thanks guys, from the sites that you have given i started the acs configuration, that works fine. But whenever i use enable i got an error message like Authentication failed.
My configuration goes like this
aaa new-model
aaa authentication login telnet_lines group tacacs+
aaa authentication enable default group tacacs+ enable----------when i use this command i got AUTHENTICATION FAILED
enable password cisco
aaa session-id common
tacacs-server host 172.17.11.19 key cisco
line vty 0 4
authorization commands 15 telnet_lines
authorization exec telnet_lines
login authentication telnet_lines
guys, I am using ACS 5.0. What should i do with this?
thanks