RFC 2618

RADIUS Authentication Client MIB

πŸ“… published June 1999, from ietf

RFC 2618: RADIUS Authentication Client MIB πŸ’–

okay bestie, this is RFC 2618 and it's giving network management realness πŸŽ€. It's a Standards Track doc from June 1999, written by Bernard Aboba and Glenn Zorn, both at Microsoft ✨. The title block doesn't list anything it obsoletes or updates, so it's a standalone vibe πŸ¦‹.

Status of This Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. 🌸

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

Abstract πŸ“

This memo defines a set of extensions which instrument RADIUS authentication 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 authentication 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 authentication clients. πŸ’…

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

2. The SNMP Management Framework πŸ¦‹

okay so the SNMP Management Framework is made of five major components 😭:

  • An overall architecture, described in RFC 2571 [1].
  • 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 [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].
  • 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].
  • 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].
  • 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 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 πŸ’œ

The RADIUS authentication protocol, described in [16], distinguishes between the client function and the server function. In RADIUS authentication, clients send Access-Requests, and servers reply with Access-Accepts, Access-Rejects, and Access-Challenges. Typically NAS devices implement the client function, and thus would be expected to implement the RADIUS authentication client MIB, while RADIUS authentication servers implement the server function, and thus would be expected to implement the RADIUS authentication server MIB. πŸ‘‘

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

3.1. Selected objects πŸŽ€

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

  1. the RADIUS Authentication Server Table contains one row for each RADIUS authentication server that the client shares a secret with.

Each entry in the RADIUS Authentication Server Table includes fifteen columns presenting a view of the activity of the RADIUS authentication client. πŸ“


4. Definitions 🧚

Here's the MIB module itself, bestie. Get ready for the whole thing 😭✨:

RADIUS-AUTH-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;

radiusAuthClientMIB 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)
              authentication protocol."
       REVISION "9906110000Z"    -- 11 Jun 1999
       DESCRIPTION "Initial version as published in RFC 2618"
       ::= { radiusAuthentication 2 }

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

radiusAuthentication  OBJECT IDENTIFIER ::= {radiusMIB 1}

radiusAuthClientMIBObjects     OBJECT IDENTIFIER ::=
                                               { radiusAuthClientMIB 1 }

radiusAuthClient  OBJECT IDENTIFIER ::= { radiusAuthClientMIBObjects 1 }

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

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

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

radiusAuthServerEntry OBJECT-TYPE
      SYNTAX     RadiusAuthServerEntry
      MAX-ACCESS not-accessible
      STATUS     current
      DESCRIPTION
            "An entry (conceptual row) representing a RADIUS
             authentication server with which the client shares
             a secret."
      INDEX      { radiusAuthServerIndex }
      ::= { radiusAuthServerTable 1 }

RadiusAuthServerEntry ::= SEQUENCE {
      radiusAuthServerIndex                           Integer32,
      radiusAuthServerAddress                         IpAddress,
      radiusAuthClientServerPortNumber                Integer32,
      radiusAuthClientRoundTripTime                   TimeTicks,
      radiusAuthClientAccessRequests                  Counter32,
      radiusAuthClientAccessRetransmissions           Counter32,
      radiusAuthClientAccessAccepts                   Counter32,
      radiusAuthClientAccessRejects                   Counter32,
      radiusAuthClientAccessChallenges                Counter32,
      radiusAuthClientMalformedAccessResponses        Counter32,
      radiusAuthClientBadAuthenticators               Counter32,
      radiusAuthClientPendingRequests                   Gauge32,
      radiusAuthClientTimeouts                        Counter32,
      radiusAuthClientUnknownTypes                    Counter32,
      radiusAuthClientPacketsDropped                  Counter32
}

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

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

radiusAuthClientServerPortNumber  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."
      ::= { radiusAuthServerEntry 3 }

radiusAuthClientRoundTripTime  OBJECT-TYPE
      SYNTAX TimeTicks
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The time interval (in hundredths of a second) between
             the most recent Access-Reply/Access-Challenge and the
             Access-Request that matched it from this RADIUS
             authentication server."
      ::= { radiusAuthServerEntry 4 }

-- Request/Response statistics
--
-- TotalIncomingPackets = Accepts + Rejects + Challenges + UnknownTypes
--
-- TotalIncomingPackets - MalformedResponses - BadAuthenticators -
-- UnknownTypes - PacketsDropped = Successfully received
--
-- AccessRequests + PendingRequests + ClientTimeouts =
-- Successfully Received
--
--

radiusAuthClientAccessRequests OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Access-Request packets sent
             to this server. This does not include retransmissions."
      ::= { radiusAuthServerEntry 5 }

radiusAuthClientAccessRetransmissions OBJECT-TYPE

      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Access-Request packets
             retransmitted to this RADIUS authentication server."
      ::= { radiusAuthServerEntry 6 }

radiusAuthClientAccessAccepts OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Access-Accept packets
             (valid or invalid) received from this server."
      ::= { radiusAuthServerEntry 7 }

okay so the next batch of counters is all about the Access-Response family, and it's giving a whole lineup πŸŽ€

radiusAuthClientAccessRejects OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Access-Reject packets
             (valid or invalid) received from this server."
      ::= { radiusAuthServerEntry  8 }

radiusAuthClientAccessChallenges OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Access-Challenge packets
             (valid or invalid) received from this server."
      ::= { radiusAuthServerEntry 9 }

-- "Access-Response" includes an Access-Accept, Access-Challenge
-- or Access-Reject

radiusAuthClientMalformedAccessResponses OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of malformed RADIUS Access-Response
             packets received from this server.
             Malformed packets include packets with
             an invalid length. Bad authenticators or
             Signature attributes or unknown types are not
             included as malformed access responses."
      ::= { radiusAuthServerEntry 10 }

radiusAuthClientBadAuthenticators OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Access-Response packets
             containing invalid authenticators or Signature
             attributes received from this server."
      ::= { radiusAuthServerEntry 11 }

radiusAuthClientPendingRequests OBJECT-TYPE
      SYNTAX Gauge32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS Access-Request packets
             destined for this server that have not yet timed out
             or received a response. This variable is incremented
             when an Access-Request is sent and decremented due to
             receipt of an Acess-Accept, Access-Reject or
             Access-Challenge, a timeout or retransmission."
      ::= { radiusAuthServerEntry 12 }

radiusAuthClientTimeouts OBJECT-TYPE
     SYNTAX Counter32
     MAX-ACCESS read-only
     STATUS current
     DESCRIPTION
            "The number of authentication 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 a Request as well as a timeout."
      ::= { radiusAuthServerEntry  13 }

radiusAuthClientUnknownTypes 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 authentication port."
      ::= { radiusAuthServerEntry  14 }

radiusAuthClientPacketsDropped OBJECT-TYPE
      SYNTAX Counter32
      MAX-ACCESS read-only
      STATUS current
      DESCRIPTION
            "The number of RADIUS packets of which were
             received from this server on the authentication port
             and dropped for some other reason."
      ::= { radiusAuthServerEntry  15 }


-- conformance information

radiusAuthClientMIBConformance
             OBJECT IDENTIFIER ::= { radiusAuthClientMIB 2 }
radiusAuthClientMIBCompliances
             OBJECT IDENTIFIER ::= { radiusAuthClientMIBConformance 1 }
radiusAuthClientMIBGroups
             OBJECT IDENTIFIER ::= { radiusAuthClientMIBConformance 2 }


-- compliance statements

radiusAuthClientMIBCompliance MODULE-COMPLIANCE
     STATUS  current
     DESCRIPTION
           "The compliance statement for authentication clients
            implementing the RADIUS Authentication Client MIB."
     MODULE  -- this module
            MANDATORY-GROUPS { radiusAuthClientMIBGroup }

     ::= { radiusAuthClientMIBCompliances 1 }


-- units of conformance

radiusAuthClientMIBGroup OBJECT-GROUP
     OBJECTS { radiusAuthClientIdentifier,
               radiusAuthClientInvalidServerAddresses,
               radiusAuthServerAddress,
               radiusAuthClientServerPortNumber,
               radiusAuthClientRoundTripTime,
               radiusAuthClientAccessRequests,
               radiusAuthClientAccessRetransmissions,
               radiusAuthClientAccessAccepts,
               radiusAuthClientAccessRejects,
               radiusAuthClientAccessChallenges,
               radiusAuthClientMalformedAccessResponses,
               radiusAuthClientBadAuthenticators,
               radiusAuthClientPendingRequests,
               radiusAuthClientTimeouts,
               radiusAuthClientUnknownTypes,
               radiusAuthClientPacketsDropped
            }
     STATUS  current
     DESCRIPTION
           "The basic collection of objects providing management of
            RADIUS Authentication Clients."
     ::= { radiusAuthClientMIBGroups 1 }

END

5. References ✨

okay bestie, here are all the receipts πŸ“š

  • [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., Rubens, A., Simpson W. and S. Willens, "Remote Authentication Dial In User Service (RADIUS)", RFC 2138, April 1997.

6. Security Considerations πŸ”

this bit is super important, so read it carefully, bestie πŸ™ˆ

there are no management objects in this MIB with a MAX-ACCESS clause of read-write and/or read-create. so if this MIB is implemented correctly, an intruder can't alter or create any management objects of this MIB through direct SNMP SET operations πŸ”’

there are a few managed objects in this MIB that can hold sensitive information, and they're giving main character danger energy:

  • radiusAuthServerAddress: this can be used to determine the address of the RADIUS authentication server the client is talking to. that info could be useful for mounting an attack on the authentication server πŸ’€
  • radiusAuthClientServerPortNumber: this can be used to determine the port number the RADIUS authentication client is sending on. that info could be useful for impersonating the client in order to send data to the authentication server 😭

so it's really important to control even GET access to these objects, and maybe even encrypt their values when sending them over the network via SNMP. not every version of SNMP has features for a secure environment, so be careful 🫣

SNMPv1 by itself is not a secure environment. even if the network itself is secure (for example by using IPSec), there's no control over who on that secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB. literally anyone could be in the room πŸ‘€

it's recommended that implementers consider the security features provided by the SNMPv3 framework. specifically, the User-based Security Model in RFC 2574 [12] and the View-based Access Control Model in RFC 2575 [15] are recommended. with those features, customers and users can give access to these objects only to the principals (users) who have legitimate rights to GET or SET (change/create/delete) them 🧚

7. Acknowledgments 🫢

the authors gave a huge shoutout to the RADIUS Working Group for their contributions in developing this MIB πŸ’– thanks also to Narendra Gidwani of Microsoft, Allan C. Rubens of MERIT, Carl Rigney of Livingston and Peter Heitman of American Internet Corporation for the useful discussions about this problem space 🌸

8. Authors' Addresses πŸŽ€

these are the girls who made it happen ✨

Bernard Aboba
Microsoft Corporation
One Microsoft Wy
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

9. Intellectural Property Statement πŸ’…

okay so the IETF doesn't take a position on whether any intellectual property or other rights that might be claimed for the technology in this document are valid or what their scope is πŸ™…β€β™€οΈ it also doesn't say whether any license under those rights is or isn't available, and it hasn't claimed it made any effort to find out what rights exist. if you want the scoop on how the IETF handles rights for standards-track and standards-related documents, check out BCP-11. copies of rights claims that were submitted for publication, any assurances of licenses that will be available, or the outcome of an attempt to get a general license or permission for implementers or users to use those proprietary rights can all be obtained from the IETF Secretariat πŸ“¬

the IETF also invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that might cover technology required to practice this standard. send that info to the IETF Executive Director πŸ§šβ€β™€οΈ

okay bestie, the legal stuff at the end πŸ™ˆ but it's actually important, so let's go

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

You can copy this doc and share it with anyone, and you can make derivative works that comment on it, explain it, or help people implement it πŸ”₯. You can publish and distribute those, in whole or in part, with no restrictions of any kind, as long as the copyright notice and this paragraph are on every copy and derivative work. BUT the document itself can't be changed in any way. You can't remove the copyright notice or the references to the Internet Society or other Internet organizations. The exceptions are: changing it for developing Internet standards (then the copyright procedures in the Internet Standards process must be followed), or translating it into languages other than English 🌸

The permissions above are perpetual, and the Internet Society or its successors or assigns won't revoke them πŸ’œ

This document and the info in it is provided "AS IS", 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. πŸ’€

Acknowledgement 🫢

shoutout to the Internet Society πŸŽ€ Funding for the RFC Editor function is currently provided by them.

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