7 Network Working Group C. Rigney
8 Request for Comments: 2865 S. Willens
9 Obsoletes: 2138 Livingston
10 Category: Standards Track A. Rubens
17 Remote Authentication Dial In User Service (RADIUS)
21 This document specifies an Internet standards track protocol for the
22 Internet community, and requests discussion and suggestions for
23 improvements. Please refer to the current edition of the "Internet
24 Official Protocol Standards" (STD 1) for the standardization state
25 and status of this protocol. Distribution of this memo is unlimited.
29 Copyright (C) The Internet Society (2000). All Rights Reserved.
33 This protocol is widely implemented and used. Experience has shown
34 that it can suffer degraded performance and lost data when used in
35 large scale systems, in part because it does not include provisions
36 for congestion control. Readers of this document may find it
37 beneficial to track the progress of the IETF's AAA working group,
38 which may develop a successor protocol that better addresses the
39 scaling and congestion control issues.
43 This document describes a protocol for carrying authentication,
44 authorization, and configuration information between a Network Access
45 Server which desires to authenticate its links and a shared
46 Authentication Server.
50 This memo documents the RADIUS protocol. The early deployment of
51 RADIUS was done using UDP port number 1645, which conflicts with the
52 "datametrics" service. The officially assigned port number for
58 Rigney, et al. Standards Track [Page 1]
60 RFC 2865 RADIUS June 2000
65 1. Introduction .......................................... 3
66 1.1 Specification of Requirements ................... 4
67 1.2 Terminology ..................................... 5
68 2. Operation ............................................. 5
69 2.1 Challenge/Response .............................. 7
70 2.2 Interoperation with PAP and CHAP ................ 8
71 2.3 Proxy ........................................... 8
72 2.4 Why UDP? ........................................ 11
73 2.5 Retransmission Hints ............................ 12
74 2.6 Keep-Alives Considered Harmful .................. 13
75 3. Packet Format ......................................... 13
76 4. Packet Types .......................................... 17
77 4.1 Access-Request .................................. 17
78 4.2 Access-Accept ................................... 18
79 4.3 Access-Reject ................................... 20
80 4.4 Access-Challenge ................................ 21
81 5. Attributes ............................................ 22
82 5.1 User-Name ....................................... 26
83 5.2 User-Password ................................... 27
84 5.3 CHAP-Password ................................... 28
85 5.4 NAS-IP-Address .................................. 29
86 5.5 NAS-Port ........................................ 30
87 5.6 Service-Type .................................... 31
88 5.7 Framed-Protocol ................................. 33
89 5.8 Framed-IP-Address ............................... 34
90 5.9 Framed-IP-Netmask ............................... 34
91 5.10 Framed-Routing .................................. 35
92 5.11 Filter-Id ....................................... 36
93 5.12 Framed-MTU ...................................... 37
94 5.13 Framed-Compression .............................. 37
95 5.14 Login-IP-Host ................................... 38
96 5.15 Login-Service ................................... 39
97 5.16 Login-TCP-Port .................................. 40
98 5.17 (unassigned) .................................... 41
99 5.18 Reply-Message ................................... 41
100 5.19 Callback-Number ................................. 42
101 5.20 Callback-Id ..................................... 42
102 5.21 (unassigned) .................................... 43
103 5.22 Framed-Route .................................... 43
104 5.23 Framed-IPX-Network .............................. 44
105 5.24 State ........................................... 45
106 5.25 Class ........................................... 46
107 5.26 Vendor-Specific ................................. 47
108 5.27 Session-Timeout ................................. 48
109 5.28 Idle-Timeout .................................... 49
110 5.29 Termination-Action .............................. 49
114 Rigney, et al. Standards Track [Page 2]
116 RFC 2865 RADIUS June 2000
119 5.30 Called-Station-Id ............................... 50
120 5.31 Calling-Station-Id .............................. 51
121 5.32 NAS-Identifier .................................. 52
122 5.33 Proxy-State ..................................... 53
123 5.34 Login-LAT-Service ............................... 54
124 5.35 Login-LAT-Node .................................. 55
125 5.36 Login-LAT-Group ................................. 56
126 5.37 Framed-AppleTalk-Link ........................... 57
127 5.38 Framed-AppleTalk-Network ........................ 58
128 5.39 Framed-AppleTalk-Zone ........................... 58
129 5.40 CHAP-Challenge .................................. 59
130 5.41 NAS-Port-Type ................................... 60
131 5.42 Port-Limit ...................................... 61
132 5.43 Login-LAT-Port .................................. 62
133 5.44 Table of Attributes ............................. 63
134 6. IANA Considerations ................................... 64
135 6.1 Definition of Terms ............................. 64
136 6.2 Recommended Registration Policies ............... 65
137 7. Examples .............................................. 66
138 7.1 User Telnet to Specified Host ................... 66
139 7.2 Framed User Authenticating with CHAP ............ 67
140 7.3 User with Challenge-Response card ............... 68
141 8. Security Considerations ............................... 71
142 9. Change Log ............................................ 71
143 10. References ............................................ 73
144 11. Acknowledgements ...................................... 74
145 12. Chair's Address ....................................... 74
146 13. Authors' Addresses .................................... 75
147 14. Full Copyright Statement .............................. 76
151 This document obsoletes RFC 2138 [1]. A summary of the changes
152 between this document and RFC 2138 is available in the "Change Log"
155 Managing dispersed serial line and modem pools for large numbers of
156 users can create the need for significant administrative support.
157 Since modem pools are by definition a link to the outside world, they
158 require careful attention to security, authorization and accounting.
159 This can be best achieved by managing a single "database" of users,
160 which allows for authentication (verifying user name and password) as
161 well as configuration information detailing the type of service to
162 deliver to the user (for example, SLIP, PPP, telnet, rlogin).
170 Rigney, et al. Standards Track [Page 3]
172 RFC 2865 RADIUS June 2000
175 Key features of RADIUS are:
179 A Network Access Server (NAS) operates as a client of RADIUS. The
180 client is responsible for passing user information to designated
181 RADIUS servers, and then acting on the response which is returned.
183 RADIUS servers are responsible for receiving user connection
184 requests, authenticating the user, and then returning all
185 configuration information necessary for the client to deliver
188 A RADIUS server can act as a proxy client to other RADIUS servers
189 or other kinds of authentication servers.
193 Transactions between the client and RADIUS server are
194 authenticated through the use of a shared secret, which is never
195 sent over the network. In addition, any user passwords are sent
196 encrypted between the client and RADIUS server, to eliminate the
197 possibility that someone snooping on an unsecure network could
198 determine a user's password.
200 Flexible Authentication Mechanisms
202 The RADIUS server can support a variety of methods to authenticate
203 a user. When it is provided with the user name and original
204 password given by the user, it can support PPP PAP or CHAP, UNIX
205 login, and other authentication mechanisms.
209 All transactions are comprised of variable length Attribute-
210 Length-Value 3-tuples. New attribute values can be added without
211 disturbing existing implementations of the protocol.
213 1.1. Specification of Requirements
215 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
216 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
217 document are to be interpreted as described in BCP 14 [2]. These key
218 words mean the same thing whether capitalized or not.
220 An implementation is not compliant if it fails to satisfy one or more
221 of the must or must not requirements for the protocols it implements.
222 An implementation that satisfies all the must, must not, should and
226 Rigney, et al. Standards Track [Page 4]
228 RFC 2865 RADIUS June 2000
231 should not requirements for its protocols is said to be
232 "unconditionally compliant"; one that satisfies all the must and must
233 not requirements but not all the should or should not requirements
234 for its protocols is said to be "conditionally compliant".
236 A NAS that does not implement a given service MUST NOT implement the
237 RADIUS attributes for that service. For example, a NAS that is
238 unable to offer ARAP service MUST NOT implement the RADIUS attributes
239 for ARAP. A NAS MUST treat a RADIUS access-accept authorizing an
240 unavailable service as an access-reject instead.
244 This document frequently uses the following terms:
246 service The NAS provides a service to the dial-in user, such as PPP
249 session Each service provided by the NAS to a dial-in user
250 constitutes a session, with the beginning of the session
251 defined as the point where service is first provided and
252 the end of the session defined as the point where service
253 is ended. A user may have multiple sessions in parallel or
254 series if the NAS supports that.
257 This means the implementation discards the packet without
258 further processing. The implementation SHOULD provide the
259 capability of logging the error, including the contents of
260 the silently discarded packet, and SHOULD record the event
261 in a statistics counter.
265 When a client is configured to use RADIUS, any user of the client
266 presents authentication information to the client. This might be
267 with a customizable login prompt, where the user is expected to enter
268 their username and password. Alternatively, the user might use a
269 link framing protocol such as the Point-to-Point Protocol (PPP),
270 which has authentication packets which carry this information.
272 Once the client has obtained such information, it may choose to
273 authenticate using RADIUS. To do so, the client creates an "Access-
274 Request" containing such Attributes as the user's name, the user's
275 password, the ID of the client and the Port ID which the user is
276 accessing. When a password is present, it is hidden using a method
277 based on the RSA Message Digest Algorithm MD5 [3].
282 Rigney, et al. Standards Track [Page 5]
284 RFC 2865 RADIUS June 2000
287 The Access-Request is submitted to the RADIUS server via the network.
288 If no response is returned within a length of time, the request is
289 re-sent a number of times. The client can also forward requests to
290 an alternate server or servers in the event that the primary server
291 is down or unreachable. An alternate server can be used either after
292 a number of tries to the primary server fail, or in a round-robin
293 fashion. Retry and fallback algorithms are the topic of current
294 research and are not specified in detail in this document.
296 Once the RADIUS server receives the request, it validates the sending
297 client. A request from a client for which the RADIUS server does not
298 have a shared secret MUST be silently discarded. If the client is
299 valid, the RADIUS server consults a database of users to find the
300 user whose name matches the request. The user entry in the database
301 contains a list of requirements which must be met to allow access for
302 the user. This always includes verification of the password, but can
303 also specify the client(s) or port(s) to which the user is allowed
306 The RADIUS server MAY make requests of other servers in order to
307 satisfy the request, in which case it acts as a client.
309 If any Proxy-State attributes were present in the Access-Request,
310 they MUST be copied unmodified and in order into the response packet.
311 Other Attributes can be placed before, after, or even between the
312 Proxy-State attributes.
314 If any condition is not met, the RADIUS server sends an "Access-
315 Reject" response indicating that this user request is invalid. If
316 desired, the server MAY include a text message in the Access-Reject
317 which MAY be displayed by the client to the user. No other
318 Attributes (except Proxy-State) are permitted in an Access-Reject.
320 If all conditions are met and the RADIUS server wishes to issue a
321 challenge to which the user must respond, the RADIUS server sends an
322 "Access-Challenge" response. It MAY include a text message to be
323 displayed by the client to the user prompting for a response to the
324 challenge, and MAY include a State attribute.
326 If the client receives an Access-Challenge and supports
327 challenge/response it MAY display the text message, if any, to the
328 user, and then prompt the user for a response. The client then re-
329 submits its original Access-Request with a new request ID, with the
330 User-Password Attribute replaced by the response (encrypted), and
331 including the State Attribute from the Access-Challenge, if any.
332 Only 0 or 1 instances of the State Attribute SHOULD be
338 Rigney, et al. Standards Track [Page 6]
340 RFC 2865 RADIUS June 2000
343 present in a request. The server can respond to this new Access-
344 Request with either an Access-Accept, an Access-Reject, or another
347 If all conditions are met, the list of configuration values for the
348 user are placed into an "Access-Accept" response. These values
349 include the type of service (for example: SLIP, PPP, Login User) and
350 all necessary values to deliver the desired service. For SLIP and
351 PPP, this may include values such as IP address, subnet mask, MTU,
352 desired compression, and desired packet filter identifiers. For
353 character mode users, this may include values such as desired
356 2.1. Challenge/Response
358 In challenge/response authentication, the user is given an
359 unpredictable number and challenged to encrypt it and give back the
360 result. Authorized users are equipped with special devices such as
361 smart cards or software that facilitate calculation of the correct
362 response with ease. Unauthorized users, lacking the appropriate
363 device or software and lacking knowledge of the secret key necessary
364 to emulate such a device or software, can only guess at the response.
366 The Access-Challenge packet typically contains a Reply-Message
367 including a challenge to be displayed to the user, such as a numeric
368 value unlikely ever to be repeated. Typically this is obtained from
369 an external server that knows what type of authenticator is in the
370 possession of the authorized user and can therefore choose a random
371 or non-repeating pseudorandom number of an appropriate radix and
374 The user then enters the challenge into his device (or software) and
375 it calculates a response, which the user enters into the client which
376 forwards it to the RADIUS server via a second Access-Request. If the
377 response matches the expected response the RADIUS server replies with
378 an Access-Accept, otherwise an Access-Reject.
380 Example: The NAS sends an Access-Request packet to the RADIUS Server
381 with NAS-Identifier, NAS-Port, User-Name, User-Password (which may
382 just be a fixed string like "challenge" or ignored). The server
383 sends back an Access-Challenge packet with State and a Reply-Message
384 along the lines of "Challenge 12345678, enter your response at the
385 prompt" which the NAS displays. The NAS prompts for the response and
386 sends a NEW Access-Request to the server (with a new ID) with NAS-
387 Identifier, NAS-Port, User-Name, User-Password (the response just
388 entered by the user, encrypted), and the same State Attribute that
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396 RFC 2865 RADIUS June 2000
399 came with the Access-Challenge. The server then sends back either an
400 Access-Accept or Access-Reject based on whether the response matches
401 the required value, or it can even send another Access-Challenge.
403 2.2. Interoperation with PAP and CHAP
405 For PAP, the NAS takes the PAP ID and password and sends them in an
406 Access-Request packet as the User-Name and User-Password. The NAS MAY
407 include the Attributes Service-Type = Framed-User and Framed-Protocol
408 = PPP as a hint to the RADIUS server that PPP service is expected.
410 For CHAP, the NAS generates a random challenge (preferably 16 octets)
411 and sends it to the user, who returns a CHAP response along with a
412 CHAP ID and CHAP username. The NAS then sends an Access-Request
413 packet to the RADIUS server with the CHAP username as the User-Name
414 and with the CHAP ID and CHAP response as the CHAP-Password
415 (Attribute 3). The random challenge can either be included in the
416 CHAP-Challenge attribute or, if it is 16 octets long, it can be
417 placed in the Request Authenticator field of the Access-Request
418 packet. The NAS MAY include the Attributes Service-Type = Framed-
419 User and Framed-Protocol = PPP as a hint to the RADIUS server that
420 PPP service is expected.
422 The RADIUS server looks up a password based on the User-Name,
423 encrypts the challenge using MD5 on the CHAP ID octet, that password,
424 and the CHAP challenge (from the CHAP-Challenge attribute if present,
425 otherwise from the Request Authenticator), and compares that result
426 to the CHAP-Password. If they match, the server sends back an
427 Access-Accept, otherwise it sends back an Access-Reject.
429 If the RADIUS server is unable to perform the requested
430 authentication it MUST return an Access-Reject. For example, CHAP
431 requires that the user's password be available in cleartext to the
432 server so that it can encrypt the CHAP challenge and compare that to
433 the CHAP response. If the password is not available in cleartext to
434 the RADIUS server then the server MUST send an Access-Reject to the
439 With proxy RADIUS, one RADIUS server receives an authentication (or
440 accounting) request from a RADIUS client (such as a NAS), forwards
441 the request to a remote RADIUS server, receives the reply from the
442 remote server, and sends that reply to the client, possibly with
443 changes to reflect local administrative policy. A common use for
444 proxy RADIUS is roaming. Roaming permits two or more administrative
445 entities to allow each other's users to dial in to either entity's
450 Rigney, et al. Standards Track [Page 8]
452 RFC 2865 RADIUS June 2000
455 The NAS sends its RADIUS access-request to the "forwarding server"
456 which forwards it to the "remote server". The remote server sends a
457 response (Access-Accept, Access-Reject, or Access-Challenge) back to
458 the forwarding server, which sends it back to the NAS. The User-Name
459 attribute MAY contain a Network Access Identifier [8] for RADIUS
460 Proxy operations. The choice of which server receives the forwarded
461 request SHOULD be based on the authentication "realm". The
462 authentication realm MAY be the realm part of a Network Access
463 Identifier (a "named realm"). Alternatively, the choice of which
464 server receives the forwarded request MAY be based on whatever other
465 criteria the forwarding server is configured to use, such as Called-
466 Station-Id (a "numbered realm").
468 A RADIUS server can function as both a forwarding server and a remote
469 server, serving as a forwarding server for some realms and a remote
470 server for other realms. One forwarding server can act as a
471 forwarder for any number of remote servers. A remote server can have
472 any number of servers forwarding to it and can provide authentication
473 for any number of realms. One forwarding server can forward to
474 another forwarding server to create a chain of proxies, although care
475 must be taken to avoid introducing loops.
477 The following scenario illustrates a proxy RADIUS communication
478 between a NAS and the forwarding and remote RADIUS servers:
480 1. A NAS sends its access-request to the forwarding server.
482 2. The forwarding server forwards the access-request to the remote
485 3. The remote server sends an access-accept, access-reject or
486 access-challenge back to the forwarding server. For this example,
487 an access-accept is sent.
489 4. The forwarding server sends the access-accept to the NAS.
491 The forwarding server MUST treat any Proxy-State attributes already
492 in the packet as opaque data. Its operation MUST NOT depend on the
493 content of Proxy-State attributes added by previous servers.
495 If there are any Proxy-State attributes in the request received from
496 the client, the forwarding server MUST include those Proxy-State
497 attributes in its reply to the client. The forwarding server MAY
498 include the Proxy-State attributes in the access-request when it
499 forwards the request, or MAY omit them in the forwarded request. If
500 the forwarding server omits the Proxy-State attributes in the
501 forwarded access-request, it MUST attach them to the response before
502 sending it to the client.
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508 RFC 2865 RADIUS June 2000
511 We now examine each step in more detail.
513 1. A NAS sends its access-request to the forwarding server. The
514 forwarding server decrypts the User-Password, if present, using
515 the shared secret it knows for the NAS. If a CHAP-Password
516 attribute is present in the packet and no CHAP-Challenge attribute
517 is present, the forwarding server MUST leave the Request-
518 Authenticator untouched or copy it to a CHAP-Challenge attribute.
520 '' The forwarding server MAY add one Proxy-State attribute to the
521 packet. (It MUST NOT add more than one.) If it adds a Proxy-
522 State, the Proxy-State MUST appear after any other Proxy-States in
523 the packet. The forwarding server MUST NOT modify any other
524 Proxy-States that were in the packet (it may choose not to forward
525 them, but it MUST NOT change their contents). The forwarding
526 server MUST NOT change the order of any attributes of the same
527 type, including Proxy-State.
529 2. The forwarding server encrypts the User-Password, if present,
530 using the secret it shares with the remote server, sets the
531 Identifier as needed, and forwards the access-request to the
534 3. The remote server (if the final destination) verifies the user
535 using User-Password, CHAP-Password, or such method as future
536 extensions may dictate, and returns an access-accept, access-
537 reject or access-challenge back to the forwarding server. For
538 this example, an access-accept is sent. The remote server MUST
539 copy all Proxy-State attributes (and only the Proxy-State
540 attributes) in order from the access-request to the response
541 packet, without modifying them.
543 4. The forwarding server verifies the Response Authenticator using
544 the secret it shares with the remote server, and silently discards
545 the packet if it fails verification. If the packet passes
546 verification, the forwarding server removes the last Proxy-State
547 (if it attached one), signs the Response Authenticator using the
548 secret it shares with the NAS, restores the Identifier to match
549 the one in the original request by the NAS, and sends the access-
552 A forwarding server MAY need to modify attributes to enforce local
553 policy. Such policy is outside the scope of this document, with the
554 following restrictions. A forwarding server MUST not modify existing
555 Proxy-State, State, or Class attributes present in the packet.
562 Rigney, et al. Standards Track [Page 10]
564 RFC 2865 RADIUS June 2000
567 Implementers of forwarding servers should consider carefully which
568 values it is willing to accept for Service-Type. Careful
569 consideration must be given to the effects of passing along Service-
570 Types of NAS-Prompt or Administrative in a proxied Access-Accept, and
571 implementers may wish to provide mechanisms to block those or other
572 service types, or other attributes. Such mechanisms are outside the
573 scope of this document.
577 A frequently asked question is why RADIUS uses UDP instead of TCP as
578 a transport protocol. UDP was chosen for strictly technical reasons.
580 There are a number of issues which must be understood. RADIUS is a
581 transaction based protocol which has several interesting
584 1. If the request to a primary Authentication server fails, a
585 secondary server must be queried.
587 To meet this requirement, a copy of the request must be kept above
588 the transport layer to allow for alternate transmission. This
589 means that retransmission timers are still required.
591 2. The timing requirements of this particular protocol are
592 significantly different than TCP provides.
594 At one extreme, RADIUS does not require a "responsive" detection
595 of lost data. The user is willing to wait several seconds for the
596 authentication to complete. The generally aggressive TCP
597 retransmission (based on average round trip time) is not required,
598 nor is the acknowledgement overhead of TCP.
600 At the other extreme, the user is not willing to wait several
601 minutes for authentication. Therefore the reliable delivery of
602 TCP data two minutes later is not useful. The faster use of an
603 alternate server allows the user to gain access before giving up.
605 3. The stateless nature of this protocol simplifies the use of UDP.
607 Clients and servers come and go. Systems are rebooted, or are
608 power cycled independently. Generally this does not cause a
609 problem and with creative timeouts and detection of lost TCP
610 connections, code can be written to handle anomalous events. UDP
611 however completely eliminates any of this special handling. Each
612 client and server can open their UDP transport just once and leave
613 it open through all types of failure events on the network.
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620 RFC 2865 RADIUS June 2000
623 4. UDP simplifies the server implementation.
625 In the earliest implementations of RADIUS, the server was single
626 threaded. This means that a single request was received,
627 processed, and returned. This was found to be unmanageable in
628 environments where the back-end security mechanism took real time
629 (1 or more seconds). The server request queue would fill and in
630 environments where hundreds of people were being authenticated
631 every minute, the request turn-around time increased to longer
632 than users were willing to wait (this was especially severe when a
633 specific lookup in a database or over DNS took 30 or more
634 seconds). The obvious solution was to make the server multi-
635 threaded. Achieving this was simple with UDP. Separate processes
636 were spawned to serve each request and these processes could
637 respond directly to the client NAS with a simple UDP packet to the
638 original transport of the client.
640 It's not all a panacea. As noted, using UDP requires one thing which
641 is built into TCP: with UDP we must artificially manage
642 retransmission timers to the same server, although they don't require
643 the same attention to timing provided by TCP. This one penalty is a
644 small price to pay for the advantages of UDP in this protocol.
646 Without TCP we would still probably be using tin cans connected by
647 string. But for this particular protocol, UDP is a better choice.
649 2.5. Retransmission Hints
651 If the RADIUS server and alternate RADIUS server share the same
652 shared secret, it is OK to retransmit the packet to the alternate
653 RADIUS server with the same ID and Request Authenticator, because the
654 content of the attributes haven't changed. If you want to use a new
655 Request Authenticator when sending to the alternate server, you may.
657 If you change the contents of the User-Password attribute (or any
658 other attribute), you need a new Request Authenticator and therefore
661 If the NAS is retransmitting a RADIUS request to the same server as
662 before, and the attributes haven't changed, you MUST use the same
663 Request Authenticator, ID, and source port. If any attributes have
664 changed, you MUST use a new Request Authenticator and ID.
666 A NAS MAY use the same ID across all servers, or MAY keep track of
667 IDs separately for each server, it is up to the implementer. If a
668 NAS needs more than 256 IDs for outstanding requests, it MAY use
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676 RFC 2865 RADIUS June 2000
679 additional source ports to send requests from, and keep track of IDs
680 for each source port. This allows up to 16 million or so outstanding
681 requests at one time to a single server.
683 2.6. Keep-Alives Considered Harmful
685 Some implementers have adopted the practice of sending test RADIUS
686 requests to see if a server is alive. This practice is strongly
687 discouraged, since it adds to load and harms scalability without
688 providing any additional useful information. Since a RADIUS request
689 is contained in a single datagram, in the time it would take you to
690 send a ping you could just send the RADIUS request, and getting a
691 reply tells you that the RADIUS server is up. If you do not have a
692 RADIUS request to send, it does not matter if the server is up or
693 not, because you are not using it.
695 If you want to monitor your RADIUS server, use SNMP. That's what
700 Exactly one RADIUS packet is encapsulated in the UDP Data field [4],
701 where the UDP Destination Port field indicates 1812 (decimal).
703 When a reply is generated, the source and destination ports are
706 This memo documents the RADIUS protocol. The early deployment of
707 RADIUS was done using UDP port number 1645, which conflicts with the
708 "datametrics" service. The officially assigned port number for
730 Rigney, et al. Standards Track [Page 13]
732 RFC 2865 RADIUS June 2000
735 A summary of the RADIUS data format is shown below. The fields are
736 transmitted from left to right.
739 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
740 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
741 | Code | Identifier | Length |
742 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
747 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
749 +-+-+-+-+-+-+-+-+-+-+-+-+-
753 The Code field is one octet, and identifies the type of RADIUS
754 packet. When a packet is received with an invalid Code field, it
755 is silently discarded.
757 RADIUS Codes (decimal) are assigned as follows:
763 5 Accounting-Response
765 12 Status-Server (experimental)
766 13 Status-Client (experimental)
769 Codes 4 and 5 are covered in the RADIUS Accounting document [5].
770 Codes 12 and 13 are reserved for possible use, but are not further
775 The Identifier field is one octet, and aids in matching requests
776 and replies. The RADIUS server can detect a duplicate request if
777 it has the same client source IP address and source UDP port and
778 Identifier within a short span of time.
786 Rigney, et al. Standards Track [Page 14]
788 RFC 2865 RADIUS June 2000
793 The Length field is two octets. It indicates the length of the
794 packet including the Code, Identifier, Length, Authenticator and
795 Attribute fields. Octets outside the range of the Length field
796 MUST be treated as padding and ignored on reception. If the
797 packet is shorter than the Length field indicates, it MUST be
798 silently discarded. The minimum length is 20 and maximum length
803 The Authenticator field is sixteen (16) octets. The most
804 significant octet is transmitted first. This value is used to
805 authenticate the reply from the RADIUS server, and is used in the
806 password hiding algorithm.
808 Request Authenticator
810 In Access-Request Packets, the Authenticator value is a 16
811 octet random number, called the Request Authenticator. The
812 value SHOULD be unpredictable and unique over the lifetime of a
813 secret (the password shared between the client and the RADIUS
814 server), since repetition of a request value in conjunction
815 with the same secret would permit an attacker to reply with a
816 previously intercepted response. Since it is expected that the
817 same secret MAY be used to authenticate with servers in
818 disparate geographic regions, the Request Authenticator field
819 SHOULD exhibit global and temporal uniqueness.
821 The Request Authenticator value in an Access-Request packet
822 SHOULD also be unpredictable, lest an attacker trick a server
823 into responding to a predicted future request, and then use the
824 response to masquerade as that server to a future Access-
827 Although protocols such as RADIUS are incapable of protecting
828 against theft of an authenticated session via realtime active
829 wiretapping attacks, generation of unique unpredictable
830 requests can protect against a wide range of active attacks
831 against authentication.
833 The NAS and RADIUS server share a secret. That shared secret
834 followed by the Request Authenticator is put through a one-way
835 MD5 hash to create a 16 octet digest value which is xored with
836 the password entered by the user, and the xored result placed
842 Rigney, et al. Standards Track [Page 15]
844 RFC 2865 RADIUS June 2000
847 in the User-Password attribute in the Access-Request packet.
848 See the entry for User-Password in the section on Attributes
849 for a more detailed description.
851 Response Authenticator
853 The value of the Authenticator field in Access-Accept, Access-
854 Reject, and Access-Challenge packets is called the Response
855 Authenticator, and contains a one-way MD5 hash calculated over
856 a stream of octets consisting of: the RADIUS packet, beginning
857 with the Code field, including the Identifier, the Length, the
858 Request Authenticator field from the Access-Request packet, and
859 the response Attributes, followed by the shared secret. That
861 MD5(Code+ID+Length+RequestAuth+Attributes+Secret) where +
862 denotes concatenation.
866 The secret (password shared between the client and the RADIUS
867 server) SHOULD be at least as large and unguessable as a well-
868 chosen password. It is preferred that the secret be at least 16
869 octets. This is to ensure a sufficiently large range for the
870 secret to provide protection against exhaustive search attacks.
871 The secret MUST NOT be empty (length 0) since this would allow
872 packets to be trivially forged.
874 A RADIUS server MUST use the source IP address of the RADIUS UDP
875 packet to decide which shared secret to use, so that RADIUS
876 requests can be proxied.
878 When using a forwarding proxy, the proxy must be able to alter the
879 packet as it passes through in each direction - when the proxy
880 forwards the request, the proxy MAY add a Proxy-State Attribute,
881 and when the proxy forwards a response, it MUST remove its Proxy-
882 State Attribute if it added one. Proxy-State is always added or
883 removed after any other Proxy-States, but no other assumptions
884 regarding its location within the list of attributes can be made.
885 Since Access-Accept and Access-Reject replies are authenticated on
886 the entire packet contents, the stripping of the Proxy-State
887 attribute invalidates the signature in the packet - so the proxy
890 Further details of RADIUS proxy implementation are outside the
891 scope of this document.
898 Rigney, et al. Standards Track [Page 16]
900 RFC 2865 RADIUS June 2000
905 The RADIUS Packet type is determined by the Code field in the first
912 Access-Request packets are sent to a RADIUS server, and convey
913 information used to determine whether a user is allowed access to
914 a specific NAS, and any special services requested for that user.
915 An implementation wishing to authenticate a user MUST transmit a
916 RADIUS packet with the Code field set to 1 (Access-Request).
918 Upon receipt of an Access-Request from a valid client, an
919 appropriate reply MUST be transmitted.
921 An Access-Request SHOULD contain a User-Name attribute. It MUST
922 contain either a NAS-IP-Address attribute or a NAS-Identifier
925 An Access-Request MUST contain either a User-Password or a CHAP-
926 Password or a State. An Access-Request MUST NOT contain both a
927 User-Password and a CHAP-Password. If future extensions allow
928 other kinds of authentication information to be conveyed, the
929 attribute for that can be used in an Access-Request instead of
930 User-Password or CHAP-Password.
932 An Access-Request SHOULD contain a NAS-Port or NAS-Port-Type
933 attribute or both unless the type of access being requested does
934 not involve a port or the NAS does not distinguish among its
937 An Access-Request MAY contain additional attributes as a hint to
938 the server, but the server is not required to honor the hint.
940 When a User-Password is present, it is hidden using a method based
941 on the RSA Message Digest Algorithm MD5 [3].
954 Rigney, et al. Standards Track [Page 17]
956 RFC 2865 RADIUS June 2000
959 A summary of the Access-Request packet format is shown below. The
960 fields are transmitted from left to right.
963 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
964 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
965 | Code | Identifier | Length |
966 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
968 | Request Authenticator |
971 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
973 +-+-+-+-+-+-+-+-+-+-+-+-+-
977 1 for Access-Request.
981 The Identifier field MUST be changed whenever the content of the
982 Attributes field changes, and whenever a valid reply has been
983 received for a previous request. For retransmissions, the
984 Identifier MUST remain unchanged.
986 Request Authenticator
988 The Request Authenticator value MUST be changed each time a new
993 The Attribute field is variable in length, and contains the list
994 of Attributes that are required for the type of service, as well
995 as any desired optional Attributes.
1001 Access-Accept packets are sent by the RADIUS server, and provide
1002 specific configuration information necessary to begin delivery of
1003 service to the user. If all Attribute values received in an
1004 Access-Request are acceptable then the RADIUS implementation MUST
1005 transmit a packet with the Code field set to 2 (Access-Accept).
1010 Rigney, et al. Standards Track [Page 18]
1012 RFC 2865 RADIUS June 2000
1015 On reception of an Access-Accept, the Identifier field is matched
1016 with a pending Access-Request. The Response Authenticator field
1017 MUST contain the correct response for the pending Access-Request.
1018 Invalid packets are silently discarded.
1020 A summary of the Access-Accept packet format is shown below. The
1021 fields are transmitted from left to right.
1024 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1025 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1026 | Code | Identifier | Length |
1027 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1029 | Response Authenticator |
1032 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1034 +-+-+-+-+-+-+-+-+-+-+-+-+-
1038 2 for Access-Accept.
1042 The Identifier field is a copy of the Identifier field of the
1043 Access-Request which caused this Access-Accept.
1045 Response Authenticator
1047 The Response Authenticator value is calculated from the Access-
1048 Request value, as described earlier.
1052 The Attribute field is variable in length, and contains a list of
1053 zero or more Attributes.
1066 Rigney, et al. Standards Track [Page 19]
1068 RFC 2865 RADIUS June 2000
1075 If any value of the received Attributes is not acceptable, then
1076 the RADIUS server MUST transmit a packet with the Code field set
1077 to 3 (Access-Reject). It MAY include one or more Reply-Message
1078 Attributes with a text message which the NAS MAY display to the
1081 A summary of the Access-Reject packet format is shown below. The
1082 fields are transmitted from left to right.
1085 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1086 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1087 | Code | Identifier | Length |
1088 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1090 | Response Authenticator |
1093 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1095 +-+-+-+-+-+-+-+-+-+-+-+-+-
1099 3 for Access-Reject.
1103 The Identifier field is a copy of the Identifier field of the
1104 Access-Request which caused this Access-Reject.
1106 Response Authenticator
1108 The Response Authenticator value is calculated from the Access-
1109 Request value, as described earlier.
1113 The Attribute field is variable in length, and contains a list of
1114 zero or more Attributes.
1122 Rigney, et al. Standards Track [Page 20]
1124 RFC 2865 RADIUS June 2000
1127 4.4. Access-Challenge
1131 If the RADIUS server desires to send the user a challenge
1132 requiring a response, then the RADIUS server MUST respond to the
1133 Access-Request by transmitting a packet with the Code field set to
1134 11 (Access-Challenge).
1136 The Attributes field MAY have one or more Reply-Message
1137 Attributes, and MAY have a single State Attribute, or none.
1138 Vendor-Specific, Idle-Timeout, Session-Timeout and Proxy-State
1139 attributes MAY also be included. No other Attributes defined in
1140 this document are permitted in an Access-Challenge.
1142 On receipt of an Access-Challenge, the Identifier field is matched
1143 with a pending Access-Request. Additionally, the Response
1144 Authenticator field MUST contain the correct response for the
1145 pending Access-Request. Invalid packets are silently discarded.
1147 If the NAS does not support challenge/response, it MUST treat an
1148 Access-Challenge as though it had received an Access-Reject
1151 If the NAS supports challenge/response, receipt of a valid
1152 Access-Challenge indicates that a new Access-Request SHOULD be
1153 sent. The NAS MAY display the text message, if any, to the user,
1154 and then prompt the user for a response. It then sends its
1155 original Access-Request with a new request ID and Request
1156 Authenticator, with the User-Password Attribute replaced by the
1157 user's response (encrypted), and including the State Attribute
1158 from the Access-Challenge, if any. Only 0 or 1 instances of the
1159 State Attribute can be present in an Access-Request.
1161 A NAS which supports PAP MAY forward the Reply-Message to the
1162 dialing client and accept a PAP response which it can use as
1163 though the user had entered the response. If the NAS cannot do
1164 so, it MUST treat the Access-Challenge as though it had received
1165 an Access-Reject instead.
1178 Rigney, et al. Standards Track [Page 21]
1180 RFC 2865 RADIUS June 2000
1183 A summary of the Access-Challenge packet format is shown below. The
1184 fields are transmitted from left to right.
1187 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1188 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1189 | Code | Identifier | Length |
1190 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1192 | Response Authenticator |
1195 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1197 +-+-+-+-+-+-+-+-+-+-+-+-+-
1201 11 for Access-Challenge.
1205 The Identifier field is a copy of the Identifier field of the
1206 Access-Request which caused this Access-Challenge.
1208 Response Authenticator
1210 The Response Authenticator value is calculated from the Access-
1211 Request value, as described earlier.
1215 The Attributes field is variable in length, and contains a list of
1216 zero or more Attributes.
1220 RADIUS Attributes carry the specific authentication, authorization,
1221 information and configuration details for the request and reply.
1223 The end of the list of Attributes is indicated by the Length of the
1226 Some Attributes MAY be included more than once. The effect of this
1227 is Attribute specific, and is specified in each Attribute
1228 description. A summary table is provided at the end of the
1229 "Attributes" section.
1234 Rigney, et al. Standards Track [Page 22]
1236 RFC 2865 RADIUS June 2000
1239 If multiple Attributes with the same Type are present, the order of
1240 Attributes with the same Type MUST be preserved by any proxies. The
1241 order of Attributes of different Types is not required to be
1242 preserved. A RADIUS server or client MUST NOT have any dependencies
1243 on the order of attributes of different types. A RADIUS server or
1244 client MUST NOT require attributes of the same type to be contiguous.
1246 Where an Attribute's description limits which kinds of packet it can
1247 be contained in, this applies only to the packet types defined in
1248 this document, namely Access-Request, Access-Accept, Access-Reject
1249 and Access-Challenge (Codes 1, 2, 3, and 11). Other documents
1250 defining other packet types may also use Attributes described here.
1251 To determine which Attributes are allowed in Accounting-Request and
1252 Accounting-Response packets (Codes 4 and 5) refer to the RADIUS
1253 Accounting document [5].
1255 Likewise where packet types defined here state that only certain
1256 Attributes are permissible in them, future memos defining new
1257 Attributes should indicate which packet types the new Attributes may
1260 A summary of the Attribute format is shown below. The fields are
1261 transmitted from left to right.
1264 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0
1265 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
1266 | Type | Length | Value ...
1267 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
1271 The Type field is one octet. Up-to-date values of the RADIUS Type
1272 field are specified in the most recent "Assigned Numbers" RFC [6].
1273 Values 192-223 are reserved for experimental use, values 224-240
1274 are reserved for implementation-specific use, and values 241-255
1275 are reserved and should not be used.
1277 A RADIUS server MAY ignore Attributes with an unknown Type.
1279 A RADIUS client MAY ignore Attributes with an unknown Type.
1290 Rigney, et al. Standards Track [Page 23]
1292 RFC 2865 RADIUS June 2000
1295 This specification concerns the following values:
1309 13 Framed-Compression
1319 23 Framed-IPX-Network
1325 29 Termination-Action
1326 30 Called-Station-Id
1327 31 Calling-Station-Id
1330 34 Login-LAT-Service
1333 37 Framed-AppleTalk-Link
1334 38 Framed-AppleTalk-Network
1335 39 Framed-AppleTalk-Zone
1336 40-59 (reserved for accounting)
1346 Rigney, et al. Standards Track [Page 24]
1348 RFC 2865 RADIUS June 2000
1353 The Length field is one octet, and indicates the length of this
1354 Attribute including the Type, Length and Value fields. If an
1355 Attribute is received in an Access-Request but with an invalid
1356 Length, an Access-Reject SHOULD be transmitted. If an Attribute
1357 is received in an Access-Accept, Access-Reject or Access-Challenge
1358 packet with an invalid length, the packet MUST either be treated
1359 as an Access-Reject or else silently discarded.
1363 The Value field is zero or more octets and contains information
1364 specific to the Attribute. The format and length of the Value
1365 field is determined by the Type and Length fields.
1367 Note that none of the types in RADIUS terminate with a NUL (hex
1368 00). In particular, types "text" and "string" in RADIUS do not
1369 terminate with a NUL (hex 00). The Attribute has a length field
1370 and does not use a terminator. Text contains UTF-8 encoded 10646
1371 [7] characters and String contains 8-bit binary data. Servers and
1372 servers and clients MUST be able to deal with embedded nulls.
1373 RADIUS implementers using C are cautioned not to use strcpy() when
1376 The format of the value field is one of five data types. Note
1377 that type "text" is a subset of type "string".
1379 text 1-253 octets containing UTF-8 encoded 10646 [7]
1380 characters. Text of length zero (0) MUST NOT be sent;
1381 omit the entire attribute instead.
1383 string 1-253 octets containing binary data (values 0 through
1384 255 decimal, inclusive). Strings of length zero (0)
1385 MUST NOT be sent; omit the entire attribute instead.
1387 address 32 bit value, most significant octet first.
1389 integer 32 bit unsigned value, most significant octet first.
1391 time 32 bit unsigned value, most significant octet first --
1392 seconds since 00:00:00 UTC, January 1, 1970. The
1393 standard Attributes do not use this data type but it is
1394 presented here for possible use in future attributes.
1402 Rigney, et al. Standards Track [Page 25]
1404 RFC 2865 RADIUS June 2000
1411 This Attribute indicates the name of the user to be authenticated.
1412 It MUST be sent in Access-Request packets if available.
1414 It MAY be sent in an Access-Accept packet, in which case the
1415 client SHOULD use the name returned in the Access-Accept packet in
1416 all Accounting-Request packets for this session. If the Access-
1417 Accept includes Service-Type = Rlogin and the User-Name attribute,
1418 a NAS MAY use the returned User-Name when performing the Rlogin
1421 A summary of the User-Name Attribute format is shown below. The
1422 fields are transmitted from left to right.
1425 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1426 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
1427 | Type | Length | String ...
1428 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
1440 The String field is one or more octets. The NAS may limit the
1441 maximum length of the User-Name but the ability to handle at least
1442 63 octets is recommended.
1444 The format of the username MAY be one of several forms:
1446 text Consisting only of UTF-8 encoded 10646 [7] characters.
1448 network access identifier
1449 A Network Access Identifier as described in RFC 2486
1453 A name in ASN.1 form used in Public Key authentication
1458 Rigney, et al. Standards Track [Page 26]
1460 RFC 2865 RADIUS June 2000
1467 This Attribute indicates the password of the user to be
1468 authenticated, or the user's input following an Access-Challenge.
1469 It is only used in Access-Request packets.
1471 On transmission, the password is hidden. The password is first
1472 padded at the end with nulls to a multiple of 16 octets. A one-
1473 way MD5 hash is calculated over a stream of octets consisting of
1474 the shared secret followed by the Request Authenticator. This
1475 value is XORed with the first 16 octet segment of the password and
1476 placed in the first 16 octets of the String field of the User-
1479 If the password is longer than 16 characters, a second one-way MD5
1480 hash is calculated over a stream of octets consisting of the
1481 shared secret followed by the result of the first xor. That hash
1482 is XORed with the second 16 octet segment of the password and
1483 placed in the second 16 octets of the String field of the User-
1486 If necessary, this operation is repeated, with each xor result
1487 being used along with the shared secret to generate the next hash
1488 to xor the next segment of the password, to no more than 128
1491 The method is taken from the book "Network Security" by Kaufman,
1492 Perlman and Speciner [9] pages 109-110. A more precise
1493 explanation of the method follows:
1495 Call the shared secret S and the pseudo-random 128-bit Request
1496 Authenticator RA. Break the password into 16-octet chunks p1, p2,
1497 etc. with the last one padded at the end with nulls to a 16-octet
1498 boundary. Call the ciphertext blocks c(1), c(2), etc. We'll need
1499 intermediate values b1, b2, etc.
1501 b1 = MD5(S + RA) c(1) = p1 xor b1
1502 b2 = MD5(S + c(1)) c(2) = p2 xor b2
1506 bi = MD5(S + c(i-1)) c(i) = pi xor bi
1508 The String will contain c(1)+c(2)+...+c(i) where + denotes
1514 Rigney, et al. Standards Track [Page 27]
1516 RFC 2865 RADIUS June 2000
1519 On receipt, the process is reversed to yield the original
1522 A summary of the User-Password Attribute format is shown below. The
1523 fields are transmitted from left to right.
1526 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1527 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
1528 | Type | Length | String ...
1529 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
1533 2 for User-Password.
1537 At least 18 and no larger than 130.
1541 The String field is between 16 and 128 octets long, inclusive.
1547 This Attribute indicates the response value provided by a PPP
1548 Challenge-Handshake Authentication Protocol (CHAP) user in
1549 response to the challenge. It is only used in Access-Request
1552 The CHAP challenge value is found in the CHAP-Challenge Attribute
1553 (60) if present in the packet, otherwise in the Request
1554 Authenticator field.
1556 A summary of the CHAP-Password Attribute format is shown below. The
1557 fields are transmitted from left to right.
1560 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9
1561 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
1562 | Type | Length | CHAP Ident | String ...
1563 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
1570 Rigney, et al. Standards Track [Page 28]
1572 RFC 2865 RADIUS June 2000
1577 3 for CHAP-Password.
1585 This field is one octet, and contains the CHAP Identifier from the
1586 user's CHAP Response.
1590 The String field is 16 octets, and contains the CHAP Response from
1597 This Attribute indicates the identifying IP Address of the NAS
1598 which is requesting authentication of the user, and SHOULD be
1599 unique to the NAS within the scope of the RADIUS server. NAS-IP-
1600 Address is only used in Access-Request packets. Either NAS-IP-
1601 Address or NAS-Identifier MUST be present in an Access-Request
1604 Note that NAS-IP-Address MUST NOT be used to select the shared
1605 secret used to authenticate the request. The source IP address of
1606 the Access-Request packet MUST be used to select the shared
1609 A summary of the NAS-IP-Address Attribute format is shown below. The
1610 fields are transmitted from left to right.
1613 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1614 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1615 | Type | Length | Address
1616 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1618 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1622 4 for NAS-IP-Address.
1626 Rigney, et al. Standards Track [Page 29]
1628 RFC 2865 RADIUS June 2000
1637 The Address field is four octets.
1643 This Attribute indicates the physical port number of the NAS which
1644 is authenticating the user. It is only used in Access-Request
1645 packets. Note that this is using "port" in its sense of a
1646 physical connection on the NAS, not in the sense of a TCP or UDP
1647 port number. Either NAS-Port or NAS-Port-Type (61) or both SHOULD
1648 be present in an Access-Request packet, if the NAS differentiates
1651 A summary of the NAS-Port Attribute format is shown below. The
1652 fields are transmitted from left to right.
1655 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1656 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1657 | Type | Length | Value
1658 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1660 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1672 The Value field is four octets.
1682 Rigney, et al. Standards Track [Page 30]
1684 RFC 2865 RADIUS June 2000
1691 This Attribute indicates the type of service the user has
1692 requested, or the type of service to be provided. It MAY be used
1693 in both Access-Request and Access-Accept packets. A NAS is not
1694 required to implement all of these service types, and MUST treat
1695 unknown or unsupported Service-Types as though an Access-Reject
1696 had been received instead.
1698 A summary of the Service-Type Attribute format is shown below. The
1699 fields are transmitted from left to right.
1702 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1703 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1704 | Type | Length | Value
1705 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1707 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1719 The Value field is four octets.
1729 9 Callback NAS Prompt
1731 11 Callback Administrative
1738 Rigney, et al. Standards Track [Page 31]
1740 RFC 2865 RADIUS June 2000
1743 The service types are defined as follows when used in an Access-
1744 Accept. When used in an Access-Request, they MAY be considered to
1745 be a hint to the RADIUS server that the NAS has reason to believe
1746 the user would prefer the kind of service indicated, but the
1747 server is not required to honor the hint.
1749 Login The user should be connected to a host.
1751 Framed A Framed Protocol should be started for the
1752 User, such as PPP or SLIP.
1754 Callback Login The user should be disconnected and called
1755 back, then connected to a host.
1757 Callback Framed The user should be disconnected and called
1758 back, then a Framed Protocol should be started
1759 for the User, such as PPP or SLIP.
1761 Outbound The user should be granted access to outgoing
1764 Administrative The user should be granted access to the
1765 administrative interface to the NAS from which
1766 privileged commands can be executed.
1768 NAS Prompt The user should be provided a command prompt
1769 on the NAS from which non-privileged commands
1772 Authenticate Only Only Authentication is requested, and no
1773 authorization information needs to be returned
1774 in the Access-Accept (typically used by proxy
1775 servers rather than the NAS itself).
1777 Callback NAS Prompt The user should be disconnected and called
1778 back, then provided a command prompt on the
1779 NAS from which non-privileged commands can be
1782 Call Check Used by the NAS in an Access-Request packet to
1783 indicate that a call is being received and
1784 that the RADIUS server should send back an
1785 Access-Accept to answer the call, or an
1786 Access-Reject to not accept the call,
1787 typically based on the Called-Station-Id or
1788 Calling-Station-Id attributes. It is
1794 Rigney, et al. Standards Track [Page 32]
1796 RFC 2865 RADIUS June 2000
1799 recommended that such Access-Requests use the
1800 value of Calling-Station-Id as the value of
1803 Callback Administrative
1804 The user should be disconnected and called
1805 back, then granted access to the
1806 administrative interface to the NAS from which
1807 privileged commands can be executed.
1809 5.7. Framed-Protocol
1813 This Attribute indicates the framing to be used for framed access.
1814 It MAY be used in both Access-Request and Access-Accept packets.
1816 A summary of the Framed-Protocol Attribute format is shown below.
1817 The fields are transmitted from left to right.
1820 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1821 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1822 | Type | Length | Value
1823 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1825 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1829 7 for Framed-Protocol.
1837 The Value field is four octets.
1841 3 AppleTalk Remote Access Protocol (ARAP)
1842 4 Gandalf proprietary SingleLink/MultiLink protocol
1843 5 Xylogics proprietary IPX/SLIP
1850 Rigney, et al. Standards Track [Page 33]
1852 RFC 2865 RADIUS June 2000
1855 5.8. Framed-IP-Address
1859 This Attribute indicates the address to be configured for the
1860 user. It MAY be used in Access-Accept packets. It MAY be used in
1861 an Access-Request packet as a hint by the NAS to the server that
1862 it would prefer that address, but the server is not required to
1865 A summary of the Framed-IP-Address Attribute format is shown below.
1866 The fields are transmitted from left to right.
1869 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1870 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1871 | Type | Length | Address
1872 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1874 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1878 8 for Framed-IP-Address.
1886 The Address field is four octets. The value 0xFFFFFFFF indicates
1887 that the NAS Should allow the user to select an address (e.g.
1888 Negotiated). The value 0xFFFFFFFE indicates that the NAS should
1889 select an address for the user (e.g. Assigned from a pool of
1890 addresses kept by the NAS). Other valid values indicate that the
1891 NAS should use that value as the user's IP address.
1893 5.9. Framed-IP-Netmask
1897 This Attribute indicates the IP netmask to be configured for the
1898 user when the user is a router to a network. It MAY be used in
1899 Access-Accept packets. It MAY be used in an Access-Request packet
1900 as a hint by the NAS to the server that it would prefer that
1901 netmask, but the server is not required to honor the hint.
1906 Rigney, et al. Standards Track [Page 34]
1908 RFC 2865 RADIUS June 2000
1911 A summary of the Framed-IP-Netmask Attribute format is shown below.
1912 The fields are transmitted from left to right.
1915 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1916 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1917 | Type | Length | Address
1918 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1920 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1924 9 for Framed-IP-Netmask.
1932 The Address field is four octets specifying the IP netmask of the
1935 5.10. Framed-Routing
1939 This Attribute indicates the routing method for the user, when the
1940 user is a router to a network. It is only used in Access-Accept
1943 A summary of the Framed-Routing Attribute format is shown below. The
1944 fields are transmitted from left to right.
1947 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1948 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1949 | Type | Length | Value
1950 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1952 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1956 10 for Framed-Routing.
1962 Rigney, et al. Standards Track [Page 35]
1964 RFC 2865 RADIUS June 2000
1973 The Value field is four octets.
1976 1 Send routing packets
1977 2 Listen for routing packets
1984 This Attribute indicates the name of the filter list for this
1985 user. Zero or more Filter-Id attributes MAY be sent in an
1986 Access-Accept packet.
1988 Identifying a filter list by name allows the filter to be used on
1989 different NASes without regard to filter-list implementation
1992 A summary of the Filter-Id Attribute format is shown below. The
1993 fields are transmitted from left to right.
1996 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1997 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
1998 | Type | Length | Text ...
1999 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2011 The Text field is one or more octets, and its contents are
2012 implementation dependent. It is intended to be human readable and
2013 MUST NOT affect operation of the protocol. It is recommended that
2014 the message contain UTF-8 encoded 10646 [7] characters.
2018 Rigney, et al. Standards Track [Page 36]
2020 RFC 2865 RADIUS June 2000
2027 This Attribute indicates the Maximum Transmission Unit to be
2028 configured for the user, when it is not negotiated by some other
2029 means (such as PPP). It MAY be used in Access-Accept packets. It
2030 MAY be used in an Access-Request packet as a hint by the NAS to
2031 the server that it would prefer that value, but the server is not
2032 required to honor the hint.
2034 A summary of the Framed-MTU Attribute format is shown below. The
2035 fields are transmitted from left to right.
2038 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2039 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2040 | Type | Length | Value
2041 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2043 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2055 The Value field is four octets. Despite the size of the field,
2056 values range from 64 to 65535.
2058 5.13. Framed-Compression
2062 This Attribute indicates a compression protocol to be used for the
2063 link. It MAY be used in Access-Accept packets. It MAY be used in
2064 an Access-Request packet as a hint to the server that the NAS
2065 would prefer to use that compression, but the server is not
2066 required to honor the hint.
2068 More than one compression protocol Attribute MAY be sent. It is
2069 the responsibility of the NAS to apply the proper compression
2070 protocol to appropriate link traffic.
2074 Rigney, et al. Standards Track [Page 37]
2076 RFC 2865 RADIUS June 2000
2079 A summary of the Framed-Compression Attribute format is shown below.
2080 The fields are transmitted from left to right.
2083 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2084 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2085 | Type | Length | Value
2086 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2088 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2092 13 for Framed-Compression.
2100 The Value field is four octets.
2103 1 VJ TCP/IP header compression [10]
2104 2 IPX header compression
2105 3 Stac-LZS compression
2111 This Attribute indicates the system with which to connect the user,
2112 when the Login-Service Attribute is included. It MAY be used in
2113 Access-Accept packets. It MAY be used in an Access-Request packet as
2114 a hint to the server that the NAS would prefer to use that host, but
2115 the server is not required to honor the hint.
2117 A summary of the Login-IP-Host Attribute format is shown below. The
2118 fields are transmitted from left to right.
2130 Rigney, et al. Standards Track [Page 38]
2132 RFC 2865 RADIUS June 2000
2136 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2137 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2138 | Type | Length | Address
2139 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2141 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2145 14 for Login-IP-Host.
2153 The Address field is four octets. The value 0xFFFFFFFF indicates
2154 that the NAS SHOULD allow the user to select an address. The
2155 value 0 indicates that the NAS SHOULD select a host to connect the
2156 user to. Other values indicate the address the NAS SHOULD connect
2163 This Attribute indicates the service to use to connect the user to
2164 the login host. It is only used in Access-Accept packets.
2166 A summary of the Login-Service Attribute format is shown below. The
2167 fields are transmitted from left to right.
2170 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2171 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2172 | Type | Length | Value
2173 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2175 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2179 15 for Login-Service.
2186 Rigney, et al. Standards Track [Page 39]
2188 RFC 2865 RADIUS June 2000
2197 The Value field is four octets.
2202 3 PortMaster (proprietary)
2206 8 TCP Clear Quiet (suppresses any NAS-generated connect string)
2208 5.16. Login-TCP-Port
2212 This Attribute indicates the TCP port with which the user is to be
2213 connected, when the Login-Service Attribute is also present. It
2214 is only used in Access-Accept packets.
2216 A summary of the Login-TCP-Port Attribute format is shown below. The
2217 fields are transmitted from left to right.
2220 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2221 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2222 | Type | Length | Value
2223 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2225 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2229 16 for Login-TCP-Port.
2237 The Value field is four octets. Despite the size of the field,
2238 values range from 0 to 65535.
2242 Rigney, et al. Standards Track [Page 40]
2244 RFC 2865 RADIUS June 2000
2251 ATTRIBUTE TYPE 17 HAS NOT BEEN ASSIGNED.
2257 This Attribute indicates text which MAY be displayed to the user.
2259 When used in an Access-Accept, it is the success message.
2261 When used in an Access-Reject, it is the failure message. It MAY
2262 indicate a dialog message to prompt the user before another
2263 Access-Request attempt.
2265 When used in an Access-Challenge, it MAY indicate a dialog message
2266 to prompt the user for a response.
2268 Multiple Reply-Message's MAY be included and if any are displayed,
2269 they MUST be displayed in the same order as they appear in the
2272 A summary of the Reply-Message Attribute format is shown below. The
2273 fields are transmitted from left to right.
2276 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2277 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2278 | Type | Length | Text ...
2279 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2283 18 for Reply-Message.
2291 The Text field is one or more octets, and its contents are
2292 implementation dependent. It is intended to be human readable,
2293 and MUST NOT affect operation of the protocol. It is recommended
2294 that the message contain UTF-8 encoded 10646 [7] characters.
2298 Rigney, et al. Standards Track [Page 41]
2300 RFC 2865 RADIUS June 2000
2303 5.19. Callback-Number
2307 This Attribute indicates a dialing string to be used for callback.
2308 It MAY be used in Access-Accept packets. It MAY be used in an
2309 Access-Request packet as a hint to the server that a Callback
2310 service is desired, but the server is not required to honor the
2313 A summary of the Callback-Number Attribute format is shown below.
2314 The fields are transmitted from left to right.
2317 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2318 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2319 | Type | Length | String ...
2320 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2324 19 for Callback-Number.
2332 The String field is one or more octets. The actual format of the
2333 information is site or application specific, and a robust
2334 implementation SHOULD support the field as undistinguished octets.
2336 The codification of the range of allowed usage of this field is
2337 outside the scope of this specification.
2343 This Attribute indicates the name of a place to be called, to be
2344 interpreted by the NAS. It MAY be used in Access-Accept packets.
2354 Rigney, et al. Standards Track [Page 42]
2356 RFC 2865 RADIUS June 2000
2359 A summary of the Callback-Id Attribute format is shown below. The
2360 fields are transmitted from left to right.
2363 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2364 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2365 | Type | Length | String ...
2366 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2378 The String field is one or more octets. The actual format of the
2379 information is site or application specific, and a robust
2380 implementation SHOULD support the field as undistinguished octets.
2382 The codification of the range of allowed usage of this field is
2383 outside the scope of this specification.
2389 ATTRIBUTE TYPE 21 HAS NOT BEEN ASSIGNED.
2395 This Attribute provides routing information to be configured for
2396 the user on the NAS. It is used in the Access-Accept packet and
2397 can appear multiple times.
2399 A summary of the Framed-Route Attribute format is shown below. The
2400 fields are transmitted from left to right.
2403 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
2404 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2405 | Type | Length | Text ...
2406 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2410 Rigney, et al. Standards Track [Page 43]
2412 RFC 2865 RADIUS June 2000
2417 22 for Framed-Route.
2425 The Text field is one or more octets, and its contents are
2426 implementation dependent. It is intended to be human readable and
2427 MUST NOT affect operation of the protocol. It is recommended that
2428 the message contain UTF-8 encoded 10646 [7] characters.
2430 For IP routes, it SHOULD contain a destination prefix in dotted
2431 quad form optionally followed by a slash and a decimal length
2432 specifier stating how many high order bits of the prefix to use.
2433 That is followed by a space, a gateway address in dotted quad
2434 form, a space, and one or more metrics separated by spaces. For
2435 example, "192.168.1.0/24 192.168.1.1 1 2 -1 3 400". The length
2436 specifier may be omitted, in which case it defaults to 8 bits for
2437 class A prefixes, 16 bits for class B prefixes, and 24 bits for
2438 class C prefixes. For example, "192.168.1.0 192.168.1.1 1".
2440 Whenever the gateway address is specified as "0.0.0.0" the IP
2441 address of the user SHOULD be used as the gateway address.
2443 5.23. Framed-IPX-Network
2447 This Attribute indicates the IPX Network number to be configured
2448 for the user. It is used in Access-Accept packets.
2450 A summary of the Framed-IPX-Network Attribute format is shown below.
2451 The fields are transmitted from left to right.
2454 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2455 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2456 | Type | Length | Value
2457 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2459 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2466 Rigney, et al. Standards Track [Page 44]
2468 RFC 2865 RADIUS June 2000
2473 23 for Framed-IPX-Network.
2481 The Value field is four octets. The value 0xFFFFFFFE indicates
2482 that the NAS should select an IPX network for the user (e.g.
2483 assigned from a pool of one or more IPX networks kept by the NAS).
2484 Other values should be used as the IPX network for the link to the
2491 This Attribute is available to be sent by the server to the client
2492 in an Access-Challenge and MUST be sent unmodified from the client
2493 to the server in the new Access-Request reply to that challenge,
2496 This Attribute is available to be sent by the server to the client
2497 in an Access-Accept that also includes a Termination-Action
2498 Attribute with the value of RADIUS-Request. If the NAS performs
2499 the Termination-Action by sending a new Access-Request upon
2500 termination of the current session, it MUST include the State
2501 attribute unchanged in that Access-Request.
2503 In either usage, the client MUST NOT interpret the attribute
2504 locally. A packet must have only zero or one State Attribute.
2505 Usage of the State Attribute is implementation dependent.
2507 A summary of the State Attribute format is shown below. The fields
2508 are transmitted from left to right.
2511 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2512 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2513 | Type | Length | String ...
2514 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2522 Rigney, et al. Standards Track [Page 45]
2524 RFC 2865 RADIUS June 2000
2533 The String field is one or more octets. The actual format of the
2534 information is site or application specific, and a robust
2535 implementation SHOULD support the field as undistinguished octets.
2537 The codification of the range of allowed usage of this field is
2538 outside the scope of this specification.
2544 This Attribute is available to be sent by the server to the client
2545 in an Access-Accept and SHOULD be sent unmodified by the client to
2546 the accounting server as part of the Accounting-Request packet if
2547 accounting is supported. The client MUST NOT interpret the
2550 A summary of the Class Attribute format is shown below. The fields
2551 are transmitted from left to right.
2554 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2555 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2556 | Type | Length | String ...
2557 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2569 The String field is one or more octets. The actual format of the
2570 information is site or application specific, and a robust
2571 implementation SHOULD support the field as undistinguished octets.
2573 The codification of the range of allowed usage of this field is
2574 outside the scope of this specification.
2578 Rigney, et al. Standards Track [Page 46]
2580 RFC 2865 RADIUS June 2000
2583 5.26. Vendor-Specific
2587 This Attribute is available to allow vendors to support their own
2588 extended Attributes not suitable for general usage. It MUST not
2589 affect the operation of the RADIUS protocol.
2591 Servers not equipped to interpret the vendor-specific information
2592 sent by a client MUST ignore it (although it may be reported).
2593 Clients which do not receive desired vendor-specific information
2594 SHOULD make an attempt to operate without it, although they may do
2595 so (and report they are doing so) in a degraded mode.
2597 A summary of the Vendor-Specific Attribute format is shown below.
2598 The fields are transmitted from left to right.
2601 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2602 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2603 | Type | Length | Vendor-Id
2604 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2605 Vendor-Id (cont) | String...
2606 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2610 26 for Vendor-Specific.
2618 The high-order octet is 0 and the low-order 3 octets are the SMI
2619 Network Management Private Enterprise Code of the Vendor in
2620 network byte order, as defined in the "Assigned Numbers" RFC [6].
2624 The String field is one or more octets. The actual format of the
2625 information is site or application specific, and a robust
2626 implementation SHOULD support the field as undistinguished octets.
2628 The codification of the range of allowed usage of this field is
2629 outside the scope of this specification.
2634 Rigney, et al. Standards Track [Page 47]
2636 RFC 2865 RADIUS June 2000
2639 It SHOULD be encoded as a sequence of vendor type / vendor length
2640 / value fields, as follows. The Attribute-Specific field is
2641 dependent on the vendor's definition of that attribute. An
2642 example encoding of the Vendor-Specific attribute using this
2646 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2647 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2648 | Type | Length | Vendor-Id
2649 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2650 Vendor-Id (cont) | Vendor type | Vendor length |
2651 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2652 | Attribute-Specific...
2653 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2655 Multiple subattributes MAY be encoded within a single Vendor-
2656 Specific attribute, although they do not have to be.
2658 5.27. Session-Timeout
2662 This Attribute sets the maximum number of seconds of service to be
2663 provided to the user before termination of the session or prompt.
2664 This Attribute is available to be sent by the server to the client
2665 in an Access-Accept or Access-Challenge.
2667 A summary of the Session-Timeout Attribute format is shown below.
2668 The fields are transmitted from left to right.
2671 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2672 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2673 | Type | Length | Value
2674 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2676 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2680 27 for Session-Timeout.
2690 Rigney, et al. Standards Track [Page 48]
2692 RFC 2865 RADIUS June 2000
2697 The field is 4 octets, containing a 32-bit unsigned integer with
2698 the maximum number of seconds this user should be allowed to
2699 remain connected by the NAS.
2705 This Attribute sets the maximum number of consecutive seconds of
2706 idle connection allowed to the user before termination of the
2707 session or prompt. This Attribute is available to be sent by the
2708 server to the client in an Access-Accept or Access-Challenge.
2710 A summary of the Idle-Timeout Attribute format is shown below. The
2711 fields are transmitted from left to right.
2714 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2715 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2716 | Type | Length | Value
2717 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2719 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2723 28 for Idle-Timeout.
2731 The field is 4 octets, containing a 32-bit unsigned integer with
2732 the maximum number of consecutive seconds of idle time this user
2733 should be permitted before being disconnected by the NAS.
2735 5.29. Termination-Action
2739 This Attribute indicates what action the NAS should take when the
2740 specified service is completed. It is only used in Access-Accept
2746 Rigney, et al. Standards Track [Page 49]
2748 RFC 2865 RADIUS June 2000
2751 A summary of the Termination-Action Attribute format is shown below.
2752 The fields are transmitted from left to right.
2755 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2756 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2757 | Type | Length | Value
2758 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2760 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2764 29 for Termination-Action.
2772 The Value field is four octets.
2777 If the Value is set to RADIUS-Request, upon termination of the
2778 specified service the NAS MAY send a new Access-Request to the
2779 RADIUS server, including the State attribute if any.
2781 5.30. Called-Station-Id
2785 This Attribute allows the NAS to send in the Access-Request packet
2786 the phone number that the user called, using Dialed Number
2787 Identification (DNIS) or similar technology. Note that this may
2788 be different from the phone number the call comes in on. It is
2789 only used in Access-Request packets.
2791 A summary of the Called-Station-Id Attribute format is shown below.
2792 The fields are transmitted from left to right.
2795 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2796 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2797 | Type | Length | String ...
2798 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2802 Rigney, et al. Standards Track [Page 50]
2804 RFC 2865 RADIUS June 2000
2809 30 for Called-Station-Id.
2817 The String field is one or more octets, containing the phone
2818 number that the user's call came in on.
2820 The actual format of the information is site or application
2821 specific. UTF-8 encoded 10646 [7] characters are recommended, but
2822 a robust implementation SHOULD support the field as
2823 undistinguished octets.
2825 The codification of the range of allowed usage of this field is
2826 outside the scope of this specification.
2828 5.31. Calling-Station-Id
2832 This Attribute allows the NAS to send in the Access-Request packet
2833 the phone number that the call came from, using Automatic Number
2834 Identification (ANI) or similar technology. It is only used in
2835 Access-Request packets.
2837 A summary of the Calling-Station-Id Attribute format is shown below.
2838 The fields are transmitted from left to right.
2841 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2842 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2843 | Type | Length | String ...
2844 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2848 31 for Calling-Station-Id.
2858 Rigney, et al. Standards Track [Page 51]
2860 RFC 2865 RADIUS June 2000
2865 The String field is one or more octets, containing the phone
2866 number that the user placed the call from.
2868 The actual format of the information is site or application
2869 specific. UTF-8 encoded 10646 [7] characters are recommended, but
2870 a robust implementation SHOULD support the field as
2871 undistinguished octets.
2873 The codification of the range of allowed usage of this field is
2874 outside the scope of this specification.
2876 5.32. NAS-Identifier
2880 This Attribute contains a string identifying the NAS originating
2881 the Access-Request. It is only used in Access-Request packets.
2882 Either NAS-IP-Address or NAS-Identifier MUST be present in an
2883 Access-Request packet.
2885 Note that NAS-Identifier MUST NOT be used to select the shared
2886 secret used to authenticate the request. The source IP address of
2887 the Access-Request packet MUST be used to select the shared
2890 A summary of the NAS-Identifier Attribute format is shown below. The
2891 fields are transmitted from left to right.
2894 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2895 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2896 | Type | Length | String ...
2897 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2901 32 for NAS-Identifier.
2914 Rigney, et al. Standards Track [Page 52]
2916 RFC 2865 RADIUS June 2000
2921 The String field is one or more octets, and should be unique to
2922 the NAS within the scope of the RADIUS server. For example, a
2923 fully qualified domain name would be suitable as a NAS-Identifier.
2925 The actual format of the information is site or application
2926 specific, and a robust implementation SHOULD support the field as
2927 undistinguished octets.
2929 The codification of the range of allowed usage of this field is
2930 outside the scope of this specification.
2936 This Attribute is available to be sent by a proxy server to
2937 another server when forwarding an Access-Request and MUST be
2938 returned unmodified in the Access-Accept, Access-Reject or
2939 Access-Challenge. When the proxy server receives the response to
2940 its request, it MUST remove its own Proxy-State (the last Proxy-
2941 State in the packet) before forwarding the response to the NAS.
2943 If a Proxy-State Attribute is added to a packet when forwarding
2944 the packet, the Proxy-State Attribute MUST be added after any
2945 existing Proxy-State attributes.
2947 The content of any Proxy-State other than the one added by the
2948 current server should be treated as opaque octets and MUST NOT
2949 affect operation of the protocol.
2951 Usage of the Proxy-State Attribute is implementation dependent. A
2952 description of its function is outside the scope of this
2955 A summary of the Proxy-State Attribute format is shown below. The
2956 fields are transmitted from left to right.
2959 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2960 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2961 | Type | Length | String ...
2962 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
2970 Rigney, et al. Standards Track [Page 53]
2972 RFC 2865 RADIUS June 2000
2981 The String field is one or more octets. The actual format of the
2982 information is site or application specific, and a robust
2983 implementation SHOULD support the field as undistinguished octets.
2985 The codification of the range of allowed usage of this field is
2986 outside the scope of this specification.
2988 5.34. Login-LAT-Service
2992 This Attribute indicates the system with which the user is to be
2993 connected by LAT. It MAY be used in Access-Accept packets, but
2994 only when LAT is specified as the Login-Service. It MAY be used
2995 in an Access-Request packet as a hint to the server, but the
2996 server is not required to honor the hint.
2998 Administrators use the service attribute when dealing with
2999 clustered systems, such as a VAX or Alpha cluster. In such an
3000 environment several different time sharing hosts share the same
3001 resources (disks, printers, etc.), and administrators often
3002 configure each to offer access (service) to each of the shared
3003 resources. In this case, each host in the cluster advertises its
3004 services through LAT broadcasts.
3006 Sophisticated users often know which service providers (machines)
3007 are faster and tend to use a node name when initiating a LAT
3008 connection. Alternately, some administrators want particular
3009 users to use certain machines as a primitive form of load
3010 balancing (although LAT knows how to do load balancing itself).
3012 A summary of the Login-LAT-Service Attribute format is shown below.
3013 The fields are transmitted from left to right.
3016 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3017 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3018 | Type | Length | String ...
3019 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3026 Rigney, et al. Standards Track [Page 54]
3028 RFC 2865 RADIUS June 2000
3033 34 for Login-LAT-Service.
3041 The String field is one or more octets, and contains the identity
3042 of the LAT service to use. The LAT Architecture allows this
3043 string to contain $ (dollar), - (hyphen), . (period), _
3044 (underscore), numerics, upper and lower case alphabetics, and the
3045 ISO Latin-1 character set extension [11]. All LAT string
3046 comparisons are case insensitive.
3048 5.35. Login-LAT-Node
3052 This Attribute indicates the Node with which the user is to be
3053 automatically connected by LAT. It MAY be used in Access-Accept
3054 packets, but only when LAT is specified as the Login-Service. It
3055 MAY be used in an Access-Request packet as a hint to the server,
3056 but the server is not required to honor the hint.
3058 A summary of the Login-LAT-Node Attribute format is shown below. The
3059 fields are transmitted from left to right.
3062 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3063 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3064 | Type | Length | String ...
3065 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3069 35 for Login-LAT-Node.
3082 Rigney, et al. Standards Track [Page 55]
3084 RFC 2865 RADIUS June 2000
3089 The String field is one or more octets, and contains the identity
3090 of the LAT Node to connect the user to. The LAT Architecture
3091 allows this string to contain $ (dollar), - (hyphen), . (period),
3092 _ (underscore), numerics, upper and lower case alphabetics, and
3093 the ISO Latin-1 character set extension. All LAT string
3094 comparisons are case insensitive.
3096 5.36. Login-LAT-Group
3100 This Attribute contains a string identifying the LAT group codes
3101 which this user is authorized to use. It MAY be used in Access-
3102 Accept packets, but only when LAT is specified as the Login-
3103 Service. It MAY be used in an Access-Request packet as a hint to
3104 the server, but the server is not required to honor the hint.
3106 LAT supports 256 different group codes, which LAT uses as a form
3107 of access rights. LAT encodes the group codes as a 256 bit
3110 Administrators can assign one or more of the group code bits at
3111 the LAT service provider; it will only accept LAT connections that
3112 have these group codes set in the bit map. The administrators
3113 assign a bitmap of authorized group codes to each user; LAT gets
3114 these from the operating system, and uses these in its requests to
3115 the service providers.
3117 A summary of the Login-LAT-Group Attribute format is shown below.
3118 The fields are transmitted from left to right.
3121 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3122 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3123 | Type | Length | String ...
3124 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3128 36 for Login-LAT-Group.
3138 Rigney, et al. Standards Track [Page 56]
3140 RFC 2865 RADIUS June 2000
3145 The String field is a 32 octet bit map, most significant octet
3146 first. A robust implementation SHOULD support the field as
3147 undistinguished octets.
3149 The codification of the range of allowed usage of this field is
3150 outside the scope of this specification.
3152 5.37. Framed-AppleTalk-Link
3156 This Attribute indicates the AppleTalk network number which should
3157 be used for the serial link to the user, which is another
3158 AppleTalk router. It is only used in Access-Accept packets. It
3159 is never used when the user is not another router.
3161 A summary of the Framed-AppleTalk-Link Attribute format is shown
3162 below. The fields are transmitted from left to right.
3165 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3166 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3167 | Type | Length | Value
3168 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3170 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3174 37 for Framed-AppleTalk-Link.
3182 The Value field is four octets. Despite the size of the field,
3183 values range from 0 to 65535. The special value of 0 indicates
3184 that this is an unnumbered serial link. A value of 1-65535 means
3185 that the serial line between the NAS and the user should be
3186 assigned that value as an AppleTalk network number.
3194 Rigney, et al. Standards Track [Page 57]
3196 RFC 2865 RADIUS June 2000
3199 5.38. Framed-AppleTalk-Network
3203 This Attribute indicates the AppleTalk Network number which the
3204 NAS should probe to allocate an AppleTalk node for the user. It
3205 is only used in Access-Accept packets. It is never used when the
3206 user is another router. Multiple instances of this Attribute
3207 indicate that the NAS may probe using any of the network numbers
3210 A summary of the Framed-AppleTalk-Network Attribute format is shown
3211 below. The fields are transmitted from left to right.
3214 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3215 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3216 | Type | Length | Value
3217 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3219 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3223 38 for Framed-AppleTalk-Network.
3231 The Value field is four octets. Despite the size of the field,
3232 values range from 0 to 65535. The special value 0 indicates that
3233 the NAS should assign a network for the user, using its default
3234 cable range. A value between 1 and 65535 (inclusive) indicates
3235 the AppleTalk Network the NAS should probe to find an address for
3238 5.39. Framed-AppleTalk-Zone
3242 This Attribute indicates the AppleTalk Default Zone to be used for
3243 this user. It is only used in Access-Accept packets. Multiple
3244 instances of this attribute in the same packet are not allowed.
3250 Rigney, et al. Standards Track [Page 58]
3252 RFC 2865 RADIUS June 2000
3255 A summary of the Framed-AppleTalk-Zone Attribute format is shown
3256 below. The fields are transmitted from left to right.
3259 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4
3260 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3261 | Type | Length | String ...
3262 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3266 39 for Framed-AppleTalk-Zone.
3274 The name of the Default AppleTalk Zone to be used for this user.
3275 A robust implementation SHOULD support the field as
3276 undistinguished octets.
3278 The codification of the range of allowed usage of this field is
3279 outside the scope of this specification.
3281 5.40. CHAP-Challenge
3285 This Attribute contains the CHAP Challenge sent by the NAS to a
3286 PPP Challenge-Handshake Authentication Protocol (CHAP) user. It
3287 is only used in Access-Request packets.
3289 If the CHAP challenge value is 16 octets long it MAY be placed in
3290 the Request Authenticator field instead of using this attribute.
3292 A summary of the CHAP-Challenge Attribute format is shown below. The
3293 fields are transmitted from left to right.
3296 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
3297 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3298 | Type | Length | String...
3299 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3306 Rigney, et al. Standards Track [Page 59]
3308 RFC 2865 RADIUS June 2000
3313 60 for CHAP-Challenge.
3321 The String field contains the CHAP Challenge.
3327 This Attribute indicates the type of the physical port of the NAS
3328 which is authenticating the user. It can be used instead of or in
3329 addition to the NAS-Port (5) attribute. It is only used in
3330 Access-Request packets. Either NAS-Port (5) or NAS-Port-Type or
3331 both SHOULD be present in an Access-Request packet, if the NAS
3332 differentiates among its ports.
3334 A summary of the NAS-Port-Type Attribute format is shown below. The
3335 fields are transmitted from left to right.
3338 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3339 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3340 | Type | Length | Value
3341 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3343 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3347 61 for NAS-Port-Type.
3355 The Value field is four octets. "Virtual" refers to a connection
3356 to the NAS via some transport protocol, instead of through a
3357 physical port. For example, if a user telnetted into a NAS to
3362 Rigney, et al. Standards Track [Page 60]
3364 RFC 2865 RADIUS June 2000
3367 authenticate himself as an Outbound-User, the Access-Request might
3368 include NAS-Port-Type = Virtual as a hint to the RADIUS server
3369 that the user was not on a physical port.
3378 7 HDLC Clear Channel
3382 11 SDSL - Symmetric DSL
3383 12 ADSL-CAP - Asymmetric DSL, Carrierless Amplitude Phase
3385 13 ADSL-DMT - Asymmetric DSL, Discrete Multi-Tone
3386 14 IDSL - ISDN Digital Subscriber Line
3388 16 xDSL - Digital Subscriber Line of unknown type
3391 19 Wireless - IEEE 802.11
3393 PIAFS is a form of wireless ISDN commonly used in Japan, and
3394 stands for PHS (Personal Handyphone System) Internet Access Forum
3401 This Attribute sets the maximum number of ports to be provided to
3402 the user by the NAS. This Attribute MAY be sent by the server to
3403 the client in an Access-Accept packet. It is intended for use in
3404 conjunction with Multilink PPP [12] or similar uses. It MAY also
3405 be sent by the NAS to the server as a hint that that many ports
3406 are desired for use, but the server is not required to honor the
3409 A summary of the Port-Limit Attribute format is shown below. The
3410 fields are transmitted from left to right.
3418 Rigney, et al. Standards Track [Page 61]
3420 RFC 2865 RADIUS June 2000
3424 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3425 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3426 | Type | Length | Value
3427 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3429 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3441 The field is 4 octets, containing a 32-bit unsigned integer with
3442 the maximum number of ports this user should be allowed to connect
3445 5.43. Login-LAT-Port
3449 This Attribute indicates the Port with which the user is to be
3450 connected by LAT. It MAY be used in Access-Accept packets, but
3451 only when LAT is specified as the Login-Service. It MAY be used
3452 in an Access-Request packet as a hint to the server, but the
3453 server is not required to honor the hint.
3455 A summary of the Login-LAT-Port Attribute format is shown below. The
3456 fields are transmitted from left to right.
3459 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3460 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3461 | Type | Length | String ...
3462 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
3466 63 for Login-LAT-Port.
3474 Rigney, et al. Standards Track [Page 62]
3476 RFC 2865 RADIUS June 2000
3481 The String field is one or more octets, and contains the identity
3482 of the LAT port to use. The LAT Architecture allows this string
3483 to contain $ (dollar), - (hyphen), . (period), _ (underscore),
3484 numerics, upper and lower case alphabetics, and the ISO Latin-1
3485 character set extension. All LAT string comparisons are case
3488 5.44. Table of Attributes
3490 The following table provides a guide to which attributes may be found
3491 in which kinds of packets, and in what quantity.
3493 Request Accept Reject Challenge # Attribute
3494 0-1 0-1 0 0 1 User-Name
3495 0-1 0 0 0 2 User-Password [Note 1]
3496 0-1 0 0 0 3 CHAP-Password [Note 1]
3497 0-1 0 0 0 4 NAS-IP-Address [Note 2]
3498 0-1 0 0 0 5 NAS-Port
3499 0-1 0-1 0 0 6 Service-Type
3500 0-1 0-1 0 0 7 Framed-Protocol
3501 0-1 0-1 0 0 8 Framed-IP-Address
3502 0-1 0-1 0 0 9 Framed-IP-Netmask
3503 0 0-1 0 0 10 Framed-Routing
3504 0 0+ 0 0 11 Filter-Id
3505 0-1 0-1 0 0 12 Framed-MTU
3506 0+ 0+ 0 0 13 Framed-Compression
3507 0+ 0+ 0 0 14 Login-IP-Host
3508 0 0-1 0 0 15 Login-Service
3509 0 0-1 0 0 16 Login-TCP-Port
3510 0 0+ 0+ 0+ 18 Reply-Message
3511 0-1 0-1 0 0 19 Callback-Number
3512 0 0-1 0 0 20 Callback-Id
3513 0 0+ 0 0 22 Framed-Route
3514 0 0-1 0 0 23 Framed-IPX-Network
3515 0-1 0-1 0 0-1 24 State [Note 1]
3517 0+ 0+ 0 0+ 26 Vendor-Specific
3518 0 0-1 0 0-1 27 Session-Timeout
3519 0 0-1 0 0-1 28 Idle-Timeout
3520 0 0-1 0 0 29 Termination-Action
3521 0-1 0 0 0 30 Called-Station-Id
3522 0-1 0 0 0 31 Calling-Station-Id
3523 0-1 0 0 0 32 NAS-Identifier [Note 2]
3524 0+ 0+ 0+ 0+ 33 Proxy-State
3525 0-1 0-1 0 0 34 Login-LAT-Service
3526 0-1 0-1 0 0 35 Login-LAT-Node
3530 Rigney, et al. Standards Track [Page 63]
3532 RFC 2865 RADIUS June 2000
3535 0-1 0-1 0 0 36 Login-LAT-Group
3536 0 0-1 0 0 37 Framed-AppleTalk-Link
3537 0 0+ 0 0 38 Framed-AppleTalk-Network
3538 0 0-1 0 0 39 Framed-AppleTalk-Zone
3539 0-1 0 0 0 60 CHAP-Challenge
3540 0-1 0 0 0 61 NAS-Port-Type
3541 0-1 0-1 0 0 62 Port-Limit
3542 0-1 0-1 0 0 63 Login-LAT-Port
3543 Request Accept Reject Challenge # Attribute
3545 [Note 1] An Access-Request MUST contain either a User-Password or a
3546 CHAP-Password or State. An Access-Request MUST NOT contain both a
3547 User-Password and a CHAP-Password. If future extensions allow other
3548 kinds of authentication information to be conveyed, the attribute for
3549 that can be used in an Access-Request instead of User-Password or
3552 [Note 2] An Access-Request MUST contain either a NAS-IP-Address or a
3553 NAS-Identifier (or both).
3555 The following table defines the meaning of the above table entries.
3557 0 This attribute MUST NOT be present in packet.
3558 0+ Zero or more instances of this attribute MAY be present in packet.
3559 0-1 Zero or one instance of this attribute MAY be present in packet.
3560 1 Exactly one instance of this attribute MUST be present in packet.
3562 6. IANA Considerations
3564 This section provides guidance to the Internet Assigned Numbers
3565 Authority (IANA) regarding registration of values related to the
3566 RADIUS protocol, in accordance with BCP 26 [13].
3568 There are three name spaces in RADIUS that require registration:
3569 Packet Type Codes, Attribute Types, and Attribute Values (for certain
3572 RADIUS is not intended as a general-purpose Network Access Server
3573 (NAS) management protocol, and allocations should not be made for
3574 purposes unrelated to Authentication, Authorization or Accounting.
3576 6.1. Definition of Terms
3578 The following terms are used here with the meanings defined in
3579 BCP 26: "name space", "assigned value", "registration".
3586 Rigney, et al. Standards Track [Page 64]
3588 RFC 2865 RADIUS June 2000
3591 The following policies are used here with the meanings defined in
3592 BCP 26: "Private Use", "First Come First Served", "Expert Review",
3593 "Specification Required", "IETF Consensus", "Standards Action".
3595 6.2. Recommended Registration Policies
3597 For registration requests where a Designated Expert should be
3598 consulted, the IESG Area Director for Operations should appoint the
3601 For registration requests requiring Expert Review, the ietf-radius
3602 mailing list should be consulted.
3604 Packet Type Codes have a range from 1 to 254, of which 1-5,11-13 have
3605 been allocated. Because a new Packet Type has considerable impact on
3606 interoperability, a new Packet Type Code requires Standards Action,
3607 and should be allocated starting at 14.
3609 Attribute Types have a range from 1 to 255, and are the scarcest
3610 resource in RADIUS, thus must be allocated with care. Attributes
3611 1-53,55,60-88,90-91 have been allocated, with 17 and 21 available for
3612 re-use. Attributes 17, 21, 54, 56-59, 89, 92-191 may be allocated
3613 following Expert Review, with Specification Required. Release of
3614 blocks of Attribute Types (more than 3 at a time for a given purpose)
3615 should require IETF Consensus. It is recommended that attributes 17
3616 and 21 be used only after all others are exhausted.
3618 Note that RADIUS defines a mechanism for Vendor-Specific extensions
3619 (Attribute 26) and the use of that should be encouraged instead of
3620 allocation of global attribute types, for functions specific only to
3621 one vendor's implementation of RADIUS, where no interoperability is
3624 As stated in the "Attributes" section above:
3626 "[Attribute Type] Values 192-223 are reserved for experimental
3627 use, values 224-240 are reserved for implementation-specific use,
3628 and values 241-255 are reserved and should not be used."
3630 Therefore Attribute values 192-240 are considered Private Use, and
3631 values 241-255 require Standards Action.
3633 Certain attributes (for example, NAS-Port-Type) in RADIUS define a
3634 list of values to correspond with various meanings. There can be 4
3635 billion (2^32) values for each attribute. Adding additional values to
3636 the list can be done on a First Come, First Served basis by the IANA.
3642 Rigney, et al. Standards Track [Page 65]
3644 RFC 2865 RADIUS June 2000
3649 A few examples are presented to illustrate the flow of packets and
3650 use of typical attributes. These examples are not intended to be
3651 exhaustive, many others are possible. Hexadecimal dumps of the
3652 example packets are given in network byte order, using the shared
3655 7.1. User Telnet to Specified Host
3657 The NAS at 192.168.1.16 sends an Access-Request UDP packet to the
3658 RADIUS Server for a user named nemo logging in on port 3 with
3659 password "arctangent".
3661 The Request Authenticator is a 16 octet random number generated by
3664 The User-Password is 16 octets of password padded at end with nulls,
3665 XORed with MD5(shared secret|Request Authenticator).
3667 01 00 00 38 0f 40 3f 94 73 97 80 57 bd 83 d5 cb
3668 98 f4 22 7a 01 06 6e 65 6d 6f 02 12 0d be 70 8d
3669 93 d4 13 ce 31 96 e4 3f 78 2a 0a ee 04 06 c0 a8
3670 01 10 05 06 00 00 00 03
3672 1 Code = Access-Request (1)
3675 16 Request Authenticator
3678 6 User-Name = "nemo"
3680 6 NAS-IP-Address = 192.168.1.16
3683 The RADIUS server authenticates nemo, and sends an Access-Accept UDP
3684 packet to the NAS telling it to telnet nemo to host 192.168.1.3.
3686 The Response Authenticator is a 16-octet MD5 checksum of the code
3687 (2), id (0), Length (38), the Request Authenticator from above, the
3688 attributes in this reply, and the shared secret.
3698 Rigney, et al. Standards Track [Page 66]
3700 RFC 2865 RADIUS June 2000
3703 02 00 00 26 86 fe 22 0e 76 24 ba 2a 10 05 f6 bf
3704 9b 55 e0 b2 06 06 00 00 00 01 0f 06 00 00 00 00
3707 1 Code = Access-Accept (2)
3708 1 ID = 0 (same as in Access-Request)
3710 16 Response Authenticator
3713 6 Service-Type (6) = Login (1)
3714 6 Login-Service (15) = Telnet (0)
3715 6 Login-IP-Host (14) = 192.168.1.3
3717 7.2. Framed User Authenticating with CHAP
3719 The NAS at 192.168.1.16 sends an Access-Request UDP packet to the
3720 RADIUS Server for a user named flopsy logging in on port 20 with PPP,
3721 authenticating using CHAP. The NAS sends along the Service-Type and
3722 Framed-Protocol attributes as a hint to the RADIUS server that this
3723 user is looking for PPP, although the NAS is not required to do so.
3725 The Request Authenticator is a 16 octet random number generated by
3726 the NAS, and is also used as the CHAP Challenge.
3728 The CHAP-Password consists of a 1 octet CHAP ID, in this case 22,
3729 followed by the 16 octet CHAP response.
3731 01 01 00 47 2a ee 86 f0 8d 0d 55 96 9c a5 97 8e
3732 0d 33 67 a2 01 08 66 6c 6f 70 73 79 03 13 16 e9
3733 75 57 c3 16 18 58 95 f2 93 ff 63 44 07 72 75 04
3734 06 c0 a8 01 10 05 06 00 00 00 14 06 06 00 00 00
3735 02 07 06 00 00 00 01
3737 1 Code = 1 (Access-Request)
3740 16 Request Authenticator
3743 8 User-Name (1) = "flopsy"
3744 19 CHAP-Password (3)
3745 6 NAS-IP-Address (4) = 192.168.1.16
3747 6 Service-Type (6) = Framed (2)
3748 6 Framed-Protocol (7) = PPP (1)
3754 Rigney, et al. Standards Track [Page 67]
3756 RFC 2865 RADIUS June 2000
3759 The RADIUS server authenticates flopsy, and sends an Access-Accept
3760 UDP packet to the NAS telling it to start PPP service and assign an
3761 address for the user out of its dynamic address pool.
3763 The Response Authenticator is a 16-octet MD5 checksum of the code
3764 (2), id (1), Length (56), the Request Authenticator from above, the
3765 attributes in this reply, and the shared secret.
3767 02 01 00 38 15 ef bc 7d ab 26 cf a3 dc 34 d9 c0
3768 3c 86 01 a4 06 06 00 00 00 02 07 06 00 00 00 01
3769 08 06 ff ff ff fe 0a 06 00 00 00 02 0d 06 00 00
3770 00 01 0c 06 00 00 05 dc
3772 1 Code = Access-Accept (2)
3773 1 ID = 1 (same as in Access-Request)
3775 16 Response Authenticator
3778 6 Service-Type (6) = Framed (2)
3779 6 Framed-Protocol (7) = PPP (1)
3780 6 Framed-IP-Address (8) = 255.255.255.254
3781 6 Framed-Routing (10) = None (0)
3782 6 Framed-Compression (13) = VJ TCP/IP Header Compression (1)
3783 6 Framed-MTU (12) = 1500
3785 7.3. User with Challenge-Response card
3787 The NAS at 192.168.1.16 sends an Access-Request UDP packet to the
3788 RADIUS Server for a user named mopsy logging in on port 7. The user
3789 enters the dummy password "challenge" in this example. The challenge
3790 and response generated by the smart card for this example are
3791 "32769430" and "99101462".
3793 The Request Authenticator is a 16 octet random number generated by
3796 The User-Password is 16 octets of password, in this case "challenge",
3797 padded at the end with nulls, XORed with MD5(shared secret|Request
3800 01 02 00 39 f3 a4 7a 1f 6a 6d 76 71 0b 94 7a b9
3801 30 41 a0 39 01 07 6d 6f 70 73 79 02 12 33 65 75
3802 73 77 82 89 b5 70 88 5e 15 08 48 25 c5 04 06 c0
3803 a8 01 10 05 06 00 00 00 07
3810 Rigney, et al. Standards Track [Page 68]
3812 RFC 2865 RADIUS June 2000
3815 1 Code = Access-Request (1)
3818 16 Request Authenticator
3821 7 User-Name (1) = "mopsy"
3822 18 User-Password (2)
3823 6 NAS-IP-Address (4) = 192.168.1.16
3826 The RADIUS server decides to challenge mopsy, sending back a
3827 challenge string and looking for a response. The RADIUS server
3828 therefore and sends an Access-Challenge UDP packet to the NAS.
3830 The Response Authenticator is a 16-octet MD5 checksum of the code
3831 (11), id (2), length (78), the Request Authenticator from above, the
3832 attributes in this reply, and the shared secret.
3834 The Reply-Message is "Challenge 32769430. Enter response at prompt."
3836 The State is a magic cookie to be returned along with user's
3837 response; in this example 8 octets of data (33 32 37 36 39 34 33 30
3840 0b 02 00 4e 36 f3 c8 76 4a e8 c7 11 57 40 3c 0c
3841 71 ff 9c 45 12 30 43 68 61 6c 6c 65 6e 67 65 20
3842 33 32 37 36 39 34 33 30 2e 20 20 45 6e 74 65 72
3843 20 72 65 73 70 6f 6e 73 65 20 61 74 20 70 72 6f
3844 6d 70 74 2e 18 0a 33 32 37 36 39 34 33 30
3846 1 Code = Access-Challenge (11)
3847 1 ID = 2 (same as in Access-Request)
3849 16 Response Authenticator
3852 48 Reply-Message (18)
3855 The user enters his response, and the NAS send a new Access-Request
3856 with that response, and includes the State Attribute.
3858 The Request Authenticator is a new 16 octet random number.
3860 The User-Password is 16 octets of the user's response, in this case
3861 "99101462", padded at the end with nulls, XORed with MD5(shared
3862 secret|Request Authenticator).
3866 Rigney, et al. Standards Track [Page 69]
3868 RFC 2865 RADIUS June 2000
3871 The state is the magic cookie from the Access-Challenge packet,
3874 01 03 00 43 b1 22 55 6d 42 8a 13 d0 d6 25 38 07
3875 c4 57 ec f0 01 07 6d 6f 70 73 79 02 12 69 2c 1f
3876 20 5f c0 81 b9 19 b9 51 95 f5 61 a5 81 04 06 c0
3877 a8 01 10 05 06 00 00 00 07 18 10 33 32 37 36 39
3880 1 Code = Access-Request (1)
3881 1 ID = 3 (Note that this changes.)
3883 16 Request Authenticator
3886 7 User-Name = "mopsy"
3888 6 NAS-IP-Address (4) = 192.168.1.16
3892 The Response was incorrect (for the sake of example), so the RADIUS
3893 server tells the NAS to reject the login attempt.
3895 The Response Authenticator is a 16 octet MD5 checksum of the code
3896 (3), id (3), length(20), the Request Authenticator from above, the
3897 attributes in this reply (in this case, none), and the shared secret.
3899 03 03 00 14 a4 2f 4f ca 45 91 6c 4e 09 c8 34 0f
3902 1 Code = Access-Reject (3)
3903 1 ID = 3 (same as in Access-Request)
3905 16 Response Authenticator
3908 (none, although a Reply-Message could be sent)
3922 Rigney, et al. Standards Track [Page 70]
3924 RFC 2865 RADIUS June 2000
3927 8. Security Considerations
3929 Security issues are the primary topic of this document.
3931 In practice, within or associated with each RADIUS server, there is a
3932 database which associates "user" names with authentication
3933 information ("secrets"). It is not anticipated that a particular
3934 named user would be authenticated by multiple methods. This would
3935 make the user vulnerable to attacks which negotiate the least secure
3936 method from among a set. Instead, for each named user there should
3937 be an indication of exactly one method used to authenticate that user
3938 name. If a user needs to make use of different authentication
3939 methods under different circumstances, then distinct user names
3940 SHOULD be employed, each of which identifies exactly one
3941 authentication method.
3943 Passwords and other secrets should be stored at the respective ends
3944 such that access to them is as limited as possible. Ideally, the
3945 secrets should only be accessible to the process requiring access in
3946 order to perform the authentication.
3948 The secrets should be distributed with a mechanism that limits the
3949 number of entities that handle (and thus gain knowledge of) the
3950 secret. Ideally, no unauthorized person should ever gain knowledge
3951 of the secrets. It is possible to achieve this with SNMP Security
3952 Protocols [14], but such a mechanism is outside the scope of this
3955 Other distribution methods are currently undergoing research and
3956 experimentation. The SNMP Security document [14] also has an
3957 excellent overview of threats to network protocols.
3959 The User-Password hiding mechanism described in Section 5.2 has not
3960 been subjected to significant amounts of cryptanalysis in the
3961 published literature. Some in the IETF community are concerned that
3962 this method might not provide sufficient confidentiality protection
3963 [15] to passwords transmitted using RADIUS. Users should evaluate
3964 their threat environment and consider whether additional security
3965 mechanisms should be employed.
3969 The following changes have been made from RFC 2138:
3971 Strings should use UTF-8 instead of US-ASCII and should be handled as
3974 Integers and dates are now defined as 32 bit unsigned values.
3978 Rigney, et al. Standards Track [Page 71]
3980 RFC 2865 RADIUS June 2000
3983 Updated list of attributes that can be included in Access-Challenge
3984 to be consistent with the table of attributes.
3986 User-Name mentions Network Access Identifiers.
3988 User-Name may now be sent in Access-Accept for use with accounting
3991 Values added for Service-Type, Login-Service, Framed-Protocol,
3992 Framed-Compression, and NAS-Port-Type.
3994 NAS-Port can now use all 32 bits.
3996 Examples now include hexadecimal displays of the packets.
3998 Source UDP port must be used in conjunction with the Request
3999 Identifier when identifying duplicates.
4001 Multiple subattributes may be allowed in a Vendor-Specific attribute.
4003 An Access-Request is now required to contain either a NAS-IP-Address
4004 or NAS-Identifier (or may contain both).
4006 Added notes under "Operations" with more information on proxy,
4007 retransmissions, and keep-alives.
4009 If multiple Attributes with the same Type are present, the order of
4010 Attributes with the same Type MUST be preserved by any proxies.
4012 Clarified Proxy-State.
4014 Clarified that Attributes must not depend on position within the
4015 packet, as long as Attributes of the same type are kept in order.
4017 Added IANA Considerations section.
4019 Updated section on "Proxy" under "Operations".
4021 Framed-MTU can now be sent in Access-Request as a hint.
4023 Updated Security Considerations.
4025 Text strings identified as a subset of string, to clarify use of
4034 Rigney, et al. Standards Track [Page 72]
4036 RFC 2865 RADIUS June 2000
4041 [1] Rigney, C., Rubens, A., Simpson, W. and S. Willens, "Remote
4042 Authentication Dial In User Service (RADIUS)", RFC 2138, April
4045 [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
4046 Levels", BCP 14, RFC 2119, March, 1997.
4048 [3] Rivest, R. and S. Dusse, "The MD5 Message-Digest Algorithm",
4049 RFC 1321, April 1992.
4051 [4] Postel, J., "User Datagram Protocol", STD 6, RFC 768, August
4054 [5] Rigney, C., "RADIUS Accounting", RFC 2866, June 2000.
4056 [6] Reynolds, J. and J. Postel, "Assigned Numbers", STD 2, RFC
4059 [7] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC
4062 [8] Aboba, B. and M. Beadles, "The Network Access Identifier", RFC
4065 [9] Kaufman, C., Perlman, R., and Speciner, M., "Network Security:
4066 Private Communications in a Public World", Prentice Hall, March
4067 1995, ISBN 0-13-061466-1.
4069 [10] Jacobson, V., "Compressing TCP/IP headers for low-speed serial
4070 links", RFC 1144, February 1990.
4072 [11] ISO 8859. International Standard -- Information Processing --
4073 8-bit Single-Byte Coded Graphic Character Sets -- Part 1: Latin
4074 Alphabet No. 1, ISO 8859-1:1987.
4076 [12] Sklower, K., Lloyd, B., McGregor, G., Carr, D. and T.
4077 Coradetti, "The PPP Multilink Protocol (MP)", RFC 1990, August
4080 [13] Alvestrand, H. and T. Narten, "Guidelines for Writing an IANA
4081 Considerations Section in RFCs", BCP 26, RFC 2434, October
4084 [14] Galvin, J., McCloghrie, K. and J. Davin, "SNMP Security
4085 Protocols", RFC 1352, July 1992.
4090 Rigney, et al. Standards Track [Page 73]
4092 RFC 2865 RADIUS June 2000
4095 [15] Dobbertin, H., "The Status of MD5 After a Recent Attack",
4096 CryptoBytes Vol.2 No.2, Summer 1996.
4098 11. Acknowledgements
4100 RADIUS was originally developed by Steve Willens of Livingston
4101 Enterprises for their PortMaster series of Network Access Servers.
4105 The working group can be contacted via the current chair:
4108 Livingston Enterprises
4110 Pleasanton, California 94588
4112 Phone: +1 925 737 2100
4113 EMail: cdr@telemancy.com
4146 Rigney, et al. Standards Track [Page 74]
4148 RFC 2865 RADIUS June 2000
4151 13. Authors' Addresses
4153 Questions about this memo can also be directed to:
4156 Livingston Enterprises
4158 Pleasanton, California 94588
4160 Phone: +1 925 737 2100
4161 EMail: cdr@telemancy.com
4167 Ann Arbor, Michigan 48105-2785
4169 EMail: acr@merit.edu
4172 William Allen Simpson
4174 Computer Systems Consulting Services
4176 Madison Heights, Michigan 48071
4178 EMail: wsimpson@greendragon.com
4182 Livingston Enterprises
4184 Pleasanton, California 94588
4186 EMail: steve@livingston.com
4202 Rigney, et al. Standards Track [Page 75]
4204 RFC 2865 RADIUS June 2000
4207 14. Full Copyright Statement
4209 Copyright (C) The Internet Society (2000). All Rights Reserved.
4211 This document and translations of it may be copied and furnished to
4212 others, and derivative works that comment on or otherwise explain it
4213 or assist in its implementation may be prepared, copied, published
4214 and distributed, in whole or in part, without restriction of any
4215 kind, provided that the above copyright notice and this paragraph are
4216 included on all such copies and derivative works. However, this
4217 document itself may not be modified in any way, such as by removing
4218 the copyright notice or references to the Internet Society or other
4219 Internet organizations, except as needed for the purpose of
4220 developing Internet standards in which case the procedures for
4221 copyrights defined in the Internet Standards process must be
4222 followed, or as required to translate it into languages other than
4225 The limited permissions granted above are perpetual and will not be
4226 revoked by the Internet Society or its successors or assigns.
4228 This document and the information contained herein is provided on an
4229 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
4230 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
4231 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
4232 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
4233 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
4237 Funding for the RFC Editor function is currently provided by the
4258 Rigney, et al. Standards Track [Page 76]