-accessible
    STATUS     current
    DESCRIPTION
           "The remote IP address for this TCP connection."
    ::= { tcpConnectionEntry 5 }

tcpConnectionRemPort OBJECT-TYPE
    SYNTAX     InetPortNumber
    MAX-ACCESS not-accessible
    STATUS     current
    DESCRIPTION
           "The remote port number for this TCP connection."
    ::= { tcpConnectionEntry 6 }

tcpConnectionState OBJECT-TYPE
    SYNTAX     INTEGER {
                    closed(1),
                    listen(2),
                    synSent(3),
                    synReceived(4),
                    established(5),
                    finWait1(6),
                    finWait2(7),
                    closeWait(8),
                    lastAck(9),
                    closing(10),
                    timeWait(11),
                    deleteTCB(12)
                }
    MAX-ACCESS read-write
    STATUS     current



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    DESCRIPTION
           "The state of this TCP connection.

            The only value which may be set by a management station is
            deleteTCB(12).  Accordingly, it is appropriate for an agent
            to return a `badValue' response if a management station
            attempts to set this object to any other value.

            If a management station sets this object to the value
            deleteTCB(12), then this has the effect of deleting the TCB
            (as defined in RFC 793) of the corresponding connection on
            the managed node, resulting in immediate termination of the
            connection.

            As an implementation-specific option, a RST segment may be
            sent from the managed node to the other TCP endpoint (note
            however that RST segments are not sent reliably)."
    ::= { tcpConnectionEntry 7 }


-- The deprecated TCP Connection table

tcpConnTable OBJECT-TYPE
    SYNTAX     SEQUENCE OF TcpConnEntry
    MAX-ACCESS not-accessible
    STATUS     deprecated
    DESCRIPTION
           "A table containing information about existing IPv4-specific
            TCP connections or listeners.  This table has been
            deprecated in favor of the version neutral
            tcpConnectionTable."
    ::= { tcp 13 }

tcpConnEntry OBJECT-TYPE
    SYNTAX     TcpConnEntry
    MAX-ACCESS not-accessible
    STATUS     deprecated
    DESCRIPTION
           "A conceptual row of the tcpConnTable containing information
            about a particular current IPv4 TCP connection.  Each row of
            this table is transient, in that it ceases to exist when (or
            soon after) the connection makes the transition to the
            CLOSED state."
    INDEX   { tcpConnLocalAddress,
              tcpConnLocalPort,
              tcpConnRemAddress,
              tcpConnRemPort }
    ::= { tcpConnTable 1 }



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TcpConnEntry ::= SEQUENCE {
        tcpConnState         INTEGER,
        tcpConnLocalAddress  IpAddress,
        tcpConnLocalPort     INTEGER,
        tcpConnRemAddress    IpAddress,
        tcpConnRemPort       INTEGER
    }

tcpConnState OBJECT-TYPE
    SYNTAX     INTEGER {
                    closed(1),
                    listen(2),
                    synSent(3),
                    synReceived(4),
                    established(5),
                    finWait1(6),
                    finWait2(7),
                    closeWait(8),
                    lastAck(9),
                    closing(10),
                    timeWait(11),
                    deleteTCB(12)
                }
    MAX-ACCESS read-write
    STATUS     deprecated
    DESCRIPTION
           "The state of this TCP connection.

            The only value which may be set by a management station is
            deleteTCB(12).  Accordingly, it is appropriate for an agent
            to return a `badValue' response if a management station
            attempts to set this object to any other value.

            If a management station sets this object to the value
            deleteTCB(12), then this has the effect of deleting the TCB
            (as defined in RFC 793) of the corresponding connection on
            the managed node, resulting in immediate termination of the
            connection.

            As an implementation-specific option, a RST segment may be
            sent from the managed node to the other TCP endpoint (note
            however that RST segments are not sent reliably)."
    ::= { tcpConnEntry 1 }

tcpConnLocalAddress OBJECT-TYPE
    SYNTAX     IpAddress
    MAX-ACCESS read-only
    STATUS     deprecated



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    DESCRIPTION
           "The local IP address for this TCP connection.  In the case
            of a connection in the listen state which is willing to
            accept connections for any IP interface associated with the
            node, the value 0.0.0.0 is used."
    ::= { tcpConnEntry 2 }

tcpConnLocalPort OBJECT-TYPE
    SYNTAX     INTEGER (0..65535)
    MAX-ACCESS read-only
    STATUS     deprecated
    DESCRIPTION
           "The local port number for this TCP connection."
    ::= { tcpConnEntry 3 }

tcpConnRemAddress OBJECT-TYPE
    SYNTAX     IpAddress
    MAX-ACCESS read-only
    STATUS     deprecated
    DESCRIPTION
           "The remote IP address for this TCP connection."
    ::= { tcpConnEntry 4 }

tcpConnRemPort OBJECT-TYPE
    SYNTAX     INTEGER (0..65535)
    MAX-ACCESS read-only
    STATUS     deprecated
    DESCRIPTION
           "The remote port number for this TCP connection."
    ::= { tcpConnEntry 5 }




-- conformance information

tcpMIBConformance OBJECT IDENTIFIER ::= { tcpMIB 2 }

tcpMIBCompliances OBJECT IDENTIFIER ::= { tcpMIBConformance 1 }
tcpMIBGroups      OBJECT IDENTIFIER ::= { tcpMIBConformance 2 }


-- compliance statements

tcpMIBCompliance2 MODULE-COMPLIANCE
    STATUS     current
    DESCRIPTION
           "The compliance statement for systems which implement TCP."



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    MODULE  -- this module
        MANDATORY-GROUPS { tcpBaseGroup, tcpConnectionGroup }
        GROUP       tcpHCGroup
        DESCRIPTION
           "This group is mandatory for those systems which are capable
                of receiving or transmitting more than 1 million TCP
                packets per second.  1 million packets per second will
                cause a Counter32 to wrap in just over an hour."
        OBJECT      tcpConnectionState
        MIN-ACCESS  read-only
        DESCRIPTION
           "Write access is not required."
    ::= { tcpMIBCompliances 2 }

tcpMIBCompliance MODULE-COMPLIANCE
    STATUS     deprecated
    DESCRIPTION
           "The compliance statement for IPv4-only systems which
            implement TCP.  In order to be IP version independent, this
            compliance statement is deprecated in favor of
            tcpMIBCompliance2."
    MODULE  -- this module
        MANDATORY-GROUPS { tcpGroup }
        OBJECT      tcpConnState
        MIN-ACCESS  read-only
        DESCRIPTION
           "Write access is not required."
    ::= { tcpMIBCompliances 1 }

-- units of conformance

tcpGroup OBJECT-GROUP
    OBJECTS   { tcpRtoAlgorithm, tcpRtoMin, tcpRtoMax,
                tcpMaxConn, tcpActiveOpens,
                tcpPassiveOpens, tcpAttemptFails,
                tcpEstabResets, tcpCurrEstab, tcpInSegs,
                tcpOutSegs, tcpRetransSegs, tcpConnState,
                tcpConnLocalAddress, tcpConnLocalPort,
                tcpConnRemAddress, tcpConnRemPort,
                tcpInErrs, tcpOutRsts }
    STATUS     deprecated
    DESCRIPTION
           "The tcp group of objects providing for management of TCP
            entities."
    ::= { tcpMIBGroups 1 }

tcpBaseGroup OBJECT-GROUP
    OBJECTS   { tcpRtoAlgorithm, tcpRtoMin, tcpRtoMax,



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                tcpMaxConn, tcpActiveOpens,
                tcpPassiveOpens, tcpAttemptFails,
                tcpEstabResets, tcpCurrEstab, tcpInSegs,
                tcpOutSegs, tcpRetransSegs,
                tcpInErrs, tcpOutRsts }
    STATUS     current
    DESCRIPTION
           "The group of counters common to TCP entities."
    ::= { tcpMIBGroups 2 }

tcpHCGroup OBJECT-GROUP
    OBJECTS    { tcpHCInSegs, tcpHCOutSegs }
    STATUS     current
    DESCRIPTION
           "The group of objects providing for counters of high speed
            TCP implementations."
    ::= { tcpMIBGroups 3 }

tcpConnectionGroup OBJECT-GROUP
    OBJECTS   { tcpConnectionState }
    STATUS     current
    DESCRIPTION
           "The table of TCP connections."
    ::= { tcpMIBGroups 4 }

END

4.  Open Issues

Per-connection byte/segment counters?  Other stats?  [in optional
conformance group] e.g.  ConnInBytes ConnOutBytes ConnInPkts ConnOutPkts
ConnElapsed ConnSRTT

More HC counters?

v6 SIIT / IPV6_V6ONLY / ??? : does the tcpConnectionTable need
something?  (Erik said:

But for the different types of wildcard listeners it would make sense
to be able to capture the difference between:
        IPv4-only - bound to INADDR_ANY
        IPv6-only - bound to in6addr_any with the IPV6_V6ONLY socket
                    option set
        both - bound to in6addr_any and the above not set

[the last 2 could probably be differentiated by the remote address AF
being Unknown or IPv6 -- which would require changing the DESCRIPTION]




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5.  Acknowledgements

This document contains a modified subset of RFC 1213 and updates RFC
2012 and RFC 2452.


6.  References


[2] Rose, M. and K. McCloghrie, "Management Information Base for Network
     Management of TCP/IP-based internets", RFC 1213, March 1991.

[3] K. McCloghrie, "SNMPv2 Management Information Base for the
     Transmission Control Protocol using SMIv2", RFC 2012, November
     1996.

[4] Haskin, D. and S. Onishi, "IP Version 6 Management Information Base
     for the Transmission Control Protocol", RFC 2452, December 1998.

[5] Postel, J., "Transmission Control Protocol - DARPA Internet Program
     Protocol Specification", STD 7, RFC 793, DARPA, September 1981.

[6] Jacobson, V., "Congestion Avoidance and Control", SIGCOMM 1988,
     Stanford, California.

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

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

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

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

[11] 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.

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

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



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     2580, April 1999.

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

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

[16] 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.

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

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

[19] 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.

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

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

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


7.  Security Considerations


There are a number of management objects defined in this MIB that have a
MAX-ACCESS clause of read-write and/or read-create.  Such objects may be
considered sensitive or vulnerable in some network environments.  The
support for SET operations in a non-secure environment without proper
protection can have a negative effect on network operations.

There are a number of managed objects in this MIB that may contain
sensitive information. These are:




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o The tcpConnectionLocalPort and tcpConnLocalPort objects can be used to
  identify what ports are open on the machine and can thus what attacks
  are likely to succeed, without the attacker having to run a port
  scanner.

o The tcpConnectionState and tcpConnState objects have a MAX-ACCESS
  clause of read-write, which allows termination of an arbitrary
  connection.  Unauthorized access could cause a denial of service.

It is thus important to control even GET access to these objects and
possibly to even encrypt the values of these object when sending them
over the network via SNMP.  Not all versions of SNMP provide features
for such a secure environment.

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/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 2574 [18] and the View-based Access Control
Model RFC 2575 [21] is recommended.

It is then a customer/user responsibility to ensure that the SNMP entity
giving access to an instance of this 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/create/delete) them.


8.  Editor's Address


Bill Fenner
AT&T Labs -- Research
75 Willow Rd
Menlo Park, CA 94025
USA

Email: fenner@research.att.com


9.  Full Copyright Statement

Copyright (C) The Internet Society (2001). 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



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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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