TACACS+
Terminal Access Controller Access Control System Plus
A Cisco AAA protocol that separates authentication, authorization, and accounting.
TACACS+ is a Cisco developed AAA protocol used mainly for administering network devices, separating authentication, authorization, and accounting into independent functions for granular command level control. Unlike RADIUS, it encrypts the entire packet payload rather than only the password and runs over TCP for reliable delivery. This makes it well suited to device administration where per command authorization matters. The exam frequently contrasts TACACS+ with RADIUS, which is UDP based, encrypts only the password, and is favored for network access authentication.
Cisco AAA that Takes Apart the three As (separate authentication, authorization, accounting), runs over TCP, and encrypts the whole packet. The "+" means full-payload encryption.
Looking TACACS+ up is step one. Getting tested on it is step two.
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