Understanding Radius; Radius Operation - Cisco Aironet 1100 Series Installation And Configuration Manual

Understanding RADIUS

Understanding RADIUS
RADIUS is a distributed client/server system that secures networks against unauthorized access.
RADIUS clients run on supported Cisco devices and send authentication requests to a central RADIUS
server, which contains all user authentication and network service access information. The RADIUS host
is normally a multiuser system running RADIUS server software from Cisco (Cisco Secure Access
Control Server version 3.0), Livingston, Merit, Microsoft, or another software provider. For more
information, refer to the RADIUS server documentation.
Use RADIUS in these network environments, which require access security:
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RADIUS is not suitable in these network security situations:
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RADIUS Operation

When a wireless user attempts to log in and authenticate to an access point that is access controlled by
a RADIUS server, authentication to the network occurs in the steps shown in
Cisco Aironet 1100 Series Access Point Installation and Configuration Guide
11-2
Networks with multiple-vendor access servers, each supporting RADIUS. For example, access
servers from several vendors use a single RADIUS server-based security database. In an IP-based
network with multiple vendors' access servers, dial-in users are authenticated through a RADIUS
server that is customized to work with the Kerberos security system.
Turnkey network security environments in which applications support the RADIUS protocol, such
as in an access environment that uses a smart card access control system. In one case, RADIUS has
been used with Enigma's security cards to validate users and to grant access to network resources.
Networks already using RADIUS. You can add a Cisco access point containing a RADIUS client to
the network.
Networks that require resource accounting. You can use RADIUS accounting independently of
RADIUS authentication or authorization. The RADIUS accounting functions allow data to be sent
at the start and end of services, showing the amount of resources (such as time, packets, bytes, and
so forth) used during the session. An Internet service provider might use a freeware-based version
of RADIUS access control and accounting software to meet special security and billing needs.
Multiprotocol access environments. RADIUS does not support AppleTalk Remote Access (ARA),
NetBIOS Frame Control Protocol (NBFCP), NetWare Asynchronous Services Interface (NASI), or
X.25 PAD connections.
Switch-to-switch or router-to-router situations. RADIUS does not provide two-way authentication.
RADIUS can be used to authenticate from one device to a non-Cisco device if the non-Cisco device
requires authentication.
Networks using a variety of services. RADIUS generally binds a user to one service model.
Chapter 11 Configuring RADIUS Servers
Figure 11-1:
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