Operation Manual – AAA&RADIUS
Quidway S3100 Series Ethernet Switches
Chapter 1 AAA&RADIUS Configuration
Huawei Technologies Proprietary
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III. RADIUS packet structure
RADIUS uses UDP to transmit messages. It ensures the correct message exchange
between RADIUS server and client through the following mechanisms: timer
management, retransmission, and backup server. Figure 1-3 depicts the structure of
the RADIUS packets.
Code
Identifier
Length
Authenticator
Attribute
Figure 1-3
RADIUS packet structure
1)
The Code field decides the type of the RADIUS packet, as shown in Table 1-1.
Table 1-1
Description on major values of the Code field
Code
Packet type
Packet description
1 Access-Request
Direction: client->server.
The client transmits this packet to the server to
determine if the user can access the network.
This packet carries user information. It must contain the
User-Name attribute and may contain the following
attributes: NAS-IP-Address, User-Password and
NAS-Port.
2 Access-Accept
Direction: server->client.
The server transmits this packet to the client if all the
attribute values carried in the Access-Request packet
are acceptable (that is, the user passes the
authentication).
3 Access-Reject
Direction: server->client.
The server transmits this packet to the client if any
attribute value carried in the Access-Request packet is
unacceptable (that is, the user fails the authentication).
4
Accounting-Req
uest
Direction: client->server.
The client transmits this packet to the server to request
the server to start or end the accounting (whether to
start or to end the accounting is determined by the
Acct-Status-Type attribute in the packet).
This packet carries almost the same attributes as those
carried in the Access-Request packet.
