RFC2620
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.
Contents
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.
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.
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.
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.
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: [email protected]"
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
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.
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.
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.
Authors' Addresses
Bernard Aboba Microsoft Corporation One Microsoft Way Redmond, WA 98052
Phone: 425-936-6605 EMail: [email protected]
Glen Zorn Microsoft Corporation One Microsoft Way Redmond, WA 98052
Phone: 425-703-1559 EMail: [email protected]
Full Copyright Statement
Copyright (C) The Internet Society (1999). All Rights Reserved.
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