RADIUS Working Group Bernard Aboba
INTERNET-DRAFT Microsoft
Category: Informational Glen Zorn
<draft-ietf-radius-acc-clientmib-02.txt> Microsoft
11 November 1998
RADIUS Accounting Client MIB
1. Status of this Memo
This document is an Internet-Draft. Internet-Drafts are working docu-
ments of the Internet Engineering Task Force (IETF), its areas, and
its working groups. Note that other groups may also distribute work-
ing documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
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rial or to cite them other than as ``work in progress.''
To learn the current status of any Internet-Draft, please check the
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ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim).
The distribution of this memo is unlimited. It is filed as <draft-
ietf-radius-acc-clientmib-02.txt>, and expires May 1, 1999. Please
send comments to the authors.
2. Abstract
This memo defines a set of extensions which instrument RADIUS account-
ing client functions. These extensions represent a portion of the Man-
agement Information Base (MIB) for use with network management proto-
cols in the Internet community. Using these extensions IP-based man-
agement stations can manage RADIUS accounting clients.
3. 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 ser-
vices. As a result, the effective management of RADIUS accounting
clients is of considerable importance.
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4. The SNMP Management Framework
The SNMP Management Framework presently consists of five major compo-
nents:
o An overall architecture, described in RFC 2271 [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 1902 [5], RFC 1903
[6] and RFC 1904 [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 2272 [11]
and RFC 2274 [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 2273 [14]
and the view-based access control mechanism described in RFC
2275 [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 produced through the appropriate trans-
lations. 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 informa-
tion is not considered to change the semantics of the MIB.
5. 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 func-
tion, and thus would be expected to implement the RADIUS accounting
client MIB, while RADIUS accounting servers implement the server
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function, and thus woud be expected o 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.
5.1. 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.
6. Definitions
RADIUS-ACC-CLIENT-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE,
OBJECT-IDENTITY, experimental,
Counter32, Integer32, Gauge32,
IpAddress, TimeTicks FROM SNMPv2-SMI
DisplayString FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF;
radius OBJECT-IDENTITY
STATUS current
DESCRIPTION
"The OID assigned to RADIUS MIB work by the IANA."
::= { experimental 79 }
radiusAccounting OBJECT IDENTIFIER ::= {radius 2}
radiusAccClientMIB MODULE-IDENTITY
LAST-UPDATED "9811161659Z"
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
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"The MIB module for entities implementing the client side of
the Remote Access Dialin User Service (RADIUS) accounting
protocol."
::= { radiusAccounting 2 }
radiusAccClientMIBObjects OBJECT IDENTIFIER ::= { radiusAccClientMIB 1 }
radiusAccClient OBJECT IDENTIFIER ::= { radiusAccClientMIBObjects 1 }
radiusAccClientInvalidServerAddresses OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of RADIUS Accounting-Response packets
received from unknown addresses since client start-up."
::= { radiusAccClient 1 }
radiusAccClientIdentifier OBJECT-TYPE
SYNTAX DisplayString
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,
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radiusAccClientMalformedResponses Counter32,
radiusAccClientBadAuthenticators Counter32,
radiusAccClientPendingRequests Gauge32,
radiusAccClientTimeouts Counter32,
radiusAccClientUnknownTypes Counter32,
radiusAccClientPacketsDropped Counter32
}
radiusAccServerIndex OBJECT-TYPE
SYNTAX Integer32 (0..MAX)
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
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SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of RADIUS Accounting-Request packets
sent since client start-up. This does not include
retransmissions."
::= { radiusAccServerEntry 5 }
radiusAccClientRetransmissions OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of RADIUS Accounting-Request packets
retransmitted to this RADIUS accounting server since
client start-up. 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 total number of RADIUS packets received on the
accounting port from this server since client start-up."
::= { radiusAccServerEntry 7 }
radiusAccClientMalformedResponses OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of malformed RADIUS Accounting-Response
packets received from this server since client start-up.
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 total number of RADIUS Accounting-Response
packets which contained invalid authenticators
received from this server since client start-up."
::= { radiusAccServerEntry 9 }
radiusAccClientPendingRequests OBJECT-TYPE
SYNTAX Gauge32
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MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total 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 total number of accounting timeouts to ths server
since client startup. 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 total number of RADIUS packets of unknown type which
were received from this server on the accounting port
since client start-up."
::= { radiusAccServerEntry 12 }
radiusAccClientPacketsDropped OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of RADIUS packets which were received from
this server on the accounting port and dropped for some other
reason since client start-up."
::= { radiusAccServerEntry 13 }
-- conformance information
radiusAccClientMIBConformance
OBJECT IDENTIFIER ::= { radiusAccClientMIB 2 }
radiusAccClientMIBCompliances
OBJECT IDENTIFIER ::= { radiusAccClientMIBConformance 1 }
radiusAccClientMIBGroups
OBJECT IDENTIFIER ::= { radiusAccClientMIBConformance 2 }
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-- 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
7. References
[1] Harrington, D., Presuhn, R., and B. Wijnen, "An Architecture for
Describing SNMP Management Frameworks", RFC 2271, Cabletron Sys-
tems, Inc., BMC Software, Inc., IBM T. J. Watson Research, Jan-
uary 1998.
[2] Rose, M., and K. McCloghrie, "Structure and Identification of
Management Information for TCP/IP-based Internets", RFC 1155,
Performance Systems International, Hughes LAN Systems, May 1990.
[3] Rose, M., and K. McCloghrie, "Concise MIB Definitions", RFC 1212,
Performance Systems International, Hughes LAN Systems, March
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1991.
[4] M. Rose, "A Convention for Defining Traps for use with the SNMP",
RFC 1215, Performance Systems International, March 1991.
[5] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Structure
of Management Information for Version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC 1902, SNMP Research,Inc.,
Cisco Systems, Inc., Dover Beach Consulting, Inc., International
Network Services, January 1996.
[6] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Textual
Conventions for Version 2 of the Simple Network Management Proto-
col (SNMPv2)", RFC 1903, SNMP Research, Inc., Cisco Systems,
Inc., Dover Beach Consulting, Inc., International Network Ser-
vices, January 1996.
[7] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Confor-
mance Statements for Version 2 of the Simple Network Management
Protocol (SNMPv2)", RFC 1904, SNMP Research, Inc., Cisco Systems,
Inc., Dover Beach Consulting, Inc., International Network Ser-
vices, January 1996.
[8] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Net-
work Management Protocol", 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, "Introduc-
tion 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., Cisco Systems, Inc.,
Dover Beach Consulting, Inc., International Network Services,
January 1996.
[11] Case, J., Harrington D., Presuhn R., and B. Wijnen, "Message Pro-
cessing and Dispatching for the Simple Network Management Proto-
col (SNMP)", RFC 2272, SNMP Research, Inc., Cabletron Systems,
Inc., BMC Software, Inc., IBM T. J. Watson Research, January
1998.
[12] Blumenthal, U., and B. Wijnen, "User-based Security Model (USM)
for version 3 of the Simple Network Management Protocol
(SNMPv3)", RFC 2274, IBM T. J. Watson Research, January 1998.
[13] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Protocol
Operations for Version 2 of the Simple Network Management Proto-
col (SNMPv2)", RFC 1905, SNMP Research, Inc., Cisco Systems,
Inc., Dover Beach Consulting, Inc., International Network Ser-
vices, January 16.
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[14] Levi, D., Meyer, P., and B. Stewart, "SNMPv3 Applications", RFC
2273, SNMP Research, Inc., Secure Computing Corporation, Cisco
Systems, January 1998
[15] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based Access
Control Model (VACM) for the Simple Network Management Protocol
(SNMP)", RFC 2275, IBM T. J. Watson Research, BMC Software, Inc.,
Cisco Systems, Inc., January 1998
[16] Rigney, C., "RADIUS Accounting", RFC 2139, April 1997.
[17] "Information processing systems - Open Systems Interconnection -
Specification of Abstract Syntax Notation One (ASN.1)", Interna-
tional Organization for Standardization, International Standard
8824, December 1987.
8. 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 2274 [12] and the View-based Access
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Control Model RFC 2275 [15] is recommended. Using these security fea-
tures, 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.
9. Acknowledgments
Thanks to Narendra Gidwani of Microsoft, Allan C. Rubens of MERIT,
Carl Rigney of Livingston and Peter Heitman of American Internet Cor-
poration for useful discussions of this problemspace.
10. 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
11. Expiration Date
This memo is filed as <draft-ietf-radius-acc-clientmib-02.txt>, and
expires May 1, 1999.
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