H3C Technologies H3C SecBlade LB Cards - Manual (Page 51)

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Figure 23 RADIUS packet format
Descriptions of the fields are as follows:
• The Code field (1 byte long) indicates the type of the RADIUS packet.
Table 9 Main values of the Code field
Code Packet type Description
1 Access-Request
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.
2 Access-Accept
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.
3 Access-Reject
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.
4 Accounting-Request
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.
5 Accounting-Response
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.
• 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 Attributes fields. Bytes beyond this length are considered
padding and are ignored at the receiver. 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.
• 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) carries the specific authentication, authorization, and
accounting information that defines the configuration details of the request or response. This field
may contain multiple attributes, each with three sub-fields:
Code
Attributes
Identifier
0
7
Length
Authenticator
7 15 31