5.1. User-Name
Description
This Attribute indicates the name of the user to be authenticated.
It MUST be sent in Access-Request packets if available.
It MAY be sent in an Access-Accept packet, in which case the
client SHOULD use the name returned in the Access-Accept packet in
all Accounting-Request packets for this session. If the Access-
Accept includes Service-Type = Rlogin and the User-Name attribute,
a NAS MAY use the returned User-Name when performing the Rlogin
function.
A summary of the User-Name Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
1 for User-Name.
Length
>= 3
String
The String field is one or more octets. The NAS may limit the
maximum length of the User-Name but the ability to handle at least
63 octets is recommended.
The format of the username MAY be one of several forms:
text Consisting only of UTF-8 encoded 10646 [7] characters.
network access identifier
A Network Access Identifier as described in RFC2486
[8].
distinguished name
A name in ASN.1 form used in Public Key authentication
systems.
5.2. User-Password
Description
This Attribute indicates the password of the user to be
authenticated, or the user's input following an Access-Challenge.
It is only used in Access-Request packets.
On transmission, the password is hidden. The password is first
padded at the end with nulls to a multiple of 16 octets. A one-
way MD5 hash is calculated over a stream of octets consisting of
the shared secret followed by the Request Authenticator. This
value is XORed with the first 16 octet segment of the password and
placed in the first 16 octets of the String field of the User-
Password Attribute.
If the password is longer than 16 characters, a second one-way MD5
hash is calculated over a stream of octets consisting of the
shared secret followed by the result of the first xor. That hash
is XORed with the second 16 octet segment of the password and
placed in the second 16 octets of the String field of the User-
Password Attribute.
If necessary, this operation is repeated, with each xor result
being used along with the shared secret to generate the next hash
to xor the next segment of the password, to no more than 128
characters.
The method is taken from the book "Network Security" by Kaufman,
Perlman and Speciner [9] pages 109-110. A more precise
explanation of the method follows:
Call the shared secret S and the pseudo-random 128-bit Request
Authenticator RA. Break the password into 16-octet chunks p1, p2,
etc. with the last one padded at the end with nulls to a 16-octet
boundary. Call the ciphertext blocks c(1), c(2), etc. We'll need
intermediate values b1, b2, etc.
b1 = MD5(S + RA) c(1) = p1 xor b1
b2 = MD5(S + c(1)) c(2) = p2 xor b2
. .
. .
. .
bi = MD5(S + c(i-1)) c(i) = pi xor bi
The String will contain c(1)+c(2)+...+c(i) where + denotes
concatenation.
On receipt, the process is reversed to yield the original
password.
A summary of the User-Password Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
2 for User-Password.
Length
At least 18 and no larger than 130.
String
The String field is between 16 and 128 octets long, inclusive.
5.3. CHAP-Password
Description
This Attribute indicates the response value provided by a PPP
Challenge-Handshake Authentication Protocol (CHAP) user in
response to the challenge. It is only used in Access-Request
packets.
The CHAP challenge value is found in the CHAP-Challenge Attribute
(60) if present in the packet, otherwise in the Request
Authenticator field.
A summary of the CHAP-Password Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | CHAP Ident | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
3 for CHAP-Password.
Length
19
CHAP Ident
This field is one octet, and contains the CHAP Identifier from the
user's CHAP Response.
String
The String field is 16 octets, and contains the CHAP Response from
the user.
5.4. NAS-IP-Address
Description
This Attribute indicates the identifying IP Address of the NAS
which is requesting authentication of the user, and SHOULD be
unique to the NAS within the scope of the RADIUS server. NAS-IP-
Address is only used in Access-Request packets. Either NAS-IP-
Address or NAS-Identifier MUST be present in an Access-Request
packet.
Note that NAS-IP-Address MUST NOT be used to select the shared
secret used to authenticate the request. The source IP address of
the Access-Request packet MUST be used to select the shared
secret.
A summary of the NAS-IP-Address Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Address
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Address (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
4 for NAS-IP-Address.
Length
6
Address
The Address field is four octets.
5.5. NAS-Port
Description
This Attribute indicates the physical port number of the NAS which
is authenticating the user. It is only used in Access-Request
packets. Note that this is using "port" in its sense of a
physical connection on the NAS, not in the sense of a TCP or UDP
port number. Either NAS-Port or NAS-Port-Type (61) or both SHOULD
be present in an Access-Request packet, if the NAS differentiates
among its ports.
A summary of the NAS-Port Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
5 for NAS-Port.
Length
6
Value
The Value field is four octets.
5.6. Service-Type
Description
This Attribute indicates the type of service the user has
requested, or the type of service to be provided. It MAY be used
in both Access-Request and Access-Accept packets. A NAS is not
required to implement all of these service types, and MUST treat
unknown or unsupported Service-Types as though an Access-Reject
had been received instead.
A summary of the Service-Type Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
6 for Service-Type.
Length
6
Value
The Value field is four octets.
1 Login
2 Framed
3 Callback Login
4 Callback Framed
5 Outbound
6 Administrative
7 NAS Prompt
8 Authenticate Only
9 Callback NAS Prompt
10 Call Check
11 Callback Administrative
The service types are defined as follows when used in an Access-
Accept. When used in an Access-Request, they MAY be considered to
be a hint to the RADIUS server that the NAS has reason to believe
the user would prefer the kind of service indicated, but the
server is not required to honor the hint.
Login The user should be connected to a host.
Framed A Framed Protocol should be started for the
User, such as PPP or SLIP.
Callback Login The user should be disconnected and called
back, then connected to a host.
Callback Framed The user should be disconnected and called
back, then a Framed Protocol should be started
for the User, such as PPP or SLIP.
Outbound The user should be granted access to outgoing
devices.
Administrative The user should be granted access to the
administrative interface to the NAS from which
privileged commands can be executed.
NAS Prompt The user should be provided a command prompt
on the NAS from which non-privileged commands
can be executed.
Authenticate Only Only Authentication is requested, and no
authorization information needs to be returned
in the Access-Accept (typically used by proxy
servers rather than the NAS itself).
Callback NAS Prompt The user should be disconnected and called
back, then provided a command prompt on the
NAS from which non-privileged commands can be
executed.
Call Check Used by the NAS in an Access-Request packet to
indicate that a call is being received and
that the RADIUS server should send back an
Access-Accept to answer the call, or an
Access-Reject to not accept the call,
typically based on the Called-Station-Id or
Calling-Station-Id attributes. It is
recommended that such Access-Requests use the
value of Calling-Station-Id as the value of
the User-Name.
Callback Administrative
The user should be disconnected and called
back, then granted access to the
administrative interface to the NAS from which
privileged commands can be executed.
5.7. Framed-Protocol
Description
This Attribute indicates the framing to be used for framed access.
It MAY be used in both Access-Request and Access-Accept packets.
A summary of the Framed-Protocol Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
7 for Framed-Protocol.
Length
6
Value
The Value field is four octets.
1 PPP
2 SLIP
3 AppleTalk Remote Access Protocol (ARAP)
4 Gandalf proprietary SingleLink/MultiLink protocol
5 Xylogics proprietary IPX/SLIP
6 X.75 Synchronous
5.8. Framed-IP-Address
Description
This Attribute indicates the address to be configured for the
user. It MAY be used in Access-Accept packets. It MAY be used in
an Access-Request packet as a hint by the NAS to the server that
it would prefer that address, but the server is not required to
honor the hint.
A summary of the Framed-IP-Address Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Address
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Address (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
8 for Framed-IP-Address.
Length
6
Address
The Address field is four octets. The value 0xFFFFFFFF indicates
that the NAS Should allow the user to select an address (e.g.
Negotiated). The value 0xFFFFFFFE indicates that the NAS should
select an address for the user (e.g. Assigned from a pool of
addresses kept by the NAS). Other valid values indicate that the
NAS should use that value as the user's IP address.
5.9. Framed-IP-Netmask
Description
This Attribute indicates the IP netmask to be configured for the
user when the user is a router to a network. It MAY be used in
Access-Accept packets. It MAY be used in an Access-Request packet
as a hint by the NAS to the server that it would prefer that
netmask, but the server is not required to honor the hint.
A summary of the Framed-IP-Netmask Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Address
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Address (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
9 for Framed-IP-Netmask.
Length
6
Address
The Address field is four octets specifying the IP netmask of the
user.
5.10. Framed-Routing
Description
This Attribute indicates the routing method for the user, when the
user is a router to a network. It is only used in Access-Accept
packets.
A summary of the Framed-Routing Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
10 for Framed-Routing.
Length
6
Value
The Value field is four octets.
0 None
1 Send routing packets
2 Listen for routing packets
3 Send and Listen
5.11. Filter-Id
Description
This Attribute indicates the name of the filter list for this
user. Zero or more Filter-Id attributes MAY be sent in an
Access-Accept packet.
Identifying a filter list by name allows the filter to be used on
different NASes without regard to filter-list implementation
details.
A summary of the Filter-Id Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | Text ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
11 for Filter-Id.
Length
>= 3
Text
The Text field is one or more octets, and its contents are
implementation dependent. It is intended to be human readable and
MUST NOT affect operation of the protocol. It is recommended that
the message contain UTF-8 encoded 10646 [7] characters.
5.12. Framed-MTU
Description
This Attribute indicates the Maximum Transmission Unit to be
configured for the user, when it is not negotiated by some other
means (such as PPP). It MAY be used in Access-Accept packets. It
MAY be used in an Access-Request packet as a hint by the NAS to
the server that it would prefer that value, but the server is not
required to honor the hint.
A summary of the Framed-MTU Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
12 for Framed-MTU.
Length
6
Value
The Value field is four octets. Despite the size of the field,
values range from 64 to 65535.
5.13. Framed-Compression
Description
This Attribute indicates a compression protocol to be used for the
link. It MAY be used in Access-Accept packets. It MAY be used in
an Access-Request packet as a hint to the server that the NAS
would prefer to use that compression, but the server is not
required to honor the hint.
More than one compression protocol Attribute MAY be sent. It is
the responsibility of the NAS to apply the proper compression
protocol to appropriate link traffic.
A summary of the Framed-Compression Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
13 for Framed-Compression.
Length
6
Value
The Value field is four octets.
0 None
1 VJ TCP/IP header compression [10]
2 IPX header compression
3 Stac-LZS compression
5.14. Login-IP-Host
Description
This Attribute indicates the system with which to connect the user,
when the Login-Service Attribute is included. It MAY be used in
Access-Accept packets. It MAY be used in an Access-Request packet as
a hint to the server that the NAS would prefer to use that host, but
the server is not required to honor the hint.
A summary of the Login-IP-Host Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Address
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Address (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
14 for Login-IP-Host.
Length
6
Address
The Address field is four octets. The value 0xFFFFFFFF indicates
that the NAS SHOULD allow the user to select an address. The
value 0 indicates that the NAS SHOULD select a host to connect the
user to. Other values indicate the address the NAS SHOULD connect
the user to.
5.15. Login-Service
Description
This Attribute indicates the service to use to connect the user to
the login host. It is only used in Access-Accept packets.
A summary of the Login-Service Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
15 for Login-Service.
Length
6
Value
The Value field is four octets.
0 Telnet
1 Rlogin
2 TCP Clear
3 PortMaster (proprietary)
4 LAT
5 X25-PAD
6 X25-T3POS
8 TCP Clear Quiet (suppresses any NAS-generated connect string)
5.16. Login-TCP-Port
Description
This Attribute indicates the TCP port with which the user is to be
connected, when the Login-Service Attribute is also present. It
is only used in Access-Accept packets.
A summary of the Login-TCP-Port Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
16 for Login-TCP-Port.
Length
6
Value
The Value field is four octets. Despite the size of the field,
values range from 0 to 65535.
5.17. (unassigned)
Description
ATTRIBUTE TYPE 17 HAS NOT BEEN ASSIGNED.
5.18. Reply-Message
Description
This Attribute indicates text which MAY be displayed to the user.
When used in an Access-Accept, it is the success message.
When used in an Access-Reject, it is the failure message. It MAY
indicate a dialog message to prompt the user before another
Access-Request attempt.
When used in an Access-Challenge, it MAY indicate a dialog message
to prompt the user for a response.
Multiple Reply-Message's MAY be included and if any are displayed,
they MUST be displayed in the same order as they appear in the
packet.
A summary of the Reply-Message Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | Text ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
18 for Reply-Message.
Length
>= 3
Text
The Text field is one or more octets, and its contents are
implementation dependent. It is intended to be human readable,
and MUST NOT affect operation of the protocol. It is recommended
that the message contain UTF-8 encoded 10646 [7] characters.
5.19. Callback-Number
Description
This Attribute indicates a dialing string to be used for callback.
It MAY be used in Access-Accept packets. It MAY be used in an
Access-Request packet as a hint to the server that a Callback
service is desired, but the server is not required to honor the
hint.
A summary of the Callback-Number Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
19 for Callback-Number.
Length
>= 3
String
The String field is one or more octets. The actual format of the
information is site or application specific, and a robust
implementation SHOULD support the field as undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.20. Callback-Id
Description
This Attribute indicates the name of a place to be called, to be
interpreted by the NAS. It MAY be used in Access-Accept packets.
A summary of the Callback-Id Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
20 for Callback-Id.
Length
>= 3
String
The String field is one or more octets. The actual format of the
information is site or application specific, and a robust
implementation SHOULD support the field as undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.21. (unassigned)
Description
ATTRIBUTE TYPE 21 HAS NOT BEEN ASSIGNED.
5.22. Framed-Route
Description
This Attribute provides routing information to be configured for
the user on the NAS. It is used in the Access-Accept packet and
can appear multiple times.
A summary of the Framed-Route Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | Text ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
22 for Framed-Route.
Length
>= 3
Text
The Text field is one or more octets, and its contents are
implementation dependent. It is intended to be human readable and
MUST NOT affect operation of the protocol. It is recommended that
the message contain UTF-8 encoded 10646 [7] characters.
For IP routes, it SHOULD contain a destination prefix in dotted
quad form optionally followed by a slash and a decimal length
specifier stating how many high order bits of the prefix to use.
That is followed by a space, a gateway address in dotted quad
form, a space, and one or more metrics separated by spaces. For
example, "192.168.1.0/24 192.168.1.1 1 2 -1 3 400". The length
specifier may be omitted, in which case it defaults to 8 bits for
class A prefixes, 16 bits for class B prefixes, and 24 bits for
class C prefixes. For example, "192.168.1.0 192.168.1.1 1".
Whenever the gateway address is specified as "0.0.0.0" the IP
address of the user SHOULD be used as the gateway address.
5.23. Framed-IPX-Network
Description
This Attribute indicates the IPX Network number to be configured
for the user. It is used in Access-Accept packets.
A summary of the Framed-IPX-Network Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
23 for Framed-IPX-Network.
Length
6
Value
The Value field is four octets. The value 0xFFFFFFFE indicates
that the NAS should select an IPX network for the user (e.g.
assigned from a pool of one or more IPX networks kept by the NAS).
Other values should be used as the IPX network for the link to the
user.
5.24. State
Description
This Attribute is available to be sent by the server to the client
in an Access-Challenge and MUST be sent unmodified from the client
to the server in the new Access-Request reply to that challenge,
if any.
This Attribute is available to be sent by the server to the client
in an Access-Accept that also includes a Termination-Action
Attribute with the value of RADIUS-Request. If the NAS performs
the Termination-Action by sending a new Access-Request upon
termination of the current session, it MUST include the State
attribute unchanged in that Access-Request.
In either usage, the client MUST NOT interpret the attribute
locally. A packet must have only zero or one State Attribute.
Usage of the State Attribute is implementation dependent.
A summary of the State Attribute format is shown below. The fields
are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
24 for State.
Length
>= 3
String
The String field is one or more octets. The actual format of the
information is site or application specific, and a robust
implementation SHOULD support the field as undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.25. Class
Description
This Attribute is available to be sent by the server to the client
in an Access-Accept and SHOULD be sent unmodified by the client to
the accounting server as part of the Accounting-Request packet if
accounting is supported. The client MUST NOT interpret the
attribute locally.
A summary of the Class Attribute format is shown below. The fields
are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
25 for Class.
Length
>= 3
String
The String field is one or more octets. The actual format of the
information is site or application specific, and a robust
implementation SHOULD support the field as undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.26. Vendor-Specific
Description
This Attribute is available to allow vendors to support their own
extended Attributes not suitable for general usage. It MUST not
affect the operation of the RADIUS protocol.
Servers not equipped to interpret the vendor-specific information
sent by a client MUST ignore it (although it may be reported).
Clients which do not receive desired vendor-specific information
SHOULD make an attempt to operate without it, although they may do
so (and report they are doing so) in a degraded mode.
A summary of the Vendor-Specific Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Vendor-Id
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Vendor-Id (cont) | String...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
26 for Vendor-Specific.
Length
>= 7
Vendor-Id
The high-order octet is 0 and the low-order 3 octets are the SMI
Network Management Private Enterprise Code of the Vendor in
network byte order, as defined in the "Assigned Numbers" RFC[6].
String
The String field is one or more octets. The actual format of the
information is site or application specific, and a robust
implementation SHOULD support the field as undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
It SHOULD be encoded as a sequence of vendor type / vendor length
/ value fields, as follows. The Attribute-Specific field is
dependent on the vendor's definition of that attribute. An
example encoding of the Vendor-Specific attribute using this
method follows:
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Vendor-Id
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Vendor-Id (cont) | Vendor type | Vendor length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Attribute-Specific...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Multiple subattributes MAY be encoded within a single Vendor-
Specific attribute, although they do not have to be.
5.27. Session-Timeout
Description
This Attribute sets the maximum number of seconds of service to be
provided to the user before termination of the session or prompt.
This Attribute is available to be sent by the server to the client
in an Access-Accept or Access-Challenge.
A summary of the Session-Timeout Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
27 for Session-Timeout.
Length
6
Value
The field is 4 octets, containing a 32-bit unsigned integer with
the maximum number of seconds this user should be allowed to
remain connected by the NAS.
5.28. Idle-Timeout
Description
This Attribute sets the maximum number of consecutive seconds of
idle connection allowed to the user before termination of the
session or prompt. This Attribute is available to be sent by the
server to the client in an Access-Accept or Access-Challenge.
A summary of the Idle-Timeout Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
28 for Idle-Timeout.
Length
6
Value
The field is 4 octets, containing a 32-bit unsigned integer with
the maximum number of consecutive seconds of idle time this user
should be permitted before being disconnected by the NAS.
5.29. Termination-Action
Description
This Attribute indicates what action the NAS should take when the
specified service is completed. It is only used in Access-Accept
packets.
A summary of the Termination-Action Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
29 for Termination-Action.
Length
6
Value
The Value field is four octets.
0 Default
1 RADIUS-Request
If the Value is set to RADIUS-Request, upon termination of the
specified service the NAS MAY send a new Access-Request to the
RADIUS server, including the State attribute if any.
5.30. Called-Station-Id
Description
This Attribute allows the NAS to send in the Access-Request packet
the phone number that the user called, using Dialed Number
Identification (DNIS) or similar technology. Note that this may
be different from the phone number the call comes in on. It is
only used in Access-Request packets.
A summary of the Called-Station-Id Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
30 for Called-Station-Id.
Length
>= 3
String
The String field is one or more octets, containing the phone
number that the user's call came in on.
The actual format of the information is site or application
specific. UTF-8 encoded 10646 [7] characters are recommended, but
a robust implementation SHOULD support the field as
undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.31. Calling-Station-Id
Description
This Attribute allows the NAS to send in the Access-Request packet
the phone number that the call came from, using Automatic Number
Identification (ANI) or similar technology. It is only used in
Access-Request packets.
A summary of the Calling-Station-Id Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
31 for Calling-Station-Id.
Length
>= 3
String
The String field is one or more octets, containing the phone
number that the user placed the call from.
The actual format of the information is site or application
specific. UTF-8 encoded 10646 [7] characters are recommended, but
a robust implementation SHOULD support the field as
undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.32. NAS-Identifier
Description
This Attribute contains a string identifying the NAS originating
the Access-Request. It is only used in Access-Request packets.
Either NAS-IP-Address or NAS-Identifier MUST be present in an
Access-Request packet.
Note that NAS-Identifier MUST NOT be used to select the shared
secret used to authenticate the request. The source IP address of
the Access-Request packet MUST be used to select the shared
secret.
A summary of the NAS-Identifier Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
32 for NAS-Identifier.
Length
>= 3
String
The String field is one or more octets, and should be unique to
the NAS within the scope of the RADIUS server. For example, a
fully qualified domain name would be suitable as a NAS-Identifier.
The actual format of the information is site or application
specific, and a robust implementation SHOULD support the field as
undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.33. Proxy-State
Description
This Attribute is available to be sent by a proxy server to
another server when forwarding an Access-Request and MUST be
returned unmodified in the Access-Accept, Access-Reject or
Access-Challenge. When the proxy server receives the response to
its request, it MUST remove its own Proxy-State (the last Proxy-
State in the packet) before forwarding the response to the NAS.
If a Proxy-State Attribute is added to a packet when forwarding
the packet, the Proxy-State Attribute MUST be added after any
existing Proxy-State attributes.
The content of any Proxy-State other than the one added by the
current server should be treated as opaque octets and MUST NOT
affect operation of the protocol.
Usage of the Proxy-State Attribute is implementation dependent. A
description of its function is outside the scope of this
specification.
A summary of the Proxy-State Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
33 for Proxy-State.
Length
>= 3
String
The String field is one or more octets. The actual format of the
information is site or application specific, and a robust
implementation SHOULD support the field as undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.34. Login-LAT-Service
Description
This Attribute indicates the system with which the user is to be
connected by LAT. It MAY be used in Access-Accept packets, but
only when LAT is specified as the Login-Service. It MAY be used
in an Access-Request packet as a hint to the server, but the
server is not required to honor the hint.
Administrators use the service attribute when dealing with
clustered systems, such as a VAX or Alpha cluster. In such an
environment several different time sharing hosts share the same
resources (disks, printers, etc.), and administrators often
configure each to offer access (service) to each of the shared
resources. In this case, each host in the cluster advertises its
services through LAT broadcasts.
Sophisticated users often know which service providers (machines)
are faster and tend to use a node name when initiating a LAT
connection. Alternately, some administrators want particular
users to use certain machines as a primitive form of load
balancing (although LAT knows how to do load balancing itself).
A summary of the Login-LAT-Service Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
34 for Login-LAT-Service.
Length
>= 3
String
The String field is one or more octets, and contains the identity
of the LAT service to use. The LAT Architecture allows this
string to contain $ (dollar), - (hyphen), . (period), _
(underscore), numerics, upper and lower case alphabetics, and the
ISO Latin-1 character set extension [11]. All LAT string
comparisons are case insensitive.
5.35. Login-LAT-Node
Description
This Attribute indicates the Node with which the user is to be
automatically connected by LAT. It MAY be used in Access-Accept
packets, but only when LAT is specified as the Login-Service. It
MAY be used in an Access-Request packet as a hint to the server,
but the server is not required to honor the hint.
A summary of the Login-LAT-Node Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
35 for Login-LAT-Node.
Length
>= 3
String
The String field is one or more octets, and contains the identity
of the LAT Node to connect the user to. The LAT Architecture
allows this string to contain $ (dollar), - (hyphen), . (period),
_ (underscore), numerics, upper and lower case alphabetics, and
the ISO Latin-1 character set extension. All LAT string
comparisons are case insensitive.
5.36. Login-LAT-Group
Description
This Attribute contains a string identifying the LAT group codes
which this user is authorized to use. It MAY be used in Access-
Accept packets, but only when LAT is specified as the Login-
Service. It MAY be used in an Access-Request packet as a hint to
the server, but the server is not required to honor the hint.
LAT supports 256 different group codes, which LAT uses as a form
of access rights. LAT encodes the group codes as a 256 bit
bitmap.
Administrators can assign one or more of the group code bits at
the LAT service provider; it will only accept LAT connections that
have these group codes set in the bit map. The administrators
assign a bitmap of authorized group codes to each user; LAT gets
these from the operating system, and uses these in its requests to
the service providers.
A summary of the Login-LAT-Group Attribute format is shown below.
The fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
36 for Login-LAT-Group.
Length
34
String
The String field is a 32 octet bit map, most significant octet
first. A robust implementation SHOULD support the field as
undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.37. Framed-AppleTalk-Link
Description
This Attribute indicates the AppleTalk network number which should
be used for the serial link to the user, which is another
AppleTalk router. It is only used in Access-Accept packets. It
is never used when the user is not another router.
A summary of the Framed-AppleTalk-Link Attribute format is shown
below. The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
37 for Framed-AppleTalk-Link.
Length
6
Value
The Value field is four octets. Despite the size of the field,
values range from 0 to 65535. The special value of 0 indicates
that this is an unnumbered serial link. A value of 1-65535 means
that the serial line between the NAS and the user should be
assigned that value as an AppleTalk network number.
5.38. Framed-AppleTalk-Network
Description
This Attribute indicates the AppleTalk Network number which the
NAS should probe to allocate an AppleTalk node for the user. It
is only used in Access-Accept packets. It is never used when the
user is another router. Multiple instances of this Attribute
indicate that the NAS may probe using any of the network numbers
specified.
A summary of the Framed-AppleTalk-Network Attribute format is shown
below. The fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
38 for Framed-AppleTalk-Network.
Length
6
Value
The Value field is four octets. Despite the size of the field,
values range from 0 to 65535. The special value 0 indicates that
the NAS should assign a network for the user, using its default
cable range. A value between 1 and 65535 (inclusive) indicates
the AppleTalk Network the NAS should probe to find an address for
the user.
5.39. Framed-AppleTalk-Zone
Description
This Attribute indicates the AppleTalk Default Zone to be used for
this user. It is only used in Access-Accept packets. Multiple
instances of this attribute in the same packet are not allowed.
A summary of the Framed-AppleTalk-Zone Attribute format is shown
below. The fields are transmitted from left to right.
0 1 2
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
39 for Framed-AppleTalk-Zone.
Length
>= 3
String
The name of the Default AppleTalk Zone to be used for this user.
A robust implementation SHOULD support the field as
undistinguished octets.
The codification of the range of allowed usage of this field is
outside the scope of this specification.
5.40. CHAP-Challenge
Description
This Attribute contains the CHAP Challenge sent by the NAS to a
PPP Challenge-Handshake Authentication Protocol (CHAP) user. It
is only used in Access-Request packets.
If the CHAP challenge value is 16 octets long it MAY be placed in
the Request Authenticator field instead of using this attribute.
A summary of the CHAP-Challenge Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | String...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
60 for CHAP-Challenge.
Length
>= 7
String
The String field contains the CHAP Challenge.
5.41. NAS-Port-Type
Description
This Attribute indicates the type of the physical port of the NAS
which is authenticating the user. It can be used instead of or in
addition to the NAS-Port (5) attribute. It is only used in
Access-Request packets. Either NAS-Port (5) or NAS-Port-Type or
both SHOULD be present in an Access-Request packet, if the NAS
differentiates among its ports.
A summary of the NAS-Port-Type Attribute format is shown below. The
fields are transmitted from left to right.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
61 for NAS-Port-Type.
Length
6
Value
The Value field is four octets. "Virtual" refers to a connection
to the NAS via some transport protocol, instead of through a
physical port. For example, if a user telnetted into a NAS to
authenticate himself as an Outbound-User, the Access-Request might
include NAS-Port-Type = Virtual as a hint to the RADIUS server
that the user was not on a physical port.
0 Async
1 Sync
2 ISDN Sync
3 ISDN Async V.120
4 ISDN Async V.110