TACACS+ Authentication 
Configuring TACACS+ on the Switch 
Note on 
Encryption Keys 
Syntax:  tacacs-server host < ip-addr > [key < key-string >] 
Adds a TACACS+ server and optionally assigns a server-specific 
encryption key
. 
[no] tacacs-server host < ip-addr > 
Removes a TACACS+ server assignment (including its server-
specific encryption key, if any)
. 
tacacs-server key <key-string> 
Enters the optional global encryption key. 
[no] tacacs-server key 
Removes the optional global encryption key. (Does not affect any 
server-specific encryption key assignments.) 
tacacs-server timeout < 1-255 > 
Changes the wait period for a TACACS server response. (Default: 
5 seconds.) 
Encryption keys configured in the switch must exactly match the encryption 
keys configured in TACACS+ servers the switch will attempt to use for 
authentication. 
If you configure a global encryption key, the switch uses it only with servers 
for which you have not also configured a server-specific key. Thus, a global 
key is more useful where the TACACS+ servers you are using all have an 
identical key, and server-specific keys are necessary where different 
TACACS+ servers have different keys. 
If TACACS+ server “X” does not have an encryption key assigned for the 
switch, then configuring either a global encryption key or a server-specific key 
in the switch for server “X” will block authentication support from server “X”. 
5-16