Basic Radius Message Exchange Process - HP 1910 User Manual

security mechanism improves the security of RADIUS communication and prevents user passwords from
being intercepted on insecure networks.
A RADIUS server supports multiple user authentication methods. A RADIUS server can also act as the
client of another AAA server to provide authentication proxy services.

Basic RADIUS message exchange process

Figure 398 illustrates the interactions between the host, the RADIUS client, and the RADIUS server.
Figure 398 Basic RADIUS message exchange process
RADIUS operates in the following manner:
The host initiates a connection request that carries the user's username and password to the
1.
RADIUS client.
Having received the username and password, the RADIUS client sends an authentication request
2.
(Access-Request) to the RADIUS server, with the user password encrypted by using the
Message-Digest 5 (MD5) algorithm and the shared key.
The RADIUS server authenticates the username and password. If the authentication succeeds, the
3.
server sends back an Access-Accept message containing the user's authorization information. If
the authentication fails, the server returns an Access-Reject message.
The RADIUS client permits or denies the user according to the returned authentication result. If it
4.
permits the user, it sends a start-accounting request (Accounting-Request) to the RADIUS server.
The RADIUS server returns an acknowledgement (Accounting-Response) and starts accounting.
5.
The user accesses the network resources.
6.
The host requests the RADIUS client to tear down the connection and the RADIUS client sends a
7.
stop-accounting request (Accounting-Request) to the RADIUS server.
The RADIUS server returns an acknowledgement (Accounting-Response) and stops accounting for
8.
the user.
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