There are three types of network transmissions at layer 2, the Data Link Layer. These are unicast, multicast, and broadcast:
- Unicast: In a unicast transmission, the frame is sent to only one destination MAC address or device on the network, as follows:
- Multicast: In a multicast transmission, a single stream of one or more frames is sent to multiple devices on the network. Multicast addresses take 01-00-5E as the first 24 bits of the MAC address:
- Broadcast: A broadcast is a one-to-all transmission, where the frame originates from a single source device, but is sent to all devices on the LAN. In a broadcast MAC address all the 48 bits are 1, resulting in the address FF-FF-FF-FF-FF-FF: