RADIUS Accounting Client MIB

Network Working Group                                             B. Aboba
Request for Comments: 2620                                         G. Zorn
Category: Informational                                          Microsoft
                                                                 June 1999


                      RADIUS Accounting Client MIB

Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1999).  All Rights Reserved.

Abstract

   This memo defines a set of extensions which instrument RADIUS
   accounting client functions. These extensions represent a portion of
   the Management Information Base (MIB) for use with network management
   protocols in the Internet community.  Using these extensions IP-based
   management stations can manage RADIUS accounting clients.

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 managing RADIUS
   accounting clients.

   Today a wide range of network devices, including routers and NASes,
   act as RADIUS accounting clients in order to provide accounting
   services.  As a result, the effective management of RADIUS accounting
   clients is of considerable importance.

2.  The SNMP 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
        STD 15, RFC 1155 [2], STD 16, RFC 1212 [3] and RFC 1215 [4].
        The second version, called SMIv2, is described in STD 58, 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 STD 15, 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 STD 15, 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.

   This memo specifies a MIB module that is compliant to the SMIv2. A
   MIB conforming to the SMIv1 can be poduced 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

   The RADIUS accounting protocol, described in [16], distinguishes
   between the client function and the server function. In RADIUS
   accounting, clients send Accounting-Requests, and servers reply with
   Accounting-Responses. Typically NAS devices implement the client
   function, and thus would be expected to implement the RADIUS
   accounting client MIB, while RADIUS accounting servers implement the
   server function, and thus would be expected to implement the RADIUS
   accounting server MIB.

   However, it is possible for a RADIUS accounting entity to perform
   both client and server functions. For example, a RADIUS proxy may act
   as a server to one or more RADIUS accounting clients, while
   simultaneously acting as an accounting client to one or more
   accounting servers.  In such situations, it is expected that RADIUS
   entities combining client and server functionality will support both
   the client and server MIBs.

3.1.  Selected objects

   This MIB module contains two scalars as well as a single table:

   (1)  the RADIUS Accounting Server Table contains one row for
        each RADIUS server that the client shares a secret with.

   Each entry in the RADIUS Accounting Server Table includes thirteen
   columns presenting a view of the activity of the RADIUS client.

4.  Definitions

RADIUS-ACC-CLIENT-MIB DEFINITIONS ::= BEGIN

IMPORTS
       MODULE-IDENTITY, OBJECT-TYPE, OBJECT-IDENTITY,
       Counter32, Integer32, Gauge32,
       IpAddress, TimeTicks, mib-2      FROM SNMPv2-SMI
       SnmpAdminString                  FROM SNMP-FRAMEWORK-MIB
       MODULE-COMPLIANCE, OBJECT-GROUP  FROM SNMPv2-CONF;

radiusAccClientMIB MODULE-IDENTITY
       LAST-UPDATED "9906110000Z" -- 11 Jun 1999
       ORGANIZATION "IETF RADIUS Working Group."
       CONTACT-INFO
          " Bernard Aboba
            Microsoft
            One Microsoft Way
            Redmond, WA  98052
            US

            Phone: +1 425 936 6605
            EMail: bernarda@microsoft.com"
       DESCRIPTION
             "The MIB module for entities implementing the client side of
              the Remote Access Dialin User Service (RADIUS) accounting
              protocol."
       REVISION "9906110000Z"    -- 11 Jun 1999
       DESCRIPTION "Initial version as published in RFC 2620"
       ::= { radiusAccounting 2 }

radiusMIB OBJECT-IDENTITY
       STATUS  current
       DESCRIPTION
             "The OID assigned to RADIUS MIB work by the IANA."
       ::= { mib-2 67 }

radiusAccounting  OBJECT IDENTIFIER ::= {radiusMIB 2}

radiusAccClientMIBObjects     OBJECT IDENTIFIER ::=
                                              { radiusAccClientMIB 1 }

radiusAccClient  OBJECT IDENTIFIER ::= { radiusAccClientMIBObjects 1 }

radiusAccClientInvalidServerAddresses OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Accounting-Response packets
             received from unknown addresses."
      ::= { radiusAccClient 1 }

radiusAccClientIdentifier OBJECT-TYPE
      SYNTAX SnmpAdminString
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The NAS-Identifier of the RADIUS accounting client. This
             is not necessarily the same as sysName in MIB II."
      ::= { radiusAccClient 2 }

radiusAccServerTable OBJECT-TYPE
      SYNTAX SEQUENCE OF RadiusAccServerEntry
      MAX-ACCESS not-accessible
      STATUS     current
      DESCRIPTION
            "The (conceptual) table listing the RADIUS accounting
             servers with which the client shares a secret."
      ::= { radiusAccClient 3 }

radiusAccServerEntry OBJECT-TYPE
      SYNTAX     RadiusAccServerEntry
      MAX-ACCESS not-accessible
      STATUS     current
      DESCRIPTION
            "An entry (conceptual row) representing a RADIUS
             accounting server with which the client shares a secret."
      INDEX      { radiusAccServerIndex }
      ::= { radiusAccServerTable 1 }

RadiusAccServerEntry ::= SEQUENCE {
      radiusAccServerIndex                           Integer32,
      radiusAccServerAddress                         IpAddress,
      radiusAccClientServerPortNumber                Integer32,
      radiusAccClientRoundTripTime                   TimeTicks,
      radiusAccClientRequests                        Counter32,
      radiusAccClientRetransmissions                 Counter32,
      radiusAccClientResponses                       Counter32,
      radiusAccClientMalformedResponses              Counter32,
      radiusAccClientBadAuthenticators               Counter32,
      radiusAccClientPendingRequests                   Gauge32,
      radiusAccClientTimeouts                        Counter32,
      radiusAccClientUnknownTypes                    Counter32,
      radiusAccClientPacketsDropped                  Counter32
}

radiusAccServerIndex OBJECT-TYPE
      SYNTAX     Integer32 (1..2147483647)
      MAX-ACCESS not-accessible
      STATUS     current
      DESCRIPTION
            "A number uniquely identifying each RADIUS
             Accounting server with which this client
             communicates."
      ::= { radiusAccServerEntry 1 }

radiusAccServerAddress OBJECT-TYPE
      SYNTAX     IpAddress
      MAX-ACCESS read-only
      STATUS     current
      DESCRIPTION
            "The IP address of the RADIUS accounting server
             referred to in this table entry."
      ::= { radiusAccServerEntry 2 }

radiusAccClientServerPortNumber  OBJECT-TYPE
      SYNTAX Integer32 (0..65535)
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The UDP port the client is using to send requests to
             this server."
      ::= { radiusAccServerEntry 3 }

radiusAccClientRoundTripTime  OBJECT-TYPE
      SYNTAX TimeTicks
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
             "The time interval between the most recent
             Accounting-Response and the Accounting-Request that
             matched it from this RADIUS accounting server."
      ::= { radiusAccServerEntry 4 }

-- Request/Response statistics
--
-- Requests = Responses + PendingRequests + ClientTimeouts
--
-- Responses - MalformedResponses - BadAuthenticators -
-- UnknownTypes - PacketsDropped = Successfully received

radiusAccClientRequests OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Accounting-Request packets
             sent. This does not include retransmissions."
      ::= { radiusAccServerEntry 5 }

radiusAccClientRetransmissions OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Accounting-Request packets
             retransmitted to this RADIUS accounting server.
             Retransmissions include retries where the
             Identifier and Acct-Delay have been updated, as
             well as those in which they remain the same."
      ::= { radiusAccServerEntry 6 }

radiusAccClientResponses OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS packets received on the
             accounting port from this server."
      ::= { radiusAccServerEntry 7 }

radiusAccClientMalformedResponses OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
             "The number of malformed RADIUS Accounting-Response
              packets received from this server. Malformed packets
             include packets with an invalid length. Bad
             authenticators and unknown types are not included as
             malformed accounting responses."
      ::= { radiusAccServerEntry 8 }

radiusAccClientBadAuthenticators OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Accounting-Response
             packets which contained invalid authenticators
             received from this server."
      ::= { radiusAccServerEntry 9 }

radiusAccClientPendingRequests OBJECT-TYPE
      SYNTAX Gauge32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Accounting-Request packets
             sent to this server that have not yet timed out or
             received a response. This variable is incremented when an
             Accounting-Request is sent and decremented due to
             receipt of an Accounting-Response, a timeout or
             a retransmission."
      ::= { radiusAccServerEntry 10 }

radiusAccClientTimeouts OBJECT-TYPE
     SYNTAX Counter32
     MAX-ACCESS read-only
     STATUS current
     DESCRIPTION
          "The number of accounting timeouts to this server.
           After a timeout the client may retry to the same
           server, send to a different server, or give up.
           A retry to the same server is counted as a
           retransmit as well as a timeout. A send to a different
           server is counted as an Accounting-Request as well as
           a timeout."
      ::= { radiusAccServerEntry  11 }

radiusAccClientUnknownTypes OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS packets of unknown type which
             were received from this server on the accounting port."
      ::= { radiusAccServerEntry  12 }

radiusAccClientPacketsDropped OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS packets which were received from
             this server on the accounting port and dropped for some
             other reason."
      ::= { radiusAccServerEntry  13 }

-- conformance information

radiusAccClientMIBConformance
          OBJECT IDENTIFIER ::= { radiusAccClientMIB 2 }
radiusAccClientMIBCompliances
          OBJECT IDENTIFIER ::= { radiusAccClientMIBConformance 1 }
radiusAccClientMIBGroups
          OBJECT IDENTIFIER ::= { radiusAccClientMIBConformance 2 }

-- compliance statements

radiusAccClientMIBCompliance MODULE-COMPLIANCE
     STATUS  current
     DESCRIPTION
           "The compliance statement for accounting clients
            implementing the RADIUS Accounting Client MIB."
     MODULE  -- this module
         MANDATORY-GROUPS { radiusAccClientMIBGroup }

     ::= { radiusAccClientMIBCompliances 1 }


-- units of conformance

radiusAccClientMIBGroup OBJECT-GROUP
     OBJECTS { radiusAccClientIdentifier,
               radiusAccClientInvalidServerAddresses,
               radiusAccServerAddress,
               radiusAccClientServerPortNumber,
               radiusAccClientRoundTripTime,
               radiusAccClientRequests,
               radiusAccClientRetransmissions,
               radiusAccClientResponses,
               radiusAccClientMalformedResponses,
               radiusAccClientBadAuthenticators,
               radiusAccClientPendingRequests,
               radiusAccClientTimeouts,
               radiusAccClientUnknownTypes,
               radiusAccClientPacketsDropped
         }
     STATUS  current
     DESCRIPTION
           "The basic collection of objects providing management of
            RADIUS Accounting Clients."
     ::= { radiusAccClientMIBGroups 1 }

END

5.  References

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

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

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

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

   [5]  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.

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

   [7]  McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose,
        M. and S. Waldbusser, "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, May 1990.

   [9]  Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
        "Introduction to Community-based SNMPv2", RFC 1901, 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, 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, April 1999.

   [12] Blumenthal, U., and B. Wijnen, "User-based Security Model for
        Version 3 of the Simple Network Management Protocol (SNMPv3)",
        RFC 2574, 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, January 1996.

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

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

   [16] Rigney, C., "RADIUS Accounting", RFC 2139, April 1997.

6.  Security Considerations

   There are no management objects defined in this MIB that have a MAX-
   ACCESS clause of read-write and/or read-create.  So, if this MIB is
   implemented correctly, then there is no risk that an intruder can
   alter or create any management objects of this MIB via direct SNMP
   SET opertions.

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

   radiusAccServerAddress
             This can be used to determine the address of the RADIUS
             accounting server with which the client is communicating.
             This information could be useful in mounting an attack on
             the acounting server, which may contain sensitive financial
             data.

   radiusAccClientServerPortNumber This can be used to determine the
             port number on which the RADIUS accounting client is
             sending. This information could be useful in impersonating
             the client in order to send fraudulent data to the
             accounting server.

   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), 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 [12] and the View-based
   Access Control Model RFC 2575 [15] is recommended.  Using these
   security features, customer/users can give access to the objects only
   to those principals (users) that have legitimate rights to GET or SET
   (change/create/delete) them.

7.  Acknowledgments

   The authors acknowledge the contributions of the RADIUS Working Group
   in the development of this MIB.  Thanks to Narendra Gidwani of
   Microsoft, Allan C. Rubens of MERIT, Carl Rigney of Livingston and
   Peter Heitman of American Internet Corporation for useful discussions
   of this problem space.

8.  Authors' Addresses

   Bernard Aboba
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA 98052

   Phone: 425-936-6605
   EMail: bernarda@microsoft.com


   Glen Zorn
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA 98052

   Phone: 425-703-1559
   EMail: glennz@microsoft.com

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Acknowledgement

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