Radius Packet Format - HP 830 Series Configuration Manual

RADIUS packet format

RADIUS uses UDP to transmit messages. To ensure smooth message exchange between the RADIUS
server and the client, RADIUS uses a timer management mechanism, a retransmission mechanism, and
a backup server mechanism.
Figure 419 RADIUS packet format
0
Code
The following describes the fields of a RADIUS packet:
The Code field (1 byte long) indicates the type of the RADIUS packet.
•
Table 119 Main values of the Code field
Code Packet type
1 Access-Request
2 Access-Accept
3 Access-Reject
4 Accounting-Request
5 Accounting-Response
The Identifier field (1 byte long) is used to match request packets and response packets and to detect
•
duplicate request packets. Request and response packets of the same type have the same identifier.
The Length field (2 bytes long) indicates the length of the entire packet, including the Code,
•
Identifier, Length, Authenticator, and Attribute fields. Bytes beyond this length are considered
padding and are not used. If the length of a received packet is less than this length, the packet is
dropped. The value of this field is in the range 20 to 4096.
Figure 419 shows the RADIUS packet format.
7 15
Identifier
Authenticator
Attributes
Description
From the client to the server. A packet of this type carries 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 carried 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 carried 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 carries 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.
7
Length
404
31