Set up Smoothwall Appliance as a DHCP Server

You can use your Smoothwall Appliance as a DHCP Server to automatically allocate IP addresses and other network settings to connected clients.

To use your Smoothwall Appliance as a DHCP relay to forward requests across LAN interfaces to a remote DHCP Server, see Set up Smoothwall Appliance as a DHCP Relay .

Step 1: Turn on Server mode

1. Go to Services > DHCP > Global.
2. In the Global settings section, select the Enabled checkbox.
3. Ensure the Server option is selected, not Relay (forwarding proxy).
4. To generate logs you can report on from Reports > Logs > System under the DHCP server section, ensure the Enable logging checkbox is selected.
5. Select Save.

Step 2: Configure your DHCP server settings

Go to Services > DHCP > DHCP server.

DHCP subnets

Add a DHCP subnet

1. In the DHCP subnet section:
   1. Select an Empty slot from the dropdown.
   2. Click Select.
   3. Enter a Subnet name.
2. In the Settings section:
   1. Enter the Network IP address that, when combined with the Netmask, specifies the subnet's network ID.
   2. Enter the Netmask.
   3. Enter the values that requesting network hosts receive for Primary DNS, Default gateway and (optionally) Secondary DNS.
3. (Optional) Select Advanced to configure additional settings:
   • Primary WINS and Secondary WINS server fields.
   • Primary NTP and Secondary NTP server fields. Enter the IP address of your Smoothwall Appliance, so clients use your Appliance’s time.

       Note

     You must be using Option 1: Have a time server running continuously for your Smoothwall Appliance time settings.

   • You can adjust the Default lease time (mins) assigned to network hosts that do not request a specific lease time from the default value of 60.
   • You can adjust the Max lease time (mins), which prevents network hosts from requesting and being granted overly long DHCP leases, from the default value of 120.
   • The Trivial File Transfer Protocol (TFTP) server that devices use from the network when starting up, and the Network boot filename for the network client to download from the selected TFTP server.
   • Domain name suffix appended to the requesting host's hostname.
   • Automatic proxy config URL that clients use for determining proxy settings, which references a Proxy Auto-Config (PAC) file.
   • Custom options to enter the IP address or text.

Edit or delete a DHCP subnet

1. In the DHCP subnet section, select a DHCP subnet from the dropdown and click Select.
2. Select Delete, or edit the fields then select Save.

Dynamic DHCP Ranges

Use Dynamic ranges to provide the DHCP server with a pool of IP addresses in the DHCP subnet that it can dynamically allocate to requesting hosts.

Add a Dynamic DHCP Range

1. In the DHCP subnet section, select a DHCP subnet from the dropdown and click Select.
2. In the Add a new dynamic range section:
1. Enter the Start address and End address of an IP range the DHCP server uses to supply dynamic addresses.

     Note

   Ensure this range doesn’t overlap with the statically assigned IP addresses of other devices on your LAN to prevent IP address conflicts and connectivity issues.

2. (Optional) Enter a descriptive Comment.
3. Ensure the Enabled checkbox is selected.
4. Select Add dynamic range.

Edit or delete a Dynamic DHCP range

In the Current dynamic ranges section, select the checkbox in the Mark column.

• To delete, select Remove dynamic range.
• To edit:
1. Select Edit dynamic range.
2. In the Add a new dynamic range section, edit the fields as needed.
3. Select Add dynamic range.

Static DHCP assignments

Use Static assignments to allocate fixed IP addresses to nominated hosts by referencing the unique MAC address of the requesting host’s network interface card (NIC).

Add a static DHCP assignment

1. In the DHCP subnet section, select a DHCP subnet from the dropdown and click Select.
2. In the Add a new static assignment section:
1. Enter the MAC address of the network host’s interface.
2. Enter the IP address to assign to the host.
3. (Optional) Enter a descriptive Comment.
4. Ensure the Enabled checkbox is selected.
5. Select Add dynamic range.

Add a static DHCP assignment from the ARP table

1. In the DHCP subnet section, select a DHCP subnet from the dropdown and click Select.
2. In the Add static assignment from ARP table section:
1. Select the checkbox in the Mark column for one or more MAC addresses.
2. Select Add static from ARP table.

Edit or delete a DHCP assignment

In the Current static assignments section, select the checkbox in the Mark column.

• To delete, select Remove static.
• To edit, select Edit static.
1. In the Add a new static assignment section, edit the fields as needed.
2. Select Add static.

Step 3: Check your setup

1. Go to Services > DHCP > Global.
2. Ensure the Enable logging checkbox is selected.
3. Connect a client device to your network.
4. Go to Reports > Logs > System.
5. For Section, select DHCP server.
6. Select Update.
7. Check the System log section for configuration errors.