# Configuring AAA

AAA stands for **Authentication, Authorization and Accounting**. These protocols were defined by the Internet Engineering Task Force and are intended to provide an Authentication, Authorization, and Accounting (AAA) framework for applications, such as network access or IP mobility in both local and roaming situations.

TACACS uses (either TCP or UDP) port 49 by default. TACACS allows a client to accept a username and password and send a query to a TACACS authentication server, sometimes called a TACACS daemon or simply TACACSD. It would determine whether to accept or deny the authentication request and send a response back. In this way, the process of making the decision is "opened up" and the algorithms and data used to make the decision are under the complete control of the TACACS daemon.

RADIUS, which stands for Remote Authentication Dial-In User Service, is a network protocol commonly used for centralized authentication, authorization, and accounting (AAA) management. Similar to TACACS, RADIUS is designed to allow clients to authenticate and request services from a centralized server, referred to as a RADIUS server or RADIUS daemon.

{% content-ref url="configuring-aaa/configuring-aaa" %}
[configuring-aaa](https://aviznetworks.gitbook.io/opbnos-r2.7/cli-configuration-guide/configuring-aaa/configuring-aaa)
{% endcontent-ref %}

{% content-ref url="configuring-aaa/configuring-tacacs" %}
[configuring-tacacs](https://aviznetworks.gitbook.io/opbnos-r2.7/cli-configuration-guide/configuring-aaa/configuring-tacacs)
{% endcontent-ref %}

{% content-ref url="configuring-aaa/configuring-radius" %}
[configuring-radius](https://aviznetworks.gitbook.io/opbnos-r2.7/cli-configuration-guide/configuring-aaa/configuring-radius)
{% endcontent-ref %}
