User's Manual
10-13
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 10 Configuring Switch-Based Authentication
Controlling Switch Access with TACACS+
  • Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services, 
page 10-16
  • Starting TACACS+ Accounting, page 10-17
Default TACACS+ Configuration
TACACS+ and AAA are disabled by default.
To prevent a lapse in security, you cannot conf
igure TACACS+ through a network management 
application. When enabled, TACACS+ can authenticate users accessing the switch through the CLI.
Note Although TACACS+ configuration is performed through the CLI, the TACACS+ server authenticates 
HTTP connections that have been configured with a privilege level of 15.
Identifying the TACACS+ Server Host and Setting the Authentication Key
You can configure the switch to use a single server or AAA server groups to group existing server hosts 
for authentication. You can group servers to select a subset of the configured server hosts and use them 
for a particular service. The server group is used with a global server-host list and contains the list of IP 
addresses of the selected server hosts.
Beginning in privileged EXEC mode, follow these steps to identify the IP host or host maintaining 
T
ACACS+ server and optionally set the encryption key:
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
tacacs-server host hostname [port 
integer] [timeout integer] [key string]
Identify the IP host or hosts maintaining a TACACS+ server. Enter this 
command multiple times to create a list of preferred hosts. The software 
searches for hosts in the order in which you specify them.
  • For hostname, specify the name or IP address of the host.
  • (Optional) For port integer, specify a server port number. The default 
is port 49. The range is 1 to 65535.
  • (Optional) For timeout integer, specify a time in seconds the switch 
waits for a response from the daemon before it times out and declares 
an error. The default is 5 seconds. The range is 1 to 1000 seconds.
  • (Optional) For key string, specify the encryption key for encrypting 
and decrypting all traffic between the switch and the TACACS+ 
daemon. You must configure the same key on the TACACS+ daemon 
for encryption to be successful.
Step 3
aaa new-model Enable AAA.
Step 4
aaa group server tacacs+ group-name (Optional) Define the AAA server-group with a group name.
This command puts the switch in a server group subconfiguration mode.
Step 5
server ip-address  (Optional) Associate a particular TACACS+ server with the defined server 
group. Repeat this step for each TACACS+ server in the AAA server 
group.
Each server in the group must be previously defined in Step 2.










