Cisco AAA

Authentication, Authorization and Accounting (AAA) may be configured to use Cisco ACS server, which supports two protocols: Cisco proprietary TACACS+ and open standard RADIUS. The first one is more suitable for granular CLI commands authorization control, the second one provides better accounting. TACACS+ encrypts the entire messages between a network switch and ACS, RADIUS - only passwords. ACS does not have to have a local user database. It may use existing one such as Active Directory, for example.

 config# aaa new-model
 config# aaa authentication login <auth_name> group tacacs+ local
 config# aaa authorization exec <author_name> group tacacs+ local
 config# username <user> priviledge 15 secret <password>
 config# tacacs-server host <ip> key <password>
 config# line vty 0 4
 config-line# login authentication <auth_name>
 config-line# authorization exec <author_name>
 config-line# end
 # debug tacacs
 # debug aaa authentication
 # debug aaa authorization
 # test aaa group tacacs+ <user> <password> legacy