A network device needs to discover a DHCP server in order to obtain an IP address, it will send a broadcast message called DHCPDISCOVER. This broadcast message is sent to the broadcast address (255.255.255.255) on the local network segment. DHCP servers listen for these broadcast messages, and the first server to respond will provide the device with an IP address. The default gateway, unicast address and link-local address are not the destination address to send DHCP request.