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.
RADIUS SSO topology
Configuring RADIUS
Configuring RADIUS includes configuring the RADIUS server such as FreeRADIUS, a radius client on user’s computers, and configuring users in the system. For this example the two users will be Pat Lee, and Kelly Green. They belong to a group called exampledotcom_employees. When it is all configured, the RADIUS daemon needs to started.
The users have a RADIUS client installed on their PCs that allows them to authenticate through the RADIUS server.
FreeRADIUS can be found on the freeradius.org website. For any problems installing FreeRADIUS, see the FreeRADIUS documentation.
Configuring FortiGate interfaces
Before configuring the RADIUS SSO security policy, configure FortiGate interfaces. This includes defining a DHCP server for the internal network as this type of network typically uses DHCP. The wan1 and dmz interfaces are assigned static IP addresses and do not need a DHCP server.
FortiGate interfaces used in this example
| Interface | Subnet | Act as DHCP Server | Devices |
|
wan1 |
172.20.120.141 |
No |
Internet Service Provider |
dmz 10.11.101.100 No Servers, including RADIUS server
internal 10.11.102.100 Yes: x.x.x.110-.250 Internal user network
To configure FortiGate interfaces – web-based manager:
1. Go to System > Network > Interfaces.
2. Select wan1 to edit.
3. Enter the following information and select OK.
Alias Internet
Addressing Mode Manual
IP/Network Mask 172.20.120.141/255.255.255.0
Administrative Access HTTPS, SSH
Enable DHCP Server Not selected
Comments Internet
Administrative Status Up
4. Select dmz to edit.
5. Enter the following information and select OK.
Alias Servers
Addressing Mode Manual
IP/Network Mask 10.11.101.100/255.255.255.0
Administrative Access HTTPS, SSH, PING, SNMP
Enable DHCP Server Not selected
Listen for RADIUS Account- ing Messages Select
Comments Servers
Administrative Status Up
6. Select internal to edit.
7. Enter the following information and select OK.
Alias Internal network
Addressing Mode Manual
IP/Network Mask 10.11.102.100/255.255.255.0
Administrative Access HTTPS, SSH, PING
Enable DHCP Server Select
Address Range 10.11.102.110 – 10.11.102.250
Netmask 255.255.255.0
Default Gateway Same as Interface IP
DNS Server Same as System DNS
Comments Internal network
Administrative Status Up
Configuring a RADIUS SSO Agent on the FortiGate unit
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