TACACS+ Authentication 
Configuring TACACS+ on the Switch 
Table 5-2.  Primary/Secondary Authentication Table 
Access Method and  Authentication Options  Effect on Access Attempts 
Privilege Level 
Primary  Secondary 
Console — Login 
Console — Enable 
Telnet — Login 
Telnet — Enable 
local 
tacacs 
local 
tacacs 
local 
tacacs 
tacacs 
local 
tacacs 
tacacs 
none*  Local username/password access only. 
local  If Tacacs+ server unavailable, uses local username/password access. 
none*  Local username/password access only. 
local  If Tacacs+ server unavailable, uses local username/password access. 
none*  Local username/password access only. 
local  If Tacacs+ server unavailable, uses local username/password access. 
none  If Tacacs+ server unavailable, denies access. 
none*  Local username/password access only. 
local  If Tacacs+ server unavailable, uses local username/password access. 
none  If Tacacs+ server unavailable, denies access. 
*When “local” is the primary option, you can also select “local” as the secondary option. However, in this case, a 
secondary “local” is meaningless because the switch has only one local level of username/password protection. 
Caution Regarding 
the Use of Local for 
Login Primary 
Access 
During local authentication (which uses passwords configured in the switch 
instead of in a TACACS+ server), the switch grants read-only access if you 
enter the Operator password, and read-write access if you enter the Manager 
password. For example, if you configure authentication on the switch with 
Telnet Login Primary as Local and Telnet Enable Primary as Tacacs, when you 
attempt to Telnet to the switch, you will be prompted for a local password. If 
you enter the switch’s local Manager password (or, if there is no local Manager 
password configured in the switch) you can bypass the TACACS+ server 
authentication for Telnet Enable Primary and go directly to read-write (Man
-
ager) access. Thus, for either the Telnet or console access method, configuring 
Login Primary for Local authentication while configuring Enable Primary for 
TACACS+ authentication is not recommended, as it defeats the purpose of 
using the TACACS+ authentication. If you want Enable Primary log-in 
attempts to go to a TACACS+ server, then you should configure both Login 
Primary and Enable Primary for Tacacs authentication instead of configuring 
Login Primary to Local authentication. 
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