terminal access controller access control system (TACACS)

Terminal Access Controller Access Control System(TACACS+ is a security protocol for authenticatingclients of a client- server architecture.

TACACS supports remote access authentication and similar services via a remote access server( RAS) or AAA server, in which the authentication data is stored. User passwords are managed in a central database, enabling simple, scalable solutions. TACACS servers provide authentication credentials to users so they can establish an IP connection to a Network Access Server( NAS). All communication is encrypted.

TACACS is Internet Engineering Task Force( IETF) standardized protocol, functionally similar to RADIUS described in RFC 1492 from 1993. In contrast to the Radius protocol, TACACS works with the connection-oriented TCP protocol. An extension of TACACS is formed by Extended TACACS (XTACACS) and TACACS+ , developed by Cisco, which uses a more detailed authentication protocol.