Cisco Certified Internetwork Expert (CCIE) 2025 – 400 Free Practice Questions to Pass the Exam

The correct choice highlights that the local database on a router configured for TACACS+ serves as a backup method for authentication. When TACACS+ is operational, the primary method for authenticating users is through the TACACS+ server. However, if there are issues with connectivity to the TACACS+ server or if the server is unavailable, the router will then resort to the local database to authenticate users. This ensures continuous access and redundancy in authentication processes.

Understanding this is crucial, as it emphasizes the importance of having a local database as a fallback mechanism. In environments reliant on centralized authentication systems like TACACS+, having a local auth option ensures that administrators can still gain access to devices during server outages or network issues without total lockout.

The other choices do not accurately portray the role of the local database. For instance, while the local database does define user access levels, that is not its sole function or a comprehensive overview of its purpose. It also does not serve as the primary authentication method when TACACS+ is being used. Furthermore, when TACACS+ is active, the local database is indeed consulted primarily as a fallback rather than completely ignored. This understanding is critical for maintaining effective network management and security practices.