Consider the following network. You are the network administrator, and you want to configure, on the router R$1,$ the centralized authentication using AAA and RADIUS. The RADIUS server is already

configured with one user RadUser with the password RadUserpass and the secret shared key StrongKey.

$1.$ Enable AAA on R$1$

in the terminal of R$1$ enable AAA

R$1($config$)$# $..$

$2.$Configure the default login authentication list.

Configure the list to first use RADIUS for the authentication service, and then the fallback, local database and enable, if no RADIUS server can be reached and authentication cannot be performed. This

is a safeguard measure in case the router starts up without connectivity to an active RADIUS server.

R$1($config$)$# $..$

$3.$ Specify a RADIUS server

a$.$use the radius server command to enter RADIUS server configuration mode. The name of the server is server$-$R

R$1($config$)$# $..$

b$.$configure the IP address of the RADIUS server. The ip address of the server is $192\mathrm{.}168\mathrm{.}1\mathrm{.}1/24$

R$1($config$-$radius$-$server$)$#$...$

c$.$ configure the key used for the secret password that is shared between the RADIUS server and the router $($R$1$ in this case$)$ and is used to authenticate the connection between the router and the server before the user authentication process takes place. use the secret password of StrongPass that has been configured on the Radius server.

R$1($config$-$radius$-$server$)$#$...$