Cisco Certified Network Professional Practice Test 2025 – Your All-in-One Guide to Exam Success!

In the AAA model, which stands for Authentication, Authorization, and Accounting, local or line authentication is often considered a last resort. This approach is utilized when all other methods of authentication, such as TACACS+ or RADIUS, are unavailable or fail to authenticate a user. Local authentication refers to using locally stored credentials, such as a username and password configured directly on the network device itself.

This method is particularly useful in situations where network access methods are compromised or when external authentication servers are not reachable due to network issues. By relying on local authentication, network devices can still maintain a level of security and accessibility for administrators. Local users must be carefully managed since their credentials reside on the device, and employing this method might limit the scalability and centralized management that TACACS+ and RADIUS offer.

It is important to note that while other methods provide centralized control and better management of user credentials, the local authentication serves as a reliable fallback, ensuring that access can still be granted even when network services are down.