Chapter 3 Authentication for FortiOS 5.0 : Examples and Troubleshooting : RADIUS SSO example : Topology
  
Topology
Example.com has an office with 20 users on the internal network. These users need access to the Internet to do their jobs. The office network is protected by a FortiGate-60C unit with access to the Internet through the wan1 interface, the user network on the internal interface, and all the servers are on the DMZ interface. This includes an Ubuntu Linux server running FreeRADIUS. For this example only two users will be configured — Pat Lee with an account name plee, or plee@example.com, and Kelly Green with an account name kgreen, or kgreen@example.com.
Figure 130: RADIUS SSO topology