Also known as: Authentication Authorization Accounting
Quick Definition
Authentication, Authorisation, and Accounting — the three-component framework for controlling network access.
AAA is a security framework for controlling access to network resources: Authentication (verifying identity — who are you?), Authorisation (determining what you can do — what are you allowed to?), and Accounting (tracking what you did — what did you do?). Cisco implements AAA through local methods (username/password on device) or centralised servers using RADIUS or TACACS+.
TACACS+ encrypts the entire authentication payload (more secure). RADIUS only encrypts the password. TACACS+ uses TCP port 49. RADIUS uses UDP ports 1812 (authentication) and 1813 (accounting).
AAA is a security framework for controlling access to network resources: Authentication (verifying identity — who are you?), Authorisation (determining what you can do — what are you allowed to?), and Accounting (tracking what you did — what did you do?). Cisco implements AAA through local methods (username/password on device) or centralised servers using RADIUS or TACACS+.
TACACS+ encrypts the entire authentication payload (more secure). RADIUS only encrypts the password. TACACS+ uses TCP port 49. RADIUS uses UDP ports 1812 (authentication) and 1813 (accounting).
AAA falls under the Security domain of the 200-301 exam. Understanding it in context with related terms like radius and tacacs-plus is essential for answering scenario-based questions correctly.