Force AAA to use the IP address of a specified interface for all outgoing AAA packets Rationale: This is required so that the AAA server (RADIUS or TACACS+) can easily identify routers and authenticate requests by their IP address. Impact: Organizations should design and implement authentication, authorization, and accounting (AAA) services for effective monitoring of enterprise network devices. Binding AAA services to the source-interface loopback enables these services.
Solution
Bind AAA services to the loopback interface. Hostname(config)#ip radius source-interface loopback {loopback_interface_number} or Hostname(config)#aaa group server tacacs+ {group_name} hostname(config-sg-tacacs+)#ip tacacs source-interface {loopback_interface_number}