4-8CHAPTER 4: S YSTEM CONFIGURATIONRADIUS Remote Authentication Dial-in User Service (RADIUS) is an authentication protocolthat uses software running on a central server to control access to RADIUS-awaredevices on the network. An authentication server contains a database of usercredentials for each user that requires access to the network.A primary RADIUS server must be specified for the access point to implement IEEE802.1X network access control and Wi-Fi Protected Access (WPA) wirelesssecurity. A secondary RADIUS server may also be specified as a backup should theprimary server fail or become inaccessible.In addition, the configured RADIUS server can also act as a RADIUS Accountingserver and receive user-session accounting information from the access point.RADIUS Accounting can be used to provide valuable information on user activityin the network.Figure 22 RADIUS AuthenticationPrimary RADIUS Server Setup – Configure the following settings to use RADIUSauthentication on the access point. IP Address: Specifies the IP address or host name of the RADIUS server.NOTE: This guide assumes that you have already configured RADIUS server(s) tosupport the access point. Configuration of RADIUS server software is beyond thescope of this guide, refer to the documentation provided with the RADIUS serversoftware.