How to set up pfSense DHCP server

DHCP (Dynamic Host Configuration Protocol) is a network protocol used by devices (DHCP clients) to obtain IP addresses and other network settings automatically. pfSense includes a DHCP server which can be configured to assign IP addresses to devices on your network.

Here’s how to set up the DHCP server on pfSense:

  1. Access the pfSense Dashboard: Open a web browser and navigate to your pfSense dashboard. The default address is usually http://192.168.1.1. Use your username and password to log in.
  2. Navigate to the DHCP Server Settings: From the top menu, click on ‘Services’ and then ‘DHCP Server’.
  3. Select the Interface: You will see a tab for each available interface. Choose the interface for which you want to enable the DHCP server. For a typical home or small business network, you would select ‘LAN’.
  4. Enable the DHCP Server: On the interface settings page, check the ‘Enable DHCP server on LAN interface’ box (replace ‘LAN’ with your chosen interface if different).
  5. Configure DHCP Range: In the ‘Range’ section, input the start and end IP addresses that the DHCP server will use when assigning IP addresses to clients. Make sure that the range is within the subnet of the interface’s IP address. For example, if your LAN interface is set to 192.168.1.1, your range could start at 192.168.1.100 and end at 192.168.1.200.
  6. Set Additional Options (Optional): You can configure additional options as needed. For example:
    • DNS servers: You can specify DNS servers to be assigned to DHCP clients. If left blank, the DNS servers defined in the system’s general settings will be used.
    • Gateway: You can specify the gateway to be used by DHCP clients. If left blank, the IP address of the interface (the pfSense LAN IP) will be used.
    • Domain Name: You can specify the domain name for the clients.
    • Lease Time: You can adjust the default lease time, which is the length of time that an IP address is ‘leased’ to a client before it expires and must be renewed.
    • Reservations: If you want certain devices to always receive the same IP address, you can add a ‘static mapping’ at the bottom of the page. Enter the MAC address of the device, the desired IP address, and any other required information.
  7. Save and Apply Changes: Once you have configured the DHCP settings to your liking, click on the ‘Save’ button at the bottom of the page. Then click on ‘Apply Changes’ at the top of the page to start the DHCP service.

Now, any device connected to your network that is set to obtain an IP address automatically should receive an IP address from the pfSense DHCP server, along with any other settings you’ve configured. Remember to ensure that DHCP is not being provided by any other device on the same network (like another router) to prevent IP address conflicts.