Hi,
I think the below link shall help you.
http://networklessons.com/linux/how-to-install-tacacs-on-linux-centos/
If you need configuration example for routers or switches, let me know.
Below is document if you have ACS and you need to integrate it with AD.
http://www.cisco.com/c/en/us/support/docs/security/secure-access-control-system/113571-acs5-ad-int-config-00.html
Regards,
Kanwal
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