Technical Tip: DHCP Options

[Markus_M]

Description

This article describes how to configure DHCP options on FortiGate.

Scope

Any currently supported version of FortiGate.

Solution

The screenshot below shows that the advanced DHCP options are enabled by default (under 'Advanced' menu).
This can be found under Network -> Interfaces -> <interface>.
Scroll down to see the DHCP Server options.

The default DHCP advanced settings are enabled by default. Confirm they are enabled with the following CLI command:

# config system settings

set gui-dhcp-advanced enable

end

The FortiGate DHCP options can be configured under DHCP server settings.

The server options are shown below. The DHCP server sends these options to all of the clients. 

The client options (for example, <if client is of vendor 'Name'>) are configurable at the interface level (see this article).

# config system dhcp server

edit 1

# config options

edit 1

set code 63

set value <HEX>         <----- Add HEX without a colon ':'.

end

end

end

Only a single value can be configured under each DHCP option with the HEX type. There's a possibility to configure multiple values with type string.

# config options

edit 1

set type string

set value "0x63,0x82,0x53,0x63"

next

end

Related links:

https://docs.fortinet.com/document/fortigate/6.0.0/cli-reference/536925/system-dhcp-server-dhcp6-ser...
https://help.fortinet.com/fos60hlp/60/Content/FortiOS/fortigate-networking/Interfaces/DHCP%20servers...