What is the correct destination UDP port number for a DHCPDISCOVER message?

The correct destination UDP port number for a DHCPDISCOVER message is 67. This is part of the Dynamic Host Configuration Protocol (DHCP), which operates on the client-server model to dynamically assign IP addresses and other network configuration parameters to devices on a network.

When a client wants to discover available DHCP servers, it sends a DHCPDISCOVER message as a broadcast on its local subnet. The message is directed to port 67 on the DHCP server, which is designated for handling DHCP requests from clients.

To elaborate, while port 68 is used by the client to receive messages from the DHCP server, port 67 is specifically the listening port for the server to process incoming requests. This distinction is critical in the DHCP process, as proper port allocation ensures that messages reach the correct destination and that the communication between the client and server occurs seamlessly.

The other options represent different services or mechanisms: port 53 is used for DNS (Domain Name System) traffic, port 80 is for HTTP (Hypertext Transfer Protocol) web traffic, and although port 68 is relevant to DHCP, it is not the port that a DHCPDISCOVER message is aimed at. Thus, understanding the function of port 67 is essential in DHCP operations.