AAA/RADIUS/HWTACACS Overview 755
Basic message exchange process of HWTACACS
The following takes Telnet user as an example to describe how HWTACACS 
performs user authentication, authorization, and accounting. Figure 232 illustrates 
the basic message exchange process of HWTACACS.
Figure 232   Basic message exchange process of HWTACACS for a Telnet user
 
1 A Telnet user applies to access the NAS.
2 Upon receiving the request, the HWTACACS client sends a start-authentication 
packet to the HWTACACS server.
3 The HWTACACS server sends back an authentication response requesting the 
username.
4 Upon receiving the request, the HWTACACS client asks the user for the username.
5 The user enters the username.
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