Technical Tip: How to define DHCP client address range and exclude IP range

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Description
This article describes steps to define exclude range.

Solution
FortiGate DHCP server used to assigns an IP address and other information to each host on the network so it can communicate efficiently with other endpoints.
From the GUI, define DHCP address range and MAC address reservation is possible.  

If a large address range is get  for the DHCP server and if exclude specific IP or a range of addresses is needed, that will not be assigned to connecting client to configure the exclude range in the DHCP server setting from CLI.

# config system dhcp server
    edit <server_entry_number>
    # config exclude-range
        edit <sequence_number>
            set start-ip <address>
            set end-ip <address>
        end
    end
end

For example, let’s assume the DHCP client address range has been defined  as 192.168.1.2 to 192.168.1.254.

Exclude IP 192.168.1.3 and address range 192.168.1.10-192.168.1.20 from getting assigned to any DHCP client by FortiGate DHCP server to exempt these IPs in DHCP server settings.

# config system dhcp server
    edit 1
    # config exclude-range
    edit 1
        set start-ip 192.168.1.3
        set end-ip 192.168.1.3
    next
        edit 2
        set start-ip 192.168.1.10
        set end-ip 192.168.1.20
    next
  end