HP MSR Series Configuration Manual page 19

Figure 4 RADIUS packet format
Descriptions of the fields are as follows:
•
The Code field (1 byte long) indicates the type of the RADIUS packet.
values and their meanings.
Table 1 Main values of the Code field
Code Packet type
1 Access-Request
2 Access-Accept
3 Access-Reject
Accounting-Reques
4
t
Accounting-Respon
5
se
•
The Identifier field (1 byte long) is used to match response packets with request packets and to
detect duplicate request packets. The request and response packets of the same exchange
process for the same purpose (such as authentication or accounting) have the same identifier.
•
The Length field (2 bytes long) indicates the length of the entire packet (in bytes), including the
Code, Identifier, Length, Authenticator, and Attributes fields. Bytes beyond this length are
considered padding and are ignored by the receiver. If the length of a received packet is less
than this length, the packet is dropped.
•
The Authenticator field (16 bytes long) is used to authenticate responses from the RADIUS
server and to encrypt user passwords. There are two types of authenticators: request
authenticator and response authenticator.
•
The Attributes field (variable in length) includes authentication, authorization, and accounting
information. This field can contain multiple attributes, each with the following subfields:
Description
From the client to the server. A packet of this type includes user
information for the server to authenticate the user. It must contain the
User-Name attribute and can optionally contain the attributes of
NAS-IP-Address, User-Password, and NAS-Port.
From the server to the client. If all attribute values included in the
Access-Request are acceptable, the authentication succeeds, and
the server sends an Access-Accept response.
From the server to the client. If any attribute value included in the
Access-Request is unacceptable, the authentication fails, and the
server sends an Access-Reject response.
From the client to the server. A packet of this type includes user
information for the server to start or stop accounting for the user. The
Acct-Status-Type attribute in the packet indicates whether to start or
stop accounting.
From the server to the client. The server sends a packet of this type to
notify the client that it has received the Accounting-Request and has
successfully recorded the accounting information.
4
Table 1 gives the main