Chapter 6 Deploying Wireless Networks for FortiOS 5.0 : Configuring a WiFi LAN : Defining a wireless network interface (SSID) : Configuring DHCP for WiFi clients
  
Configuring DHCP for WiFi clients
Wireless clients need to have IP addresses. If you use RADIUS authentication, each user’s IP address can be stored in the Framed-IP-Address attribute. Otherwise, you need to configure a DHCP server on the WLAN interface to assign IP addresses to wireless clients.
To configure a DHCP server for WiFi clients - web-based manager
1. Go to WiFi Controller > WiFi Network > SSID and edit your SSID entry.
2. In the WiFi Settings section, enable DHCP Server.
3. In Address Range, select Create New.
4. In the Starting IP and End IP fields, enter the IP address range to assign.
The address range needs to be in the same subnet as the wireless interface IP address, but not include that address.
5. Set the Netmask to an appropriate value, such as 255.255.255.0.
6. Set the Default Gateway to Same as Interface IP.
7. Set the DNS Server to Same as System DNS.
8. If you want to restrict access to the wireless network by MAC address, see “Adding a MAC filter”.
9. Select OK.
To configure a DHCP server for WiFi clients - CLI
In this example, WiFi clients on the example_wlan interface are assigned addresses in the 10.10.120.2-9 range to connect with the WiFi access point on 10.10.120.1.
config system dhcp server
edit 0
set default-gateway 10.10.120.1
set dns-service default
set interface example_wlan
set netmask 255.255.255.0
config ip-range
edit 1
set end-ip 10.10.120.9
set start-ip 10.10.120.2
end
end
 
You cannot delete an SSID (wireless interface) that has DHCP enabled on it.