Configuring the Controller-Based DHCP Server
In FortiWLC (SD) release 5.1 and later, users have the ability to configure a DHCP server that can be operated directly from the controller. This configuration is ideal for relatively small
AP Groups
deployments that do not require a separate server to handle DHCP duties. This can be particularly useful for deployments that require a DHCP sever for a separate VLAN (such as one used for a guest network) but also would prefer not to allow that traffic to impact the corporate DHCP server.
The internal DHCP server does not support using Option 43 for multiple subnets. Use an external DHCP sever that supports Option 43 for multiple subnets.
The controller-based DHCP server requires that the DHCP Relay Passthrough option (in the Global Controller Parameters) be set to On for the controller. To verify or adjust this, access the WebUI and navigate to Configuration > Devices > Controller.
It is recommended that you do not user internal DHCP server in an enterprise deployment.
Creating a DHCP Server
The controller can have multiple different DHCP servers configured on it at any given time. A DHCP server can be associated to only one VLAN. The steps below can be repeated in order to configure different DHCP servers for separate VLANs or Virtual Interface Profiles as needed.
To create a DHCP Server:
- From the WebUI, navigate to Configuration > DHCP and click the DHCP Server tab to view the current configured DHCP servers. Note that if no servers have been configured, the page will be blank.
- Click Add to begin configuring the DHCP server parameters.
Figure 11: DHCP Server Configuration
- Provide the necessary information as described in Table 8.
Configuring the Controller-Based DHCP Server
TABLE 8: DHCP Options
| Option | Description |
| DHCP Server Pool
Name |
Enter a name to be ascribed to the DHCP Server. |
| VLAN Name | This drop-down list allows you to select a VLAN to which the server should be applied. Note that this is only available if the controller is operating in Layer 2 routing mode. |
| State | Set to Enabled in order to activate the DHCP server, Disabled to deactivate it. |
| Lease Time | The duration of IP leases that are assigned by the DHCP server. This value is displayed in seconds. |
| IP Pool Start/End | The start and end IP addresses of the IP pool that may be assigned by the DHCP server. |
| Domain Name | The domain on which the DHCP server will be active. |
| Primary/Secondary DNS Server | The primary and secondary DNS servers to be used by the DHCP server. |
| Primary/Secondary Netbios Server | The primary and secondary Netbios servers to be used by the DHCP server. |
| DHCP Option 43 | Option 43 allows you to manually specify the primary and secondary controllers to be used by the server. Enter the primary and secondary controller IP addresses (separated by a comma) in this field. |
- Click OK to save the server.
Viewing DHCP Leases
After the DHCP server has been configured and is active, it can begin providing IP addresses to clients. These assignments will appear in the DHCP Lease table. To view it, open the WebUI and navigate to Configuration > DHCP. The DHCP Lease table appears automatically.