“TACACS+ provides access control for routers, network access servers and other networked computing devices via one or more centralized servers. TACACS+ provides separate authentication, authorization and accounting services.” –ietf draft-grant-tacacs-02
Configure TACACS:
switch(config)# tacacs-server host IP-ADDR [key <plain|cipher>text KEY]
Depending on the TACACS server, change the auth-type from PAP to CHAP:
switch(config)# tacacs-server auth-type [pap|chap]
Configure AAA:
switch(config)# aaa authentication login default group tacacs local
switch(config)# aaa authorization commands default group tacacs
switch(config)# aaa accounting all default start-stop group tacacs
Show commands to validate functionality:
show tacacs-server [detail]