DHCP Server

With DHCP Server, your Synology NAS can act as a DHCP server and assign dynamic IP addresses to DHCP clients within your local network. DHCP (Dynamic Host Configuration Protocol) is a network management protocol required on IP networks. DHCP Server dynamically assigns an IP address and other network configuration parameters to each device in the same network, and all devices in this network will communicate with each other with the IP addresses from the server.

To enable DHCP Server:

1. Go to DHCP Server > Network Interface.
2. Select a network interface (e.g. LAN 1) to assign IP addresses to, and click Edit.
3. In the DHCP Server tab, select Enable DHCP Server.
4. Specify the following DHCP settings:
   • Primary DNS
   • Secondary DNS (optional)
   • Domain name (optional)
   • Enable Web Proxy Automatic Discovery (optional)
5. Set up at least one subnet. For the subnet setup, click Create to specify the following information:
   • Start IP address
   • End IP address
   • Netmask
   • Gateway
   • Address lease time
6. Click Create to show the created subnet in the list.
7. After you create enough subnets, remember to enable at least one subnet.
8. Click OK.

DHCP Clients

You can find a list of DHCP clients and their network configurations (e.g. MAC address, IP address, hostname, the amount of time left before the DHCP lease expires, and the reservation status).

1. Go to DHCP Server > Network Interface and select one desired interface.
2. Click Edit > DHCP Clients to find the clients and the details.

To manage IP addresses for DHCP clients:

You can have a client always receive the same IP address during DHCP lease renewal and manage these clients.

• To add DHCP clients: Click Add to assign the IP address to the client device.
• To reserve the IP address: Click the lock icon to reserve the IP address for the current device.
• To cancel the reservation: Click the lock icon to allow the current IP address to be used by another device after the address lease time passes.

To search for DHCP clients:

1. Click the funnel icon on the top right corner.
2. Select one of the search criteria below:
   • All: List all the DHCP clients and DHCP reservations.
   • DHCP clients: List all the DHCP clients with reserved or unreserved IP addresses.
   • DHCP reservations: List all reserved IP addresses. A reserved IP address may not be paired with any device yet.

DHCP Options

After you specify the DHCP options, your Synology NAS as the DHCP Server can send out related information to the DHCP clients in a certain subnet.

To specify DHCP options for a subnet:

1. Go to DHCP Server > Network Interface.
2. Select the desired network interface and click Edit.
3. In the DHCP Server tab, go to the Subnet list.
4. Do either action below:
   • To specify DHCP options for an existing subnet: Select the desired interface and click Edit.
   • To create a subnet and specify its DHCP options: Click Create and specify the subnet settings.
5. Select the wanted DHCP options; to specify the corresponding values, click on the blank fields for editing.
6. Click OK.

For the supported DHCP options and their value limitations, please refer to the table below:

Vendor

DHCP clients of different vendors may require additional DHCP information. By setting up DHCP options for the vendors, your Synology NAS can provide such details to the clients.

To know the DHCP options supported by each vendor, please contact the specific vendors for details.

To add vendors:

1. Go to DHCP Server > Vendor.
2. Click Create to specify the vendor and its DHCP options:
   • Name: Specify the vendor's name.
   • Code: Specify the numeric code of the DHCP option.
   • Value: Specify the option value.
   • Add: Add a DHCP option.
   • -: Delete a DHCP option.
3. Click Create to finish the setup.

To edit DHCP options for vendors:

1. Go to DHCP Server > Vendor.
2. Select the desired vendor and click Edit to manage its DHCP options.
3. Click OK.

PXE

Your Synology NAS can act as a DHCP server to implement the setup of PXE (Pre-Boot Execution Environment). PXE is a network environment that allows client devices to boot up using a network interface rather than a data storage device (e.g. hard disks).

When PXE is implemented, a boot loader can be stored on your Synology NAS or a remote TFTP server, and client devices can boot up over the network using the boot loader.

To use your Synology NAS as a boot loader server:

1. Make sure you have selected Enable TFTP service (at Control Panel > File Services > TFTP).
2. Select a folder that hosts the boot loader file as the TFTP root folder.
3. Make sure at least one DHCP subnet is enabled (at DHCP Server > Network Interface).
4. Go to DHCP Server > PXE.
5. Select Enable PXE (Pre-boot Execution Environment).
6. Select Local TFTP server and select the boot loader file.
7. Click Apply to save the settings.

To use remote TFTP server as a boot loader server:

By using a remote TFTP server as a boot loader server, you can allow clients to boot up without having to change the current network infrastructure.

1. Make sure at least one DHCP subnet is enabled (at DHCP Server > Network Interface).
2. Go to DHCP Server > PXE.
3. Select Enable PXE (Pre-boot Execution Environment).
4. Select Remote TFTP server, and specify the server IP address and the file path of the boot loader file.
5. Click Apply to save the settings.