Terms
- RADIUS - Remote Authentication Dial-In User Service. Created to provide AAA for ISP users, or Dial-In for businesses.
- TACACS - Terminal Access Controller Access-Control System. An AAA protocol to provide support for authenticate once, authorize many.
- TACACS+ - Same as above, basically an upgraded version, not backward compatible.
- EAP - Extensible Authentication Protocol, 802.1x, used for LAN Auth, only works with RADIUS.
TACACS+ Flows
Authentication Flow

Authorization and Accouting Flow
