What type of message is an ARP response?

An ARP (Address Resolution Protocol) response is a unicast message. This occurs after a device has sent out an ARP request as a broadcast message to all devices on the local network segment, asking for the MAC address associated with a specific IP address. The device that recognizes its IP address sends back an ARP response directly to the requesting device's MAC address, thus establishing a one-to-one communication.

This method of responding ensures that only the specific device that made the request receives the MAC address information, which is essential for efficient network communication. Using unicast minimizes unnecessary network traffic that would result from broadcasting the response to all devices, as would be the case if it were sent as a broadcast message.

The other types of messages, such as multicast and anycast, involve multiple recipients or specific groups of devices, which does not apply to ARP response scenarios where the communication is directed to a single device.