Technical Tip: Clients are receiving DHCP leases from FortiGate despite the relay agent being configured

The FortiGate was initially configured to provide DHCP leases to internal clients. However, it was later reconfigured to relay requests to an external DHCP server.

Before:

After:

This configuration will not disable the DHCP server on the FortiGate and must delete the DHCP configuration in the CLI.

FGT # config  system  DHCP server

FGT (server) # sh

config system dhcp server

    edit 6

        set dns-service local

        set default-gateway 192.168.11.1

        set netmask 255.255.255.0

        set interface "VM"

            config ip-range

                edit 1

                    set start-ip 192.168.11.2

                    set end-ip 192.168.11.254

                next

            end

    next     

end

To delete the DHCP lease use the following command:

FGT (server)
   delete 6
end