Packet Transmission Continued
MAC address checking occurs at the Network Interface layer of the TCP/IP model or the Data Link layer (layer 2) of the OSI model.
IP address checking occurs at the Internetwork layer of the TCP/IP protocol stack, which is equivalent to the Network layer (layer 3) of the OSI model.
On a TCP/IP network, both a MAC address (physical) and an IP address (logical) are required to send data.
The MAC address, at the Network Interface layer, uniquely identifies a specific device on any network.
The IP address, at the Internetwork layer, identifies a specific host on a specific network.