Well, if you are new to fact that Cisco routers can communicate with Radius servers; then that most likely means, you are new to the Cisco IOS "Global" configuration command called "aaa new-model".

Network administrators (like you) use the "aaa new-model" command to enable the Authentication, Authorization, and Accounting (AAA) access control model on a Cisco router. In other words, the "aaa new-model" command is used to "Globally" enable a Cisco router for Authentication, Authorization, and Accounting or AAA.

Below is an example of using the command:

Example:

Router>enable

Router#configure terminal

Router(config)#aaa new-model

Router(config)#end

Router#

As you can see, it's a very simple command to use; because it doesn't require the use of arguments or keywords.

Now, let's say you've already used the "aaa new-model" command to enable Authentication, Authorization, and Accounting (AAA) on a Cisco router and now you want to disable it; well, to perform that task, all you need to do is type the word "no" in front of the command like you see below.

Syntax: Router(config)#no aaa new-model

And, just in case if you were wondering, Cisco routers by default are not enabled for Authentication, Authorization, and Accounting (AAA), you have to enable them.

I hope this article was very informative and helped you quickly understand the usage of the "aaa new-model"command. If you need to learn more about the command; I suggest you visit my website, were you'll find the latest information regarding Cisco IPv6 Design and Implementation Techniques.