3Com Switch 7750 Configuration Guide

Overview 515
The basic message exchange procedure is as follows:
1 A user requests access to the switch; the TACACS client sends an authentication
start request packet to TACACS server upon receipt of the request.
2 The TACACS server sends back an authentication response requesting for the
username; the TACACS client asks the user for the username upon receipt of the
response.
3 The TACACS client sends an authentication continuance packet carrying the
username after receiving the username from the user.
4 The TACACS server sends back an authentication response, requesting for the
password. Upon receipt of the response, the TACACS client requests the user for
the login password.
5 After receiving the login password, the TACACS client sends an authentication
continuance packet carrying the login password to the TACACS server.
6 The TACACS server sends back an authentication response indicating that the user
has passed the authentication.
7 The TACACS client sends the user authorization request packet to the TACACS
server.
8 The TACACS server sends back the authorization response, indicating that the user
has passed the authorization.
9 Upon receipt of the response indicating an authorization success, the TACACS
client pushes the configuration interface of the switch to the user.
10 The TACACS client sends an accounting start request packet to the TACACS
server.
11 The TACACS server sends back an accounting response, indicating that it has
received the accounting start request.
12 The user logs out; the TACACS client sends an accounting stop request to the
TACACS server.
13 The TACACS server sends back an accounting stop packet, indicating that the
accounting stop request has been received.