TACACS+ (Terminal Access Controller Access Control System Plus) is a security protocol that can be used as an alternative to the standard RADIUS security protocol. The client function is implemented on the S- K- or 7100-Series device to control access to this device in conjunction with a remote server. TACACS is defined in RFC 1492, and TACACS+ is defined in an un-published and expired Internet Draft draft-grant-tacacs-02.txt, “The TACACS+ Protocol Version 1.78", January, 1997.
TACACS+ client functionality falls into four basic capabilities: authentication and session authorization, per-command authorization, session accounting, and per-command accounting.
When the single connect feature is enabled, the TACACS+ client will use a single TCP connection for all requests to a given TACACS+ server.