8.4 The Network Layer
8.4.1 Routing occurs at the network layer
If the MAC address matches the address burned into the NIC card the Data Link Layer passes the data to the Network layer. If the MAC address is all one's the data is also passed to the Network Layer. When the Network Layer receives the packet, it uses the packet's network address to route beyond the local network. Routing allows the Network Layer to transfer data packets across the internetwork, from a source to a destination, and to choose the best path by which it is most efficient to deliver the packet.