31 Days Before Your CCENT Certification

CCNA Discovery 1, Chapter 3

3.3.3: Hosts on Ethernet networks identify themselves with a media access control (MAC) address. When a host communicates over an Ethernet network, it uses its MAC address as the source and the recipient’s MAC address as the destination. All hosts on the network that receive the frame compare their MAC address to the destination address and respond if there is a match.

3.3.5: In the hierarchy of the Internet, a MAC address provides a unique identity for a host but does not provide information about the host’s location on the network. With millions of hosts on the Internet, it would be unreasonable for each host to look at each communication to decide if it is the recipient. The sending host would have to broadcast ...