TACACS (Terminal Access Controller Access Control System) is an older authentication protocol common to UNIX networks that allows a remote access server to forward a user's logon password to an authentication server to determine whether access can be allowed to a given system. TACACS is an encryption protocol and therefore less secure than the later TACACS+ and Remote Authentication Dial-In User Service protocols. A later version of TACACS is XTACACS (Extended TACACS). Both are described in Request for Comments 1492.
By submitting your email address, you agree to receive emails regarding relevant topic offers from TechTarget and its partners. You can withdraw your consent at any time. Contact TechTarget at 275 Grove Street, Newton, MA.
In spite of its name, TACACS+ is an entirely new protocol. TACACS+ and RADIUS have generally replaced the earlier protocols in more recently built or updated networks. TACACS+ uses the Transmission Control Protocol (TCP) and RADIUS uses the User Datagram Protocol (UDP). Some administrators recommend using TACACS+ because TCP is seen as a more reliable protocol. Whereas RADIUS combines authentication and authorization in a user profile, TACACS+ separates the two operations.
TACACS and XTACACS are still running on many older systems.
Continue Reading About TACACS (Terminal Access Controller Access Control System)
- In 1997, Cisco declared that TACACS and XTACACS are End-of-Maintenance (that is, problems would no longer be fixed by Cisco because newer protocols had replaced them).