- Network > DHCP > DHCP Server
The following section describes each component of the DHCP server. Before you configure a DHCP server, you should already have configured a Layer 3 Ethernet or Layer 3 VLAN interface that is assigned to a virtual router and a zone. You should also know a valid pool of IP addresses from your network plan that can be designated to be assigned by your DHCP server to clients.
When you add a DHCP server, you configure the settings described in the table below.
DHCP Server Settings
Name of the interface that will serve as the DHCP server.
Automode enables the server and disables it if another DHCP server is detected on the network. The
disabledsetting disables the server.
Ping IP when allocating new IP
If you click
Ping IP when allocating new IP, the server will ping the IP address before it assigns that address to its client. If the ping receives a response, that means a different firewall already has that address, so it is not available for assignment. The server assigns the next address from the pool instead. If you select this option, the Probe IP column in the display will have a check mark.
Specify a lease type.
Specify the stateful pool of IP addresses from which the DHCP server chooses an address and assigns it to a DHCP client.
You can enter a single address, an address/<mask length>, such as 192.168.1.0/24, or a range of addresses, such as 192.168.1.10-192.168.1.20.
Optionally specify an IP address (format x.x.x.x) from the IP pools that you do not want dynamically assigned by the DHCP server.
If you also specify a
MAC Address(format xx:xx:xx:xx:xx:xx), the
Reserved Addressis assigned to the firewall associated with that MAC address when that firewall requests an IP address through DHCP.
None(default) or select a source DHCP client interface or PPPoE client interface to propagate various server settings to the DHCP server. If you specify an
Inheritance Source, select one or more options below that you want
inheritedfrom this source.
One benefit of specifying an inheritance source is that DHCP options are quickly transferred from the server that is upstream of the source DHCP client. It also keeps the client’s options updated if an option on the inheritance source is changed. For example, if the inheritance source firewall replaces its NTP server (which had been identified as the
Primary NTPserver), the client will automatically inherit the new address as its
Check inheritance source status
If you selected an
Inheritance Source, click
Check inheritance source statusto open the Dynamic IP Interface Status window, which displays the options that are inherited from the DHCP client.
Specify the IP address of the network gateway (an interface on the firewall) that is used to reach any device not on the same LAN as this DHCP server.
Specify the network mask that applies to the addresses in the
For the following fields, click the drop-down and select
inherited, or enter the IP address of the remote server that your DHCP server will send to clients for accessing that service. If you select
inherited, the DHCP server inherits the values from the source DHCP client specified as the
The DHCP server sends these settings to its clients.
Custom DHCP options
Addand enter the
Nameof the custom option you want the DHCP Server to send to clients.
Option Code(range is 1-254).
Option Code 43is entered, the Vendor Class Identifier (VCI) field appears. Enter a match criterion that will be compared to the incoming VCI from the client’s Option 60. The firewall looks at the incoming VCI from the client’s Option 60, finds the matching VCI in its own DHCP server table, and returns the corresponding value to the client in Option 43. The VCI match criterion is a string or hex value. A hex value must have a “0x” prefix.
Inherited from DCHP server inheritance sourceto have the server inherit the value for that option code from the inheritance source instead of you entering an
As an alternative to this option, you can proceed with the following:
Option Type: Select
Hexadecimalto specify the type of data used for the Option Value.
Option Value, click
Addand enter the value for the custom option.